Tag: Veterinary Public Health (Food Hygiene)

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* Setting a dinner table for wildlife can affect their risk of disease

The findings, published in the journal Ecology Letters, have implications for human health and wildlife conservation, and contain practical suggestions for wildlife disease management and a roadmap for future study. Supplemental feeding–when people provide food to wildlife–is growing more common. As people move into previously undeveloped areas and habitat is lost to development or agriculture, wildlife ecology changes. Natural sources of food often decrease, and new abundant sources, provided by people, appear. Sometimes these are intentional, like backyard bird feeders or winter feeding stations for an elk herd in a national park; sometimes they’re accidental, like landfills or poorly secured garbage cans. The resulting changes in behavior and nutrition can affect how diseases impact wildlife.

“We knew of studies of supplemental feeding showing both increases and decreases in parasitism and disease, but no one had synthesized them,” said Daniel Becker, a doctoral student in the Odum School of Ecology and the study’s lead author. “We wanted to know if there was an overall net tendency, and we wanted to know what could explain the different responses.” The researchers pulled together over 20 published studies of supplemental wildlife feeding and infectious disease to understand trends in infection patterns and to create predictive models of pathogen transmission. “We found that there are several different mechanisms at work,” Becker said. With pathogens like bacteria or viruses that are spread by close contact, food sources that attract large numbers of animals can encourage transmission, including transmission from one species to another–even to humans. This is suggested with the spread of Nipah virus in Malaysia, where infected fruit bats are attracted to fruit trees planted by farmers, bringing them into contact with livestock and people.

Even when the food provided is very nutritious–and therefore potentially able to improve an animal’s immune function–in most cases that is not enough to overcome the exposure risk of being in the midst of a large group with frequent aggressive contacts over resources. In many cases, the food is not nutritious enough to help and can even impair animals’ immune defenses. An example of this is when tourists in the Bahamas feed rock iguanas grapes, which are not part of their natural diet. Their overall condition is impaired and levels of infection by hookworms are higher. For diseases caused by parasites such as tapeworms and flukes that require multiple hosts to complete their life cycles, however, the results suggest a different process. Animals that glean food from a landfill or garbage can are less likely to be exposed to such parasites, reducing their levels of disease. When foxes, for instance, find their food at a landfill instead of hunting for small rodents, which are commonly infected with worms, they are less likely to become infected themselves. Knowing what happens in different contexts could help wildlife enthusiasts and managers minimize the risk of disease if they choose to supplement wildlife diets.

“For intentional feeding sources like bird feeders, we expect parasites like bacteria and viruses to increase, so spacing these resources apart can help reduce the high contact rates driving transmission,” Becker said. “And cleaning feeders periodically can help limit the build-up of infectious stages in the environment that occurs when lots of animals become more sedentary.” Improving the nutritional content of the food being provided is another strategy that could help boost wildlife immune function and allow them to better resist infection, and supplemental food sources could also be used to distribute vaccines or treatment, Becker said. The authors also provided a roadmap for future research, including collaborating with existing citizen science networks to gather data. “We need field experiments, we need long-term observational studies, and we need to develop models focusing on environmentally transmitted parasites like worms; those are areas where we’re lacking information,” Becker said. “This is an issue that’s not going away, so we need to understand it.” “For a lot of people, feeding animals provides a crucial connection to nature, increases their appreciation of wildlife and presents opportunities for outreach and education,” said study co-author Sonia Altizer, the UGA Athletic Association Professor of Ecology and Odum School associate dean. “We don’t want to suggest that all feeding of wildlife should be avoided, but we do need to find ways to minimize the risks for human and wildlife health.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/03/150330122617.htm  Original web page at Science Daily

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‘Hidden’ emissions in traded meat calculated by researchers

An international team of researchers has, for the first time, estimated the amount of methane (CH4) and nitrous oxide (N2O) that countries release into the atmosphere when producing meat from livestock, and assigned the emissions to the countries where the meat is ultimately consumed. They found that embodied, or “hidden,” emissions in beef, chicken and pork have increased by 19% over the past 20 years, and that there is currently a global instability caused by a large number of countries contributing to the production of emissions in another country. Russia was singled out as the biggest importer of embodied emissions in meat over that period, consuming more emissions than it produced, and receiving the majority of its emissions from Brazil and Argentina. The researchers also revealed substantial internal trade flows of emissions between European countries. The results, which have been published in IOP Publishing’s journal Environmental Research Letters, add further weight to the idea of ‘consumption-based accounting’, where countries account for the emissions from the products they consume as well as the products they produce. Lead author of the research, Dr Dario Caro, from the Carnegie Institution for Science (Stanford) and the University of Siena, said: “Our analysis of livestock emissions embodied in the international trade of meat highlights the regional variation in emissions intensities and quantifies a significant barrier to effective regional and national policies regulating livestock emissions. “A developing country, for example, may lack specific infrastructure and therefore emit large amounts of GHGs when producing meat from livestock. These emissions can be increased when demand from more developed countries is placed on this country to produce more meat. “At the moment, all existing policies neglect any emissions embodied in trade, so countries are not accounting for the emissions they may be causing in other countries.” Previous studies have quantified the carbon dioxide (CO2) emissions embodied in products traded internationally, but there has been limited attention paid to other greenhouse gases such as CH4 and N2O. Global emissions of CH4 and N2O account for approximately 27.7% of total radiative forcing since the pre-industrial era, and, in 2001, livestock accounted for 25% of this. Thus, direct emissions of CH4 and N2O from livestock worldwide represent approximately 9% of total anthropogenic GHG emissions. CH4 is emitted into the atmosphere as a by-product of the normal digestive system of ruminant livestock, and is also produced alongside N2O when the components of manure are broken down by bacteria.

In their study, the researchers, from the Carnegie Institution for Science, the University of Siena and University of California (Irvine), analysed data from 237 countries and found that between 1990 and 2010, 36.1 Mt of CO2-equivalent (CO2-eq) emissions were related to meat produced in one country and consumed in a different country. The largest amount of embodied emissions were from beef (26.7 Mt of CO2-eq), pork (7.3 Mt of CO2-eq) and chicken (2.1 Mt of CO2-eq) respectively. In Europe, meat exported from France to Italy and Greece embodied 1.4 Mt and 1.2 Mt of CO2-eq emissions respectively, and Italian imports of meat from Poland, Germany and Netherlands embodied 0.7, 0.6, and 0.7 Mt of CO2-eq emissions, respectively. Dr Caro continued: “While our study exclusively focused on the direct non-CO2 emissions released from live breeding animals, other indirect CO2 emissions embedded in the life cycle of meat products occur and were not included. “Future advancements should therefore take into account the total production process and transportation, including CO2 emissions as well as land, water and energy use occurring in the supply chain.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2014/11/141113195152.htm  Original web page at Science Daily

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Study finds fears that pet ponies and donkeys traded for horsemeat in Britain unfounded

Fears that pet ponies and donkeys are being traded for horsemeat are unfounded, reveals research published online in the Veterinary Record. Buyers want larger size animals to obtain the maximum meat yield, so go for thoroughbreds and riding horses, the study indicates. The researchers looked at the animals put up for sale at seven randomly selected auction markets in Britain in August and September 2011, and the type preferred by dealers buying on behalf of abattoirs. The auctions were in North Yorkshire, West Yorkshire, Wales (Powys), Berkshire and Cheshire and traded equines only, but of all types, breed and age. Their study was prompted by public concerns about the possible dispatch to slaughter of pet horses and donkeys and unwanted thoroughbred racehorses. The authors examined 384 animals, which included a broad range of cross breeds, thoroughbreds, and ponies, and found out the destination of the 294 that were sold. Ninety were either withdrawn from sale or didn’t reach their reserve price. Just 68 were bought on behalf of the three main horse abattoirs operating in Britain in 2011, while 226 were bought by other types of buyer.

Almost half of the horses and ponies put up for sale were geldings (42%), followed by mares (30%), fillies (16%), colts (10%), and stallions (2%). Height varied from 9 to 17 hands while age ranged from under 12 months to 21 years. Animals destined for the meat trade were around 2.5 times as likely to be larger — taller than 15 hands — than those bought by other outlets. Horsemeat buyers avoided ponies and cross breeds and instead opted for thoroughbreds and riding horses (43%). The price per hand for meat trade animals varied from £1.31 to £57.79. Dealers buying on behalf of abattoirs were twice as likely to purchase animals that had some physical abnormality, including flesh wounds, burn injuries, bruises, swellings, bleeding, discharge, hair loss, or deformity, as those buying for other outlets (26% compared with 13%). And 16% of the animals destined for an abattoir were lame. The authors conclude: “Equine buyers supplying horse abattoirs in Great Britain had a preference for purchasing larger animals and they avoided buying ponies. This is thought to reflect a preference for animals which provide a maximum meat yield from the carcase to cover the cost of transport, slaughter, and dressing.” They add: “A relatively small proportion of unwanted ponies and small horses were destined for the meat trade. In general, the findings from this study did not support the view that the abattoir industry focused on profiting from the slaughter of pet ponies.”

Science Daily
July 23, 2013

Original web page at Science Daily

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Vets and medical doctors should team up to tackle diseases transmitted from animals to humans

A new study at the Institute of Tropical Medicine (ITM) in Antwerp analyses the impact of animal brucellosis and bovine tuberculosis (BTB) on animals and people in urban, peri-urban and rural Niger. The World Health Organization (WHO) ranks them as major zoonoses, infectious diseases transmitted between species. The research maps risk factors for transmission of these diseases from animals to humans, indicating that closer collaboration between medical doctors and veterinarians is required. Interviews with the local population identified the main risk factors for transmission; consumption of unpasteurised milk, lack of hygiene in households, presence of coughing animals in the herd, and absence of quarantine. “Milk is an important source of protein in Niger. Animals graze in rural areas, but are brought to the city when lactating in order to be as close as possible to the consumer. Mapping these kind of dynamics provides vital information about the diseases and how they are transmitted,” said Abdou Razac Boukary about his doctoral research at ITM and the University of Liège (Ulg). The study concludes that it is crucial to address the interlinks between humans, animals and the environment to control animal brucellosis and BTB. They are both an economic and a public health threat. While contagion is extremely unlikely in industrialised countries, the largest part of the world’s population lives in areas where animal brucellosis and bovine tuberculosis are not under control. Hence, ITM calls for increased collaboration between animal and human health specialists in a so called “One Health” approach.

“We should not forget that more than 60% of human pathogens originate from animals. But raising awareness about these relatively unknown diseases is also crucial from an economic perspective. According to an African saying, if livestock die so does the village,” said ITM scientist Eric Thys, co-promoter of the thesis. Abdou Razac Boukary, an agronomist and advisor to the government of Niger, brought together a group of human and animal health specialists for his PhD research. Boukary studied brucellosis and BTB in over 1100 households keeping livestock. He collected nearly 5000 blood samples for brucellosis and tested almost 400 cattle for BTB. Such a large scale approach involving animal and human health specialists is still a rarity. Results show that around 13% of herds included animals infected with brucellosis. It was found that animals below the age of one were more likely to fall ill than animals aged 1-4 years. Around one in hundred cows were found to be infected with BTB. Analysis of samples taken at the abattoir of Niamey showed that cows were significantly more affected by BTB than other categories of cattle. The research also characterised a new profile of Mycobacterium bovis bacterium (SB1982) which has never been reported before. In humans, brucellosis induces undulating fever, sweating, weakness, anemia, headaches, depression, as well as muscular and bodily pain, testicular inflammations in men and spontaneous abortion in pregnant women. Human tuberculosis from animal origin can affect the lungs but is often located in others part of the body. While contagion is extremely unlikely in industrialised countries, the largest part of the world’s population lives in areas where animal brucellosis and bovine tuberculosis are not under control.

Science Daily
May 14, 2013

Original web page at Science Daily

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The risks of antibiotic resistance and consumption: Learning with hands-on activities

An innovative laboratory-based summer project — Microbiology recipes: antibiotics à la carte — addressing antibiotic resistance and natural antibiotics has been shown to be an effective strategy to increase high school students’ awareness of antibiotic resistance and the relevance of rational antibiotic use. In contrast to traditional educational interventions, which mainly rely on large-scale information campaigns, this project’s instructional design was devised to take advantage of the acknowledged benefits of laboratory work, by encouraging the participants’ active engagement in their learning. The study is presented by a group of researchers from the University of Porto, Portugal in the latest issue of PLOS ONE. Microbiology recipes: antibiotics à la carte is a one-week long inquiry-based summer project implemented in the scope of Porto’s Junior University — a summer school-based initiative fostered by the University of Porto, which seeks to promote Science & Technology, Arts, Humanities and Sports education amongst elementary and high school students (aged 11 to 17). Each year, the University’s Faculties open their doors to approximately 5000 students, who are invited to take part in a wide range of projects designed by university lecturers and implemented by undergraduate and graduate students in a relaxed, but didactically-focused environment.

The widespread of bacterial resistance to antibiotics is a major public health issue that demands concerted educational interventions to raise public awareness and promote judicious antibiotic use. Consistently with this perceived need, several educational programs have been put forth and numerous didactic resources have been developed. However, reliable indicators of the efficacy of most of these resources have not been consistently provided so far. Furthermore, studies reveal that the general public remains unaware of basic aspects related to the modes of action of antibiotics and frequently engage in misinformed behaviors. Considering that educational programs targeting young people can contribute to a future generation of scientifically literate antibiotic users, the group of researchers from the University of Porto developed, implemented and assessed a hands-on interventional program to raise young people’s interest and consciousness about the consequences of antibiotic resistance and foster their sense of self-responsibility in this regard. Maria João Fonseca, one of the researchers involved in the study says: “We were interested in sparking students’ interest, and scaffolding their scientific reasoning about the processes involved in antibiotic resistance and natural antibiotics’ activity, by prompting the connection between observable phenomena and the underlying ideas. We found that, by combining diverse activities, ranging from bioinformatics exercises to natural antibiotic testing, it was possible to address misconceptions, improve students’ understanding and promote the development of procedural skills.” Fernando Tavares, the coordinator of the project, adds “this study evidences the benefits of incorporating hands-on activities in science education programs. We believe that the data gathered illustrate how an informal educational environment such as the one provided by the Junior University can have a measurable and effective impact on our students, and contribute to promote scientific literacy about pressing socio-scientific issues amongst future generations.”

Science Daily
October 2, 2012

Original web page at Science Daily

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Chilling methods could change meat tenderness

In a recent paper published in the Journal of Animal Science, meat scientists report that a method called blast chilling could affect pork tenderness. Researchers at the USDA-ARS, Roman L. Hruska US Meat Animal Research Center (USMARC) recently conducted a study that compares pork longissimus muscle (LM) tenderness and other meat quality traits between different stunning methods and carcass chilling rates at slaughter facilities. The pigs used in this study came from one barn on a commercial finishing operation. Pigs were taken to one of three slaughter facilities. Plant A used CO2 stunning and conventional spray chilling; Plant B used CO2 stunning and blast chilling; and Plant C used electrical stunning and blast chilling. Blast chilling is a rapid cooling of the muscles for at least 45 minutes at less than negative ten degrees Fahrenheit,” said Steven Shackelford of USMARC. Blast-chilling systems are used to increase packing plant throughput, enhance food safety, and improve meat quality, particularly water-holding capacity of muscles from stress-susceptible pigs.

After slaughter, carcasses were cooled by blast chilling or conventional spray chilling. The researchers used a loin from the left side of the carcass for evaluation. They sent the loins to the USMARC, where the loins were refrigerated and weighed for purge loss. Purge loss is the loss of fluid from meat. At 15 days post mortem, the meat was cooked and the researchers measure the LM slice shear force. Slice shear force is a measurement of meat tenderness. The higher the shear force, the tougher the meat. They also tested the meat samples for marbling, muscle fiber length, moisture content, color, the break down of proteins, and intramuscular fat content. The researchers found no loin quality advantages from blast chilling. They did find a 13-fold increase in excessively tough samples from blast chilling. This research shows that differences in chilling systems among pork packing plants can have a strong influence on loin chop tenderness. “This study showed that blast chilling can have a very substantial negative impact on tenderness. So there are trade-offs that must be considered,” said Shackelford.

The findings are surprising because past literature suggests that blast chilling had little importance. The researchers believe this is due to changes in genetics and production systems, which can affect chilling rate. The researchers also found that regardless of chilling method, CO2 stunning resulted in darker LM lean color and greater LM water-holding capacity than electrical stunning. For the future, the researchers would like to see studies that determine whether differences exist consistently across conventional and blast-chill plants over multiple seasons of the year and multiple production systems. “Given the real and perceived advantages of blast chilling, we think that more research is needed to determine optimal blast-chilling conditions for a balance of all meat quality traits and other economical issues,” said Shackelford.

Science Daily
September 18, 2012

Original web page at Science Daily

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Nunavik sled dogs need first aid and care too

In Nunavik, there are many dogs — sled dogs, pets, and strays — but no veterinarian, so the University of Montreal International Veterinary Group has given Andréanne Cléroux, a veterinary student, the mandate to design and deliver a first aid guide for dogs in northern Quebec. “The problem relates mainly to animal health care, immunization, and dog population control,” Cléroux explains. “We wanted to create a guide that would provide basic tools for pet owners so they can provide care to their animal while waiting to contact the remote veterinary consultation service to get advice from a veterinarian at the CHUV (University of Montreal Veterinary Hospital).” The initiative is part of the Support project in veterinary public health and animal health in Nunavik, which began in 2008 with the creation of the remote veterinary consultation service. Last year, Cléroux spent a month writing the guide before flying to Nunavik. During her one-week stay, she presented a draft of her work to several inhabitants of the town of Kuujjuaq. She was accompanied by the junior college student Emaly Bibeau Jonas, who provided interpretation between Inuktitut and French. “Through their comments, I was able to rework the guide to make it more simple, concise, and user-friendly,” says Cléroux, who was supervised by the Faculty of Veterinary Medicine’s Dr. Denise Bélanger, Dr. Cécile Aenishaenslin, and Dr. Josiane Houle.

The challenge, she notes, was to produce a manual that would address both those unfamiliar with animal health care and those who already have more advanced knowledge, such as dog sled drivers. “Dog mushers are great for recognizing and treating all kinds of medical conditions,” says Cléroux. With accompanying photographs, the guide covers everything from vaccination schedules, drug administration, and care of newborns, to sterilization, zoonotic diseases, fractures, and bandaging methods. Cléroux has also created a first aid kit that includes all the necessary material to provide the care described in the manual. “At the moment, there is only one kit available at the Makivik Corporation research center in Kuujjuaq. Our goal is to distribute one kit to each of the 14 communities in Nunavik.” This month, she’ll be travelling once again north of the 55th parallel to deliver copies of the official version of the guide to dog owners in Kuujjuaq. She will do the same in the communities of Quaqtaq and Puvirnituq, while providing first aid kits. “We will evaluate their use by the residents and then decide how to proceed with the other villages,” she says. “I hope our work will increase people awareness of veterinary public health issues and animal health, and that our tools will encourage them to promote animal health and care.”

Vaccination campaign Rabies is an often-cited problem in Nunavik. “It’s an endemic problem. There are reported cases every year,” notes Cléroux. The ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec (MAPAQ) visits the communities in Hudson Bay and Ungava Bay to conduct annual vaccination campaigns. They provide basic and antirabies vaccines. Local vaccinators are also present at other times of the year. “There is still room for improvement, but we must recognize that vaccination is more widespread than before,” says Cléroux. She experienced this first hand during her stay. At the invitation of MAPAQ, she organized a vaccination clinic, which to her surprise, drew dozens of people. “We saw 120 dogs and two cats in one afternoon!” she recounts, still amazed. “The children were leaning over our shoulders to watch us work and each had a story to tell.” This experience was “extremely rewarding” for the student. “I would like to continue working in these communities. I could go there from time to time to participate in immunization clinics or other projects that focus on animal and public health.”

Science Daily
June 26, 2012

Original web page at Science Daily

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Influenza virus A (H10N7) in chickens and poultry abattoir workers, Australia

In March 2010, an outbreak of LPAI A (H10N7) was identified in a biosecure intensive commercial poultry enterprise in New South Wales, Australia. For 8–14 days, 10–25 birds died each day, compared with the normal number of 2–6 birds per day. An egg production decrease of up to 15% was documented in the affected flocks. In contrast to other reported poultry outbreaks, respiratory signs were absent in the flock. All cloacal and tracheal swabs from 10 dead and 10 live birds submitted for influenza virus exclusion were positive by an influenza A matrix gene quantitative real-time reverse transcription PCR, and virus was detected at various levels (cycle threshold [Ct]). The influenza A viruses were then subtyped from swabs by using a microarray assay (Clondiag, Jena, Germany) that enabled the rapid identification of influenza virus A (H10N7). The virus was readily cultured from swabs in embryonated chicken eggs and in MDCK cell cultures. Several viral genome segments were sequenced, which enabled confirmation of the virus as LPAI A (H10N7) and performance of phylogenetic analysis. A fluorescence-based neuraminidase inhibition assay showed the isolate to be sensitive to the antiviral drugs oseltamivir and zanamivir (mean 50% inhibitory concentration ± SD 0.5 ± 0.1 nmol/L and 1.8 ± 0.3 nmol/L, respectively).

Serologic testing was conducted by using an influenza A nucleoprotein–based blocking ELISA and a subtype H10–specific hemagglutination inhibition test; results showed widespread infection in the affected flock, with 18 of 20 samples seropositive. Sampling across a 4 additional flocks on site showed that an additional 9 of 40 birds were seropositive for influenza A subtype H10. Ten days after the outbreak was confirmed, 3 previously seronegative flocks from the site were sent to an abattoir; 1 day earlier, they had passed state government clinical inspection, including inspection and examination of production and mortality records. Within a week, 7 workers at the abattoir showed signs of conjunctivitis; 2 also reported rhinorrhea and 1 a sore throat. Conjunctival swabs were collected from 6 of the workers and nose and throat swabs from all 7. Influenza A RNA was detected by PCR 4 days after abattoir exposure in conjunctival swabs from a worker who reported conjunctivitis, rhinorrhea, and sore throat (Ct 31.8) and 7 days after abattoir exposure from the nose/throat swab of another worker who reported only conjunctivitis with onset 2 days earlier (Ct 35). Partial sequence analysis of the hemagglutinin genes from both samples (GenBank accession nos. CY063325 and CY063326) confirmed the presence of influenza A subtype H10; the partial sequences were identical to the subtype H10 chicken isolate, although no virus was cultured from the workers.

The conjunctivitis and other reported symptoms among the 7 workers were mild and of short duration, and there was no evidence of seroconversion by hemagglutination inhibition or virus neutralization tests in any of the workers from whom convalescent-phase blood was collected, including the 2 with confirmed influenza A subtype H10 infection. These findings are consistent with the mild symptoms and lack of serologic evidence reported in humans after experimental infection with influenza A (H10N7), which may indicate the limited ability of the virus to multiply and stimulate a detectable immune response in humans. Other studies have reported no evidence of elevated subtype H10–specific antibody titers among poultry abattoir workers, although serologic evidence of subtype H10 infection was detected among turkey farmers in the absence of clinical symptoms. Although 4 farm staff members from the site of the initial infections reported conjunctivitis and other symptoms to health care workers, influenza was not confirmed. The abattoir workers with laboratory-confirmed influenza A subtype H10 infection handled offal and giblets in a section of the abattoir where automated evisceration usually took place; however, because of the size of the birds, evisceration was manually assisted on the day that these flocks were slaughtered.

No obvious breach of biosecurity occurred on the farm. The water supply to the farm was chlorinated town water; no large dams were on site, only small paddock dams for cattle. The sheds were birdproof and protected by additional bird netting. A feed mill supplied the feed, which was delivered into silos through blow pipes from outside the perimeter fence. Litter (wood shavings) was delivered in enclosed bales. Workers showered on the way in and out of facilities; disinfectant foot baths were placed at the entrance of each shed, and staff were required to use the separate footwear provided inside the shed. Staff were not allowed to have birds or pigs at home. During 2010, the number of wild waterfowl observed on the affected site was unusually low. Surveillance of poultry flocks within a 2-km radius of the affected farm did not detect any serologic or virologic evidence of subtype H10 infection. Ongoing surveillance of wild waterfowl in New South Wales reported influenza virus A (H10N7) in other areas in the previous year (K.E. Arzey, unpub. data); however, during 2007–2008, onsite surveillance detected no evidence of influenza A infection among wild waterfowl (G.G. Arzey, unpub. data).

Emerging Infectious Diseases
May 15, 2012

Original web page at Emerging Infectious Diseases

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Buffalo bushmeat linked to brucellosis in Botswana

Among the people of Botswana, the wild African buffalo is the burger of choice. But this bushmeat could be making consumers sick: the animals harbour a pathogen that can cause severe fever in humans. The same pathogen is also common in some populations of buffalo in the US. In 1974, researchers discovered that a bacterium from the genus Brucella, which causes brucellosis in humans, was widespread in herds of wild buffalo in Botswana. In response, the government built fences to isolate infected buffalo from domestic cattle, which can pass the disease to humans through meat, dairy products and close contact. However, although the fences are effective and the pathogen has been eradicated from livestock, brucellosis still occurs in Botswanans. To find out why, Kathleen Alexander of Virginia Tech in Blacksburg and her team sampled over 1000 large wild animals, including buffalo, in Botswana. They found that about 6 per cent still carry antibodies against Brucella, suggesting that the disease remains in these wild populations.

Alexander’s team suggests that hunting buffalo for bushmeat – both legally and illegally – may account for human cases. It is not just the hunters who risk infection: Alexander says that families will often buy bushmeat and process it together, possibly contracting the pathogen through the animal’s blood. The risk of catching brucellosis from wildlife has also been a longstanding debate in the US: the iconic Yellowstone bison have been blamed for infecting cattle with the disease, which can cause pregnant cows to abort. And in Florida, there are reports of hunters getting brucellosis from wild boar, says report co-author Jason Blackburn of the University of Florida in Gainesville. “We need to make sure we have a clear understanding of how humans are interacting with wildlife and identify alternative sources of risk,” says Blackburn. In African countries some cases of brucellosis may be misdiagnosed as malaria – the most common suspect for fever – because it may be falsely assumed only those who handle livestock risk exposure to Brucella. Although brucellosis is rarely fatal in adults and can be treated with antibiotics, it may cause abortions. And in Botswana, about 40 per cent of the urban population is HIV-positive, says Alexander. For them, even a mild infection can be very serious. Journal reference: PLoS One.

New Scientist
April 3, 2012

Original web page at New Scientist

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Chicken as reservoir for extraintestinal pathogenic Escherichia coli in humans, Canada

We previously described how retail meat, particularly chicken, might be a reservoir for extraintestinal pathogenic Escherichia coli (ExPEC) causing urinary tract infections (UTIs) in humans. To rule out retail beef and pork as potential reservoirs, we tested 320 additional E. coli isolates from these meats. Isolates from beef and pork were significantly less likely than those from chicken to be genetically related to isolates from humans with UTIs. We then tested whether the reservoir for ExPEC in humans could be food animals themselves by comparing geographically and temporally matched E. coli isolates from 475 humans with UTIs and from cecal contents of 349 slaughtered animals. We found genetic similarities between E. coli from animals in abattoirs, principally chickens, and ExPEC causing UTIs in humans. ExPEC transmission from food animals could be responsible for human infections, and chickens are the most probable reservoir. Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of community-acquired urinary tract infections (UTIs) in humans, accounting for >85% of UTIs. Each year, 6–8 million UTIs are diagnosed in the United States, and 130–175 million are diagnosed worldwide. Estimated direct health care costs related to uncomplicated UTIs in the United States are $1–$2 billion per year. UTIs also can lead to more severe illnesses, such as pyelonephritis, bacteremia, and sepsis. During the past decade, the emergence of drug-resistant E. coli has dramatically increased. As a consequence, the management of UTIs, which was previously straightforward, has become more complicated; the risks for treatment failure are higher, and the cost of UTI treatment is increasing.

In the past, extraintestinal E. coli infections have been described as sporadic infections caused by bacteria that originate from the host’s intestinal tract. However, ExPEC strains recently have been associated with possible outbreaks. Communitywide outbreaks have been described in south London (E. coli O15:K152:H1); Copenhagen (E. coli O78:H10); Calgary, Alberta, Canada (extended-spectrum β-lactamase–producing E. coli); and California, USA (trimethoprim/sulfamethoxazole–resistant E. coli). These outbreaks suggest that ExPEC can be spread to the intestinal tracts of persons in the community by a common source or vehicle.

We recently described the results of a study that characterized the genetic similarities between E. coli isolates recovered from retail meat, particularly chicken, and ExPEC in humans causing community-acquired UTIs. That study oversampled isolates from retail chicken because evidence suggested that chicken was likely to be the primary reservoir of ExPEC in humans. To exclude the possibility that isolates from other retail meat sources (beef and pork) might also be genetically related to UTI isolates from humans, we first aimed to characterize additional E. coli isolates recovered from retail beef and pork sources. These new isolates from retail meat were added to the preexisting collection of retail meat isolates and compared with the same UTI isolates from humans. Second, we aimed to determine whether transmission was primarily human to human through food or whether an animal source was involved. In the case of human-to-human transmission through food, E. coli strains from humans would be introduced during the meat preparation process by food handlers. In the case of an animal source, the E. coli would derive from the cecal content of the animal itself, and contamination would occur during the slaughtering process. On the basis of previous findings, we hypothesized that a food animal reservoir exits for ExPEC that cause UTIs in humans and that chicken is the primary source. To evaluate this hypothesis, we analyzed isolates from animals entering the food chain. E. coli isolates recovered from the cecal contents of slaughtered food animals (beef cattle, chickens, and pigs) were compared with the preexisting geographically and temporally matched collection of isolates from humans with UTIs.

Emerging Infectious Diseases
March 20, 2012

Original web page at Emerging Infectious Diseases

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Organic meat not free of drug-resistant bacteria

If you’re paying premium prices for pesticide- and antibiotic-free meat, you might expect that it’s also free of antibiotic-resistant bacteria. Not so, according to a new study. The prevalence of one of the world’s most dangerous drug-resistant microbe strains is similar in retail pork products labeled “raised without antibiotics” and in meat from conventionally raised pigs, researchers have found. Methicillin-resistant Staphylococcus aureus (MRSA), a drug-resistant form of the normally harmless S. aureus bacterium, kills 18,000 people in the United States every year and sickens 76,000 more. The majority of cases are linked to a hospital stay, where the combination of other sick people and surgical procedures puts patients at risk. But transmission also can happen in schools, jails, and locker rooms (and an estimated 1.5% of Americans carry MRSA in their noses). All of this has led to a growing concern about antibiotic use in agriculture, which may be creating a reservoir of drug-resistant organisms in billions of food animals around the world. Tara Smith, an epidemiologist at the University of Iowa College of Public Health in Iowa City who studies the movement of staph bacteria between animals and people, wondered whether meat products might be another mode of transmission. For the new study, published this month in PLoS ONE, she and colleagues bought a variety of pork products—395 packages in all—from 36 different stores in two big pig farming states, Iowa and Minnesota, and one of the most densely populated, New Jersey.

In the laboratory, the team mixed meat samples “vigorously” with a bacterial growth medium and allowed any microbes present to grow. MRSA, which appears as mauve-colored colonies on agar plates, was genetically typed and tested for antibiotic susceptibility. The researchers found that 64.8% of the samples were positive for staph bacteria and 6.6% were positive for MRSA. Rates of contamination were similar for conventionally raised pigs (19 of 300 samples) and those labeled antibiotic-free (seven of 95 samples). Results of genetic typing identified several well-known strains, including the so-called livestock-associated MRSA (ST398) as well as common human strains; all were found in conventional and antibiotic-free meat. Smith says she was surprised by the results. In a related investigation, which has not been published, her group tested pigs living on farms and found that antibiotic-free pigs were free from MRSA, whereas the resistant bug is often found on conventional pig farms. The study reveals an important data point on the path from farm to fork, yet the source of the MRSA on meat products is unknown, Smith says. “It’s difficult to figure out.” Transmission of resistant bugs might occur between antibiotic-using and antibiotic-free operations, especially if they’re near each other, or it could come from farm workers themselves. Another possibility is that contamination occurs at processing plants. “Processing plants are supposed to be cleaned between conventional and organic animals,” she says. “But how well does that actually happen?”

In another recent study, researchers from Purdue University in West Lafayette, Indiana, found that beef products from conventionally raised and grass-fed animals were equally likely to be contaminated by antibiotic-resistant Escherichia coli. In a second study by the same group, poultry products labeled “no antibiotics added” carried antibiotic-resistant E. coli and Enterococcus (another bacteria that causes invasive disease in humans), although the microbes were less prevalent than on conventionally raised birds. “The real question is, where is it coming from, on the farm or post-farm?” says Paul Ebner, a food safety expert who led the Purdue studies. And the biggest question of all, he says, “Is it impacting human health?” “There’s a tremendous amount of interest in this issue—feeding antibiotics to food animals,” says Ellen Silbergeld, an expert on health and environmental impacts of industrial food animal production at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. “Thus, determining when amending that practice makes a difference is important.” “The definitive study would take every bacterium and follow that along until it gets in humans—from food supply to causing a certain disease,” Smith says. “It would be a huge and costly study that no one’s going to do, but that’s what the meat producers say is missing.” Meanwhile, Smith says she will continue her investigations of MRSA, one potential transmission point at a time.

ScienceNow
February 21, 2012

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Raw milk is a dangerous raw deal for farmers and consumers

On Feb. 2, health officials in Pennsylvania said at least 35 people in four states were struck with a bacterial infection after drinking unpasteurized “raw” milk, the same day a New Jersey legislative committee approved a bill to allow raw milk sales in that state. Martin Wiedmann and Rob Ralyea, Cornell University researchers and experts on food safety, comment and the danger presented to farmers and consumers by the raw milk movement. Rob Ralyea is a senior extension associate with the Milk Quality Improvement Program in the Department of Food Science. On Feb. 2, he testified before the New Jersey State Assembly’s Agriculture and Natural Resources Committee about the dangers of raw milk. “While some people think allowing sales of raw milk is in the best interest of the farmers, it’s inherently not in these situations. “Farms risk losing a lot, including the farm, for the few dollars more they get when selling raw milk. There is currently a lawsuit in Washington for $2.4 million as a result of raw milk illness, so there is a liability when an illness can be traced to a farm. We wear seatbelts because they have been proven to reduce injuries and deaths in auto accidents. Pasteurization does the same thing as it relates to public health and consuming milk.

“A proven public health mechanism is completely removed in this case and anything can happen, as is illustrated once again in Pennsylvania.” Martin Wiedmann is a professor of food science and a doctor of veterinary medicine and also directs the Cornell Milk Quality Improvement Program. Wiedmann’s research focuses on the transmission of bacterial and food-borne diseases and dairy food safety and quality. “Raw milk represents a considerable risk for consumers, who may experience severe food-borne diseases that can be transmitted through raw milk – including diarrhea, brain infections, abortions and chronic neurological diseases. “Farmers who sell raw milk also take a considerable risk – if raw milk sold by a given farm causes human disease, farmers are likely to be sued by lawyers specializing in food-borne disease litigation and may have to pay millions of dollars to disease victims. “This outbreak serves as another reminder of the dangers of selling and consuming raw milk.”

Science Daily
February 21, 2012

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High levels of MRSA bacteria in U.S. retail meat products

Retail pork products in the U.S. have a higher prevalence of methicillin-resistant Staphylococcus aureus bacteria (MRSA) than previously identified, according to new research by the University of Iowa College of Public Health and the Institute for Agriculture and Trade Policy. MRSA can occur in the environment and in raw meat products, and is estimated to cause around 185,000 cases of food poisoning each year. The bacteria can also cause serious, life-threatening infections of the bloodstream, skin, lungs and other organs. MRSA is resistant to a number of antibiotics. The study, published Jan. 19 in the online science journal PLoS ONE, represents the largest sampling of raw meat products for MRSA contamination to date in the U.S. The researchers collected 395 raw pork samples from 36 stores in Iowa, Minnesota and New Jersey. Of these samples, 26 — or about 7 percent — carried MRSA. “This study shows that the meat we buy in our grocery stores has a higher prevalence of staph than we originally thought,” says lead study author Tara Smith, Ph.D., interim director of the UI Center for Emerging and Infectious Diseases and assistant professor of epidemiology. “With this knowledge, we can start to recommend safer ways to handle raw meat products to make it safer for the consumer.”

The study also found no significant difference in MRSA contamination between conventional pork products and those raised without antibiotics or antibiotic growth promotants. “We were surprised to see no significant difference in antibiotic-free and conventionally produced pork,” Smith says. “Though it’s possible that this finding has more to do with the handling of the raw meat at the plant than the way the animals were raised, it’s certainly worth exploring further.”

Science Daily
February 7, 2012

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Evidence supports ban on growth promotion use of antibiotics in farming

In a review study, researchers from Tufts University School of Medicine zero in on the controversial, non-therapeutic use of antibiotics in food animals and fish farming as a cause of antibiotic resistance. They report that the preponderance of evidence argues for stricter regulation of the practice. Stuart Levy, an expert in antibiotic resistance, notes that a guiding tenet of public health, the precautionary principle, requires that steps be taken to avoid harm. “The United States lags behind its European counterparts in establishing a ban on the use of antibiotics for growth promotion. For years it was believed that giving low-dose antibiotics via feed to promote growth in cows, swine, chickens and the use of antibiotics in fish farming had no negative consequences. Today, there is overwhelming evidence that non-therapeutic use of antibiotics contributes to antibiotic resistance, even if we do not understand all the mechanisms in the genetic transmission chain,” says Levy, MD, professor of molecular biology and microbiology and director of the Center for Adaptation Genetics and Drug Resistance at Tufts University School of Medicine.

For the past 70 years, humans have relied on antibiotics to combat bacterial infections such as streptococcus, meningitis, tuberculosis and urinary tract infections. The misuse and overuse of antibiotics, however, has contributed to antibiotic resistance, making antibiotics less effective at saving lives. Levy and co-author Bonnie Marshall summarize and synthesize the findings of a large number of studies assessing the link between antibiotic resistance and the use of non-therapeutic antibiotics in livestock and fish farming. Highlights include the following.

•According to estimates, antibiotics are eight times more likely to be used for non-therapeutic purposes than for treating a sick animal. Current practices set the stage for the rapid spread of antibiotic-resistant bacteria
•The long-term administration of antibiotics in animal feed creates an optimal environment for antibiotic resistance genes to multiply. Essentially, treated animals become “factories” for the production and distribution of antibiotic-resistant bacteria such as Salmonella and Methicillin-resistant Staphylococcus aureus (MRSA), a troubling infection that is resistant to common antibiotics.
•Bacteria can transfer antibiotic resistance to other bacteria, and multiple different resistance genes can be linked together in this process. Thus, even if farmers turn to antibiotics that are not commonly used to treat people, these drugs — given over long periods of time — can also promote resistance. Several studies demonstrated that antibiotic-resistant bacteria can easily spread from animals to people in close contact with animals, such as veterinarians, slaughterhouse workers, farmers, and the families of farmers.
•As much as 90 percent of antibiotics given to livestock are excreted into the environment. Resistance spreads directly by contact and indirectly through the food chain, water, air, and manured and sludge-fertilized soils.
•The broad use of antibiotics in fish food in farm fishing, particularly overseas, leads to leaching where it can be washed to other sites, exposing wild fish to trace amounts of antibiotics.
•According to the Centers for Disease Control and Prevention, antibiotic-resistant infections cause longer and more expensive hospital stays, and greater risk of death. Each year in the US antibiotic-resistant infections result in $20 billion in additional health care costs and $8 million in costs in additional hospital days. If antibiotics are ineffective, patients may end up paying more in search of alternative drugs, and enduring a wider range of side effects.
Bans on the use of non-therapeutic antibiotics are effective in diminishing antibiotic resistance
•Bans in several European countries have led to decreases in antibiotic resistance. Bans in Denmark and Germany have not only decreased the presence of antibiotic-resistant bacteria in farm animals, they have decreased the presence of these bacteria in humans.
•Alternative farming practices such as reducing animal crowding, improving hygiene, and improving use of vaccines have been shown to compensate for some of the growth benefits conferred by non-therapeutic antibiotics.

Levy and Marshall also highlight areas of study that may improve our understanding of the link between antibiotic use in animals and the spread of antibiotic-resistant bacteria. Modern genetic techniques are helping, they report, but there are still gaps in our understanding at each stage of the transmission chain. “Aquaculture, or fish farming, has been relatively understudied, yet water is a prime medium for the spread of antibiotic-resistant bacteria,” says first author Bonnie Marshall, MA, MT (medical technology), senior research associate in the Levy laboratory at Tufts University School of Medicine. “While the use of non-therapeutic antibiotics remains contentious, the evidence is strong enough to merit precaution. Antibiotics save lives. When infections become resistant to primary antibiotics, and alternative antibiotics must be used, health care costs increase. As more infections become more resistant to more antibiotics, we run the risk of losing more of our arsenal of antibiotics, resulting in needless deaths. It’s important to consider what we stand to gain versus what we stand to lose,” concludes Levy. The Food & Drug Administration (FDA) has already taken some steps toward stricter regulation of non-therapeutic antibiotic use, acknowledging that the practice is in conflict with protecting the public health and proposing measures to limit the use of these drugs in animals. Levy and his colleagues in the field of infectious disease have called for antibiotics to be classified by the FDA as “societal drugs,” establishing specific regulations to protect the efficacy of the drugs.

Science Daily
December 13, 2011

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Expert calls for change in trans fat labelling

Not all trans fats are created equal and it’s time for nutritional labels to reflect that reality, says a University of Alberta nutrition expert. According to a scientific review conducted by Spencer Proctor, along with Canadian and international colleagues, natural trans fats produced by ruminant animals such as dairy and beef cattle are not detrimental to health. In fact, they show significant positive health effects and some evidence even links these natural trans fats to reduced risk of cardiovascular disease and cancer. According to the review, naturally occurring trans fat has a different fatty acid profile than industrial trans fat, which contributes to its different physiological effects. Ruminant trans fat is naturally occurring and found in meat and dairy foods, while industrial produced trans fat is a component of partially hydrogenated vegetable oils, which have been strongly associated with cholesterol and coronary heart disease. Consumers are bombarded on a regular basis about what they should and shouldn’t eat. Quite often fat is the primary target of what to avoid and trans fats in particular have a negative reputation. “A change in how trans fat information is presented on nutrition labels would be a huge step forward,” says Proctor, a researcher in the Department of Agricultural, Food and Nutritional Science who is director of the Metabolic and Cardiovascular Diseases Laboratory at the U of A. “Right now, in Canada and the U.S., a substantial portion of natural trans fats content is included in the nutrition label trans fats calculation, which is misleading for the consumer. We need a reset in our approach to reflect what the new science is telling us.”

Spencer adds that in some European countries, natural trans fat is not included in the nutrition label calculation. Another approach may be to have separate listings for industrial trans fats and natural trans fats. Researchers evaluated an evidence base from numerous studies in the review. Based on the promising findings to date, plans for new studies are gaining momentum to further investigate the health implications of natural ruminant-derived trans fats. One leading scientific program headed by Proctor was recently approved for a $1 million research grant from the Alberta Livestock and Meat Agency to further this line of study over the next several years. “With industry, the science community, regulators and other important groups in this area working together, we can continue to make strides to help the public better understand the health implications of natural ruminant trans fats,” says Proctor.

Science Daily
September 20, 2011

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‘Goat Plague’ threat to global food security and economy must be tackled, experts warn

“Goat plague,” or peste des petits ruminants (PPR), is threatening global food security and poverty alleviation in the developing world, say leading veterinarians and animal health experts in this week’s Veterinary Record. They call on the UN Food and Agricultural Organisation (FAO) and the World Organisation for Animal Health (OIE) to turn their attention now to ridding the world of the PPR virus, which carries a very high risk of death among infected animals. The call follows the formal announcement this week by the FAO that a related virus, rinderpest, better known as “cattle plague,” has now been eradicated around the globe. In an editorial, senior vets, all of whom were variously involved in the global rinderpest eradication campaign, say that getting rid of that virus has had far reaching effects. “What is not generally appreciated is that the eradication of rinderpest has yielded benefits that surpass virtually every other development programme in agriculture, and will continue to do so in future,” they write. They cite the case of Chad, where between 1963 and 2002, every dollar spent on rinderpest eradication made a return of at least $US16.

Now the world must focus on achieving the same for PPR, which is endemic in most of sub Saharan Africa “as well as a swathe of countries from Turkey through the Middle East to south Asia,” they say. The virus has also recently been reported in North Africa, central Asia, and China. It’s important to control the infection because it spreads quickly through goat herds and sheep flocks, decimating their numbers, and taking a terrible financial toll on the farmers and families who depend on these animals for their livelihoods, say the authors. And it has also spread to wildlife species, many of which are endangered or threatened. “Because poorer people are more likely to keep small ruminants than cattle, women and children tend to have more access and control over them, PPR control and eradication would be both pro-poor and pro-women and children. It fits many development objectives for nutrition, food security and poverty alleviation,” they write. “We believe that a global programme for the total eradication of PPR should be established as an international undertaking without delay,” they declare. “Given support from governments, international organisations, and funding agencies, we believe that another great success could be achieved within a 10 year time frame with concerted international effort,” they suggest.

In a review published in the same issue, senior international vets, including from the Institute for Animal Health in Pirbright, Surrey, document the history of the infection and explain the scientific basis for eradication of the virus. “Although PPR has not yet been seen in the UK, and is currently absent from most European countries, it is without doubt the fastest growing and potentially the most economically important disease of sheep and goats anywhere in the developing world,” they write. They go on to say that there has been a reluctance to tackle the issue because sheep and goats are considered to be of lesser economic value than cattle, and their shorter working lives mean that it would cost more to eradicate PPR. But they warn: “The ever advancing spread of PPR has made the economic impact of the disease, and consequently the benefits of its eradication, much greater. The imperative for coordinated action is therefore much stronger.”

Science Daily
July 12, 2011

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US meat and poultry is widely contaminated with drug-resistant Staphylococccus aureus bacteria

Drug-resistant strains of Staphylococcus aureus, a bacteria linked to a wide range of human diseases, are present in meat and poultry from U.S. grocery stores at unexpectedly high rates, according to a nationwide study by the Translational Genomics Research Institute (TGen) Nearly half of the meat and poultry samples — 47 percent — were contaminated with S. aureus, and more than half of those bacteria — 52 percent — were resistant to at least three classes of antibiotics, according to the study published April 15 in the journal Clinical Infectious Diseases. This is the first national assessment of antibiotic resistant S. aureus in the U.S. food supply. And, DNA testing suggests that the food animals themselves were the major source of contamination.

Although Staph should be killed with proper cooking, it may still pose a risk to consumers through improper food handling and cross-contamination in the kitchen. Researchers collected and analyzed 136 samples — covering 80 brands — of beef, chicken, pork and turkey from 26 retail grocery stores in five U.S. cities: Los Angeles, Chicago, Fort Lauderdale, Flagstaff and Washington, D.C. “For the first time, we know how much of our meat and poultry is contaminated with antibiotic-resistant Staph, and it is substantial,” said Lance B. Price, Ph.D., senior author of the study and Director of TGen’s Center for Food Microbiology and Environmental Health. “The fact that drug-resistant S. aureus was so prevalent, and likely came from the food animals themselves, is troubling, and demands attention to how antibiotics are used in food-animal production today,” Dr. Price said. Densely-stocked industrial farms, where food animals are steadily fed low doses of antibiotics, are ideal breeding grounds for drug-resistant bacteria that move from animals to humans, the report says. “Antibiotics are the most important drugs that we have to treat Staph infections; but when Staph are resistant to three, four, five or even nine different antibiotics — like we saw in this study — that leaves physicians few options,” Dr. Price said.

“The emergence of antibiotic-resistant bacteria — including Staph — remains a major challenge in clinical medicine,” said Paul S. Keim, Ph.D., Director of TGen’s Pathogen Genomics Division and Director of the Center for Microbial Genetics and Genomics at Northern Arizona University (NAU). “This study shows that much of our meat and poultry is contaminated with multidrug-resistant Staph. Now we need to determine what this means in terms of risk to the consumer,” said Dr. Keim, a co-author of the paper. The U.S. government routinely surveys retail meat and poultry for four types of drug-resistant bacteria, but S. aureus is not among them. The paper suggests that a more comprehensive inspection program is needed. S. aureus can cause a range of illnesses from minor skin infections to life-threatening diseases, such as pneumonia, endocarditis and sepsis.

Science Daily
May 3, 2011

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Foodborne illness acquired in the United States—major pathogens

Estimates of foodborne illness can be used to direct food safety policy and interventions. We used data from active and passive surveillance and other sources to estimate that each year 31 major pathogens acquired in the United States caused 9.4 million episodes of foodborne illness (90% credible interval [CrI] 6.6–12.7 million), 55,961 hospitalizations (90% CrI 39,534–75,741), and 1,351 deaths (90% CrI 712–2,268). Most (58%) illnesses were caused by norovirus, followed by nontyphoidal Salmonella spp. (11%), Clostridium perfringens (10%), and Campylobacter spp. (9%). Leading causes of hospitalization were nontyphoidal Salmonella spp. (35%), norovirus (26%), Campylobacter spp. (15%), and Toxoplasma gondii (8%). Leading causes of death were nontyphoidal Salmonella spp. (28%), T. gondii (24%), Listeria monocytogenes (19%), and norovirus (11%). These estimates cannot be compared with prior (1999) estimates to assess trends because different methods were used. Additional data and more refined methods can improve future estimates.

Estimates of the overall number of episodes of foodborne illness are helpful for allocating resources and prioritizing interventions. However, arriving at these estimates is challenging because food may become contaminated by many agents (e.g., a variety of bacteria, viruses, parasites, and chemicals), transmission can occur by nonfood mechanisms (e.g., contact with animals or consumption of contaminated water), the proportion of disease transmitted by food differs by pathogen and by host factors (e.g. age and immunity), and only a small proportion of illnesses are confirmed by laboratory testing and reported to public health agencies. Laboratory-based surveillance provides crucial information for assessing foodborne disease trends. However, because only a small proportion of illnesses are diagnosed and reported, periodic assessments of total episodes of illness are also needed. (Hereafter, episodes of illness are referred to as illnesses.) Several countries have conducted prospective population-based or cross-sectional studies to supplement surveillance and estimate the overall number of foodborne illnesses. In 2007, the World Health Organization launched an initiative to estimate the global burden of foodborne diseases.

Emerging Infectious Diseases
January 24, 2011

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Shellfish safer to eat thanks to breakthrough by Queen’s scientists

New technology to make shellfish safer to eat has been pioneered by scientists at Queen’s University Belfast. The new test, developed at Queen’s Institute for Agri-Food and Land Use, not only ensures shellfish are free of toxins before they reach the food chain but is likely to revolutionise the global fishing industry. While the current process for monitoring potentially dangerous toxins in shellfish takes up to two days, the new test slashes the testing time to just 30 minutes using new biosensor technology and provides a much more reliable result. The test detects paralytic shellfish poisons, which paralyse anyone who consumes them and kills around 25 per cent people who are poisoned. Leading the project is Professor Chris Elliott, Director of the Institute of Agri-Food and Land Use at Queen’s School of Biological Sciences, who said: “Toxins secreted by algae, and which concentrate in shellfish, are a major hazard to consumers and can bring huge economic losses to the aquaculture industry.

“While the existence of these toxins has been known for some time, there have been major concerns about the effectiveness of tests used to detect them. There is also growing evidence that climate change is causing many more toxic episodes across the world, resulting in the closure of affected shellfish beds. “The new test, developed at Queen’s, is much quicker and more reliable than existing methods. It works by using unique ‘detector proteins’ to seek out minute amounts of toxins present in mussels, oysters, cockles and scallops. “The test will not only make shellfish safer to eat, but it will also have a significant impact on global aquaculture industries as they struggle to deal with the rising problems of toxins caused by climate change. “The test has been developed as part of a €10 million (Euro) BioCop research project led by Queen’s and involving 32 international research partners and the European Commission.

“We have also signed a substantial contract with the UK-based company Neogen Europe to commercialise the idea. This will be the third such aquaculture product developed by Queen’s and Neogen Europe, helping the company to develop its unique portfolio of rapid food safety tests and reinforcing Queen’s reputation as a global leader in this area.” Research at Queen’s will also be aided by a $500,000 (US dollars) grant from The American Food and Drugs Administration (FDA) to further develop the test in the USA so it can be conducted in laboratories and on boats as soon as the shellfish are caught, and will help drastically cut the time taken to get the catch from fishing nets to supermarket shelves.

EurekAlert! Medicine
January 24, 2011

Original web page at EurekAlert! Medicine

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Stricter testing for federal ground beef program may not lead to safer meat

A new National Research Council report finds no scientific basis that more stringent testing of meat purchased through the government’s ground beef purchase program and distributed to various federal food and nutrition programs — including the National School Lunch Program — would lead to safer meat. The U.S. Department of Agriculture’s Agricultural Marketing Service (AMS) buys ground beef from suppliers who must meet mandatory process, quality, traceback, and handling controls as well as comply with strict limitations on the amounts of bacteria in the meat, such as E. coli and salmonella. AMS then distributes the ground beef to federal programs, including food banks, emergency feeding programs, Indian reservations, and disaster relief agencies. In its assessment of AMS’s ground beef purchase program, the committee that wrote the report said validated cooking processes provide greater assurance of ground beef’s safety than would additional testing for pathogens. Testing alone cannot guarantee the complete absence of pathogens because of statistical implications associated with how beef is sampled during testing.

The committee’s analysis of the number of illnesses since 1998 linked with AMS ground beef provided to schools suggests that outbreaks were rare events before AMS requirements became more stringent in February, implying that controls already in place were appropriate for protecting public health. For instance, no recorded outbreaks of E. coli or salmonella associated with AMS ground beef have occurred in more than a decade. Prevention of future outbreaks will depend on eliminating contamination during production and ensuring meat is properly handled, stored, and cooked before it is served, the committee emphasized. As part of its review, the committee also attempted to compare the AMS specifications with those of large industry purchasers of ground beef. Among purchasers, the committee found considerable differences in testing and safety standards and suspected that the intended use of the ground beef could account for the variations. For example, all raw AMS ground beef is distributed in frozen form, but distributors of fresh meat products may require different standards designed to improve shelf life. While AMS safety requirements appear comparable to or more demanding than those of commercial companies on the surface, the lack of information detailing the science used for corporate specifications prevented the committee from making direct comparisons.

Additional specifications under the AMS program call for testing food samples and surfaces at the suppliers to look for the presence of “indicator” microorganisms that could denote unsanitary conditions, improper hygiene and processing techniques, post-processing contamination, and storage-temperature abuse. Although a reduction in the number of indicator organisms implies a reduction in the amount of pathogens, the presence of an indicator does not guarantee that a pathogen is also present, the committee said. For an indicator to be an effective predictor of a pathogen’s presence, a statistical association needs to be established. Therefore, the committee recommended that AMS assess the usefulness of its microbiological data as a scientific basis for testing for indicators. “The report encourages AMS to strengthen its established specifications and requirements for ground beef by utilizing a transparent and clearly defined science-based process,” said Gary Acuff, chair of the committee and professor and director of the Center for Food Safety at Texas A&M University, College Station.

In addition, the report says that some of the requirements were founded on expert opinion and industry practices where the scientific basis was unclear. The committee recommended that AMS base their requirements on standards supported by the International Commission on Microbiological Safety of Foods, the Codex Alimentarius Commission, and the Research Council report An Evaluation of the Role of Microbiological Criteria for Foods and Food Ingredients. It also suggested that AMS analyze data from the suppliers’ bacterial testing to evaluate the safety requirements over time and use statistical methods to set testing sample and lot sizes. Overall, AMS should develop a systematic, transparent, and auditable system for modifying, reviewing, updating, and justifying purchasing specifications.

The committee noted that maintaining people’s confidence in the safety, quality, and nutritional value of the products AMS purchases is especially important because of the nature of the program and the clientele it serves. Though AMS may find it appropriate to adopt and implement conservative standards and requirements that both protect public health and provide the best quality product, it needs to consider the potential unintended consequences of increased testing and product requirements, the committee said. Additional testing would likely increase costs to producers, which could impact the purchase price of ground beef available through the program. Under such circumstances, schools might decide to buy their ground beef on the open market at a lower cost.

Science Daily
December 21, 2010

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Feed likely source of Salmonella contamination on pig farms

Commercial feed appears to be a source of Salmonella contamination in commercial swine production units, according to a paper in the November 2010 issue of the journal Applied and Environmental Microbiology. Moreover, nearly half of isolates found in pigs were multidrug resistant. The findings suggest that pork could be a source of human infection. They also strongly question the conventional wisdom that processed feed is not a source of contamination. Heat treatment during processing has been thought to kill any bacterial contaminants. The research team, led by Wondwossen A. Gebreyes of the College of Veterinary Medicine, The Ohio State University, tested samples collected from feed bins prior to exposure to the barn environment, as well as fecal samples and environmental samples from the barns. They found contaminated feed in eight of 36 barns tested, with a sample prevalence of 3.6%. These isolates fell into five different genotypes. In four of the five cases, they found that fecal samples they tested from a given barn and time point matched the feed samples from the same barn and time period, suggesting that the feed was indeed the contamination source.

“These genotypic clusters also shared similar antimicrobial resistance profiles and serogroups,” says Gebreyes. That provides additional support for both the genotypic findings, confirming the hypothesis that the contamination originated in the feed. Gebreyes says that the source of feed contamination is most likely the feed ingredients, but that feed could be contaminated via handling, after processing. “Although we cannot ascertain 100% that the feed was the source of contamination that was transmitted to the fecal samples, the findings strongly imply that fact,” says Gebreyes. “The other alternative is that the feed was contaminated after it was introduced into the barn. Regardless, the findings strongly imply that salmonella can be maintained and easily disseminated in a population of food animals.”

Science Daily
December 7, 2010

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Salmonella test makes food safer, reduce recalls

Earlier this year, an outbreak of salmonella caused by infected eggs resulted in thousands of illnesses before a costly recall could be implemented. Now, University of Missouri researchers have created a new test for salmonella in poultry and eggs that will produce faster and more accurate results than most currently available tests. The new test could have prevented the contaminated eggs from being shipped to stores. Processors and consumers will benefit from the speed and sensitivity of the new test’s results,” said Azlin Mustapha, associate professor of food science in the College of Agriculture, Food and Natural Resources. “This will keep companies from shipping contaminated products, and thus, keep salmonella infected products out of consumers’ hands.” Salmonella is the most common cause of food poisoning in the United States, according to the Centers for Disease Control. Salmonellosis, the disease caused by salmonella, causes diarrhea, vomiting, fever, abdominal cramps and, in severe cases, death. Mustapha said salmonella testing in poultry is important because it persists in birds’ spleens and reproductive tracts. An infected bird passes the infection on to all of its eggs. The most commonly used testing method for salmonella can take up to five days to produce results. Mustapha’s research allows scientists to use a process, known as polymerase chain reaction (PCR), which can cut testing time to as little as five to 12 hours. PCR-based testing methods for salmonella have been available for use by the food industry for years, but current methods often produce false-positive results because they do not differentiate between live and dead salmonella, thus skewing the accuracy of the test. Only live salmonella cells trigger salmonellosis.

Mustapha modified the PCR test by adding a dye to the test sample. The dye is absorbed by dead salmonella cells; thus, the PCR test can ignore the dead cells. Mustapha’s modification lets food scientists use the PCR test to capitalize on its speed, selectivity and sensitivity, but avoid false-positive tests by differentiating between dead and live cells. The reduced testing time would enable companies to have accurate test results before a product is shipped. With current tests, food could be in stores before salmonella test results are available. This new technology will enable companies to avoid costly recalls and keep consumers safe.

Science Daily
December 7, 2010

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Can naturally raised beef find its place in the industry?

As consumer demand for naturally raised beef continues to increase, researchers at the University of Illinois have discovered that naturally raised beef can be produced effectively for this niche market as long as a substantial premium is offered to cover additional production and transportation costs. Naturally raised beef is produced without hormones or antibiotics, whereas traditional systems take advantage of technologies the industry offers such as ionophores like Rumensin® to improve feed efficiency and implants to improve gain and efficiency. “Producers are asking many questions about the value of natural programs and the premiums needed to remain profitable,” said Dan Faulkner, U of I professor of animal sciences. “Our goal was to find out the costs involved in natural systems focused on producing environmentally friendly, locally raised beef.” Researchers studied the effects of finishing management (confinement versus pasture) and production system (traditional versus naturally raised) on performance, carcass and economic characteristics in a group of early weaned Angus x Simmental steer calves at the Dixon Springs Agricultural Center in Simpson, Ill. The calves were fed on fescue pastures or confinement feedlots.

The study revealed that naturally raised steers can be produced effectively in either confinement or with a pasture finishing system, but they require a substantial premium of $110 with today’s feed prices to justify the costs and returns. Faulkner said that pasture finishing is $35 more profitable than confinement feeding using current feed prices, making it an attractive option for producers interested in raising locker beef for local markets with either natural or traditional production systems. “I think this information will benefit smaller operations that would like to pursue a naturally raised market in a pasture finishing system, but may not be able to use a traditional confinement system,” Faulkner said. In addition, naturally raised beef in either pasture or confinement settings resulted in beef with higher quality grades. “There continues to be more interest in naturally raised beef because organic beef standards are so high,” Faulkner added. “We need to increase consumer education efforts because naturally raised beef is actually what many consumers are looking for these days.”

Both organic and naturally raised steers do not receive hormones or antibiotics. The major difference between naturally raised beef and organic beef is that organic beef comes from cattle that are raised on organic pastures that have not been treated with chemicals or chemical fertilizers. In addition, these cattle can only be fed organic certified feeds. Faulkner also differentiated pasture-fed beef from grass-fed beef. “Grass-fed cattle cannot be fed any concentrate – they can only receive roughage,” Faulkner said. “And that roughage must meet strict guidelines set by the USDA. On the other hand, pasture-fed cattle have access to a finishing diet and pasture.” Pasture-fed cattle have carcass and meat characteristics that are the same as traditionally finished cattle, he added. The meat characteristics of grass-fed cattle are quite different than the average consumer is used to eating. Faulkner said naturally raised beef, regardless of finishing management, is a niche market that has great potential if consumers will pay premium prices. “As producers, we need to be responsive to consumer demand,” he said. “Currently, naturally raised beef is a very small percentage of the market. But it is a market that is growing at several hundred percent a year, and has been identified as a niche that consumers are very interested in.”

eBioNews.com
November 9, 2010

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New method for detecting Clostridium Botulinum spores

The Institute of Food Research has collaborated in the development of a new method for detecting spores of non-proteolytic Clostridium botulinum. This bacterium is the major health hazard associated with refrigerated convenience foods, and these developments give the food industry and regulators more quantitative information on which to base the procedures that ensure food safety. Botulism is a rare but deadly form of food poisoning that can be caused by consuming tiny quantities of botulinum neurotoxin. The botulinum neurotoxin is the most potent toxin known (just 30ng of neurotoxin is sufficient to cause illness and even death), and the consumption of as little as 0.01g of food in which C. botulinum has grown can result in botulism. The majority of cases of foodborne botulism are caused by two bacteria known as non-proteolytic C. botulinum and proteolytic C. botulinum. A major difference between these two bacteria is that non-proteolytic C. botulinum is able to grow and produce toxin at 3°C, whilst proteolytic C. botulinum will not grow at temperatures less than 12°C. This ability to grow at form toxin at refrigeration temperatures makes non-proteolytic C. botulinum a major hazard in minimally heated refrigerated foods, such as chilled ready meals.

The production incorporates practices and risk assessments based on the latest scientific information, such as spore heat resistance, growth properties of non-proteolytic C. botulinum, and the incidence of these spores in food. The new method of detecting non-proteolytic C. botulinum is providing high quality information on the incidence of spores in food. An important feature of the new method is that it is specific, and enumerates only non-proteolytic C. botulinum spores. Some previous techniques were not optimised to distinguish between non-proteolytic C. botulinum and proteolytic C. botulinum. The new method is very sensitive with a low detection limit that has been achieved by the use of a selective enrichment and large test samples, and importantly this has been confirmed using carefully structured control samples. The robust method was developed as a collaboration between the Nestlé Research Centre, Switzerland and IFR, an institute of the Biotechnology and Biological Sciences Research Council (BBSRC) and is designed to provide the data the food industry needs for quantitative microbial risk analysis and the implementation of food safety objectives. This allows the total risk from spores of non-proteolytic C. botulinum in the final meal to be calculated. Modelling the risk of this total spore count rising above safe levels and the frequency that this event occurs will allow the management and control of the process with more accountability.

Science Daily
October 26, 2010

Original web page at Science Daily

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Turkey genome sequenced more than 90 percent, including sex chromosomes ‘Z’ and ‘W’

An international consortium of researchers has completed the majority of the genome sequence of the domesticated turkey, thanks in part to the efforts of Virginia Tech faculty members. The research team reports the results in the journal PLoS Biology, published by the Public Library of Science. “To date, more than 90 percent of the domesticated turkey genome has been sequenced and assembled,” said Rami Dalloul, assistant professor of animal and poultry sciences in Virginia Tech’s College of Agriculture and Life Sciences. The majority of data are derived from the 10 largest chromosomes, called macrochromosomes, and researchers in the consortium are still searching for the best route to sequence the remaining microchromosomes. “We have already described thousands of genes previously unknown to avian scientists,” Dalloul said. Also of interest are the sequences of the sex chromosomes “Z” and “W,” which were poorly covered in the past.

In 2008, the research consortium set out to map the genetic blueprint for the domesticated turkey, the fourth-most popular choice of meat in the United States. The following year, Virginia Tech and the University of Minnesota received a two-year, $900,000 grant from the U.S. Department of Agriculture to complete the genome sequence, which promises new data for avian researchers and, ultimately, a better quality product for turkey producers and consumers. “In the short term, the genome sequence will provide scientists with knowledge of specific genes that are important in meat yield and quality, health and disease resistance, fertility, and reproduction,” Dalloul said. “For example, we don’t always know the mechanism for how host-pathogen interactions work. The genome sequence will allow us to better understand this process, which will in turn give us a better understanding of disease prevention and treatment.” According to Dalloul, the genome sequence will have long-term benefits for turkey producers as well. “Poultry producers may be able to use the knowledge we gain from the genome sequence to grow turkeys faster and healthier, and if they can produce the same size bird in a shorter period of time, they can also save money,” he said. An improved understanding of genetic variation in this species and in breeding populations will also lead to development of new tools that producers can use to breed turkeys that have desirable texture, flavor, and leanness, which will directly impact consumer products.

In addition, the genome sequence may have applications in the biomedical field. Ed Smith, professor of animal and poultry sciences at Virginia Tech, is investigating an avian condition similar to dilated cardiomyopathy in humans. Other consortium members — Roger Coulombe at Utah State University and Kent Reed at the University of Minnesota — are studying the effects that aflatoxins have on turkeys. Aflatoxins are naturally occurring carcinogenic chemicals produced by fungi that suppress the immune system. The domesticated turkey is the most aflatoxin-susceptible species known. Clive Evans, director of the Core Laboratory Facility at the Virginia Bioinformatics Institute (VBI), said, “The availability of the Roche GS-FLX™ Titanium sequencing technology at VBI allowed the turkey research consortium to quickly and efficiently establish an early draft of the turkey genome.” This draft was extended in 2009 with data from the Illumina sequencing platform at the USDA-Agricultural Research Service and assembled by scientists at the University of Maryland to produce the current genome assembly. The use of these next-generation sequencing technologies provided the turkey genome sequence assembly at a fraction of the cost of producing the red junglefowl genome assembly (the same species as the domesticated chicken) in 2004. The international consortium spent the last year annotating and analyzing the draft genome sequence, which culminated in “fleshing out the intricacies of the turkey’s genetic blueprint as described in detail in the PLoS Biology paper,” Evans said. The research team hopes the integrated approach used to obtain the turkey genome will provide a model for creating gene- and chromosome-level assemblies for other species with agricultural, ecological, or evolutionary importance.

eBioNews
September 28, 2010

Original web page at eBioNews

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Salmonella contaminated pork may pose health risk for humans

German researchers have isolated a strain of Salmonella in pork that is closely related to the bacteria commonly found in chickens and linked to human food-borne illness. They report their findings in the July 2010 issue of the journal Applied and Environmental Microbiology. First emerging overseas in the mid-1990’s in pigs, initial studies showed the genetic make-up of Salmonella enterica subsp. enterica serovar Typhimurium (or S. enterica serovar 4,[5],12:i:-) to be very similar to S. enterica serovar Typhimurium, the strain commonly found in chickens. It is a known cause of gastroenteritis and has become increasingly associated with worldwide outbreaks over the last few years.

“Interestingly, the number of S. enterica serovar 4, [5],12:i:- strains isolated from humans and sent on voluntary basis to the National Reference Centre for Salmonella and other Enterics increased from 0.1% in 1999 to 14.0% in 2008,” say the researchers.In the study researchers collected and analyzed strains of S. enterica serovar 4,[5],12:i:-from pigs, pork, and humans over a two-year period in an attempt to better understand its transmission capabilities. Additionally, the strains’ genetic relatedness, pathogenicity and antimicrobial resistance were compared to that of S. enterica serovar Typhimurium. Two major clonal lineages were observed among the two strains and 65% of isolates from both lineages were resistant to ampicillin, streptomycin, tetracycline and sulfamethoxazole. “Overall the study indicates that in Germany S. enterica serovar 4, [5],12:i:- strains isolated from pig, pork, and human are highly related, showing their transmission along the food chain,” say the researchers. “Since the pathogenicity gene repertoire is highly similar to that of S. enterica serovar Typhimurium, it is essential that interventions are introduced at the farm level in order to limit human infection.”

Science Daily
August 3, 2010

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Keeping feces on the farm

To your health! Dairy cows graze next to a spray irrigator on a New Zealand farm. Think dairy farm, and your mind may wander to images of cows grazing dewy green pastures, as glistening silos and red-walled farmhouses slumber in the distance. But something sinister is lurking in the grass: cow feces crawling with disease-causing Escherichia coli bacteria. A new study, however, reveals that these bacteria are much less likely to enter groundwater and cause illness if farmers spray their fields with water rather than flooding them, as is traditional. In a previous study, chemist and environmental scientist Murray Close of the Institute of Environmental Science and Research in Christchurch, New Zealand, and colleagues investigated a high incidence of digestive illnesses among residents of a rural community in the southeastern region of the country. It turned out that nearby drinking wells were contaminated. When the researchers examined water from wells located near dairy pastures that used flood irrigation, they found E. coli from cow feces in about three-fourths of the samples.

In the new study, Close and colleagues looked at groundwater under New Zealand pastures watered with spray irrigation. During the 6-year study, they sampled groundwater from 10 plots of land every month for a total of roughly 700 samples. They found that only about 3% of the samples contained E. coli, compared with 77% in the previous experiment. Close attributes the large difference to the fact that bacteria escape to the groundwater more easily if the soil is wetter.

These results, reported in the May-June issue of the Journal of Environmental Quality, aren’t just important for human health, say experts. They should also help countries conserve more water, as some spray-irrigation systems are up to twice as efficient as flood irrigation. “About 70% of the freshwater use on the planet is related to agriculture, so there is going to be a need to make more investments in spray irrigation and use less water,” says economist Neilson Conklin, president of the Farm Foundation, a think tank in Oakbrook, Illinois. Plant biologist Molly Jahn, dean of the College of Agriculture and Life Sciences at the University of Wisconsin, Madison, says the new health incentive tips the balance in favor of spray irrigation despite the hefty price tag. (On a field housing 70 hungry cows, the cost of equipment alone can exceed $35,000.) Jahn says the next challenge will be to balance the costs and benefits. “What we’re trying to do in sustainable agriculture is make sure we get that calculus right.”

ScienceNow
July 6, 2010

Original web page at ScienceNow

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Faster Salmonella detection now possible with new technique

Using technology available through a local company, an Iowa State University researcher is working on a faster method to detect and genetically identify salmonella from contaminated foods. Byron Brehm-Stecher, an assistant professor of food science and human nutrition, wants to replace the current system of salmonella detection with a new approach that can provide DNA sequencing-like results in hours rather than days. Brehm-Stecher’s collaborator, Advanced Analytical Technologies, Inc., from Ames, is providing advanced biomedical instruments and reagents for the research. The recent results of the research, funded by the Grow Iowa Values Fund, will be presented at the August meeting of the International Association for Food Protection in Anaheim, Calif. Currently, definitive genetic identification of food-borne pathogens is done using traditional DNA sequencing methods first developed in the 1980s. “If you want (DNA) sequence information now, you first need to run a polymerase chain reaction (PCR) on total DNA extracted from a sample of contaminated food,” said Brehm-Stecher. “This amplifies DNA from the pathogen you’re looking for and will let you know if salmonella is present or not.

“However, further details about the pathogen are lacking, like what strain is present. To dig deeper, you need to run a cycle sequencing reaction — similar to a long PCR reaction — and send the output from this to a DNA sequencing core facility. Results are available about two days later,” said Brehm-Stecher. “This is not fast enough to keep up with the pace of today’s food production and distribution networks. We are able to get foods from the farm to the table — really any table around the globe — in a remarkably short period of time,” he added. Faster detection of specific strains can mean recognizing an outbreak sooner and stopping tainted food from being delivered and consumed. The new method might be helpful for investigative agencies, Brehm-Stecher said. “Especially for the type of investigation where things are still in motion. The food has been shipped and you may not know where it is. It may be in a truck, on a shelf or in some consumer’s pantry, so time really is of the essence,” he said.

“Next-generation sequencing tools are available, but these are still too complex and expensive for routine use in the food industry,” Brehm-Stecher explained. “New approaches that are able to bridge the gap between the limitations of traditional PCR and next-generation sequencing could enhance food safety efforts by providing both rapid presence/absence testing and detailed genetic characterization of isolates.” You don’t have to go further than the local newspaper to see the depth of the problem. Recent national outbreaks of salmonella in foods include peanut butter (2007 and 2009), alfalfa sprouts (2009), black pepper and hydrolyzed vegetable protein (HVP) (2010). Adding to the problem is the fact that peanut butter, black pepper and HVP are all base ingredients used in many other food products. Salmonella in these ingredients has led to thousands of product recalls, hundreds of illnesses and several deaths, Brehm-Stecher said. The method being developed at Iowa State University starts with a rapid PCR reaction that amplifies a salmonella-specific gene, generating millions of fluorescently labeled copies of this DNA in about 20 minutes.

Next, instead of cycle sequencing, the PCR product is purified for five minutes, SNAP71 (a reagent developed by Advanced Analytical) is added, and the DNA is heated for 10 minutes at 100ºC. This reaction chemically cuts the labeled salmonella DNA at all adenine and guanine sites (A’s and G’s) in the DNA chain. The result is a complex soup of fluorescently labeled DNA fragments of all sizes. These fragments are then separated in a high-voltage electric field by sieving them through a polymer matrix (a gel) contained in glass capillaries that are 50 microns — not much thicker than a human hair. This process separates the DNA fragments according to their size, from smallest to largest, and each piece is detected as it passes in front of an intense light source. For a PCR product that’s 300 bases long, this separation and detection process takes approximately 90 minutes. Because the SNAP71 reagent cleaves the salmonella DNA only at adenine and guanine, and not at thymine and cytosine sites (T’s and C’s), the method is not a direct replacement for DNA sequencing. Instead, the process rapidly generates a reproducible pattern of DNA fragments, Brehm-Stecher said. Salmonella strains having slightly different DNA sequences within a given gene will yield different patterns of fragments, allowing discrimination of different strains of salmonella. From “food to finish,” the whole process can be accomplished in about two and a half hours. “We’re very excited about this approach and about the rapid progress we’ve made since the project began,” said Brehm-Stecher. “The funding for this project has enabled us to work very closely with Advanced Analytical and accelerate application of their instruments to solving important food safety problems.”

Science Daily
June 8, 2010

Original web page at Science Daily

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Protecting pigs, cultivating consumers

The professor of swine health and production in the University of Minnesota College of Veterinary Medicine said that while producers have been busy putting food on plates, they have become distanced from the public. “Now we have few people farming, few farms raising hogs,” Dr. Davies said. “Our public is estranged from the livestock industry. They don’t know how farms operate.” He said critics attack animal agriculture from sociologic, ethical, health-related, and environmental platforms. “The problem is: There’s something there for nearly everyone,” he said. Dr. Davies was among presenters at the 41st annual meeting of the American Association of Swine Veterinarians who talked about the impact of persistent criticism of animal agriculture and what veterinarians can do to counter ignorance and misinformation. Other topics included porcine reproductive and respiratory syndrome, the novel H1N1 influenza virus, swine welfare, euthanasia, and bacterial disease. About 930 veterinarians, veterinary students, guest speakers, and technical-table representatives attended the meeting March 6-9 in Omaha, Neb.

Dr. Paul D. Ruen, who became the AASV president March 9, said in the opening session that the meeting was intended to improve veterinarians’ take-home knowledge and problem-solving skills. He said swine veterinarians are proud to help farmers, improve food safety, and do what is right for pigs and people. Dr. Davies said, “Pork … in the USA now is demonstrably safer than anytime in the past.” Taenia solium, Trichinella spiralis, and Toxoplasma gondii have been nearly eliminated in U.S. swine, which is a substantial public health accomplishment that is not given enough attention. Veterinarians need to show that their clients’ operations and their own practices are consistent with contemporary values and to take the debate over animal production to a nuanced level, Dr. Davies said. He thinks veterinarians also need to understand that farms performing poorly will be the ones shown to the public and that swine veterinarians can be easily discredited. “We’re only as good as our worst performance,” he said.

Dr. Paul R. DuBois of Cameron, Okla., said that if veterinarians avoid changing practices until change is forced on them, they will lose credibility and the opportunity to define their future. People enjoy pork products, but they have concerns and questions about animal care and handling. Food production rules are being shaped on the basis of emotion, he said, citing as examples referendums and laws regarding confinement animal housing. Veterinarians need to base their arguments on science but must also provide a message with emotional impact, Dr. DuBois said. He said they need to be ready to phase out practices for which they cannot explain the benefits in emotional terms. Dr. Rodney “Butch” Baker, 2009-2010 AASV president, said in an interview that critics caused the biggest challenges for the swine industry in 2009. “By bringing the animals indoors and creating biosecurity, we’ve truly eliminated about 15 diseases and parasites we had back to the 1980s,” Dr. Baker said. “There’s nothing wrong with raising them outdoors, but we look at survivability and welfare, and most of us believe that the confined animal operations provide a much better opportunity for the animals.” But concerns that the novel H1N1 virus may have originated in confined animal feeding facilities caused substantial losses for producers, even thought the virus had not been identified in North American pigs prior to the pandemic, Dr. Baker said.

Dr. James F. Lowe, a co-owner of Carthage Veterinary Service in Carthage, Ill., encouraged colleagues to make sure their tasks are improving pig health. “Doing is not implementing,” Dr. Lowe said. “Implementation is getting the pig to feel it. Doing is acting busy.” If nobody can measure the impact of an intervention, “nothing happened,” he said. Measurement—whether it involves the number of pigs, the weight of each pig, or the value of the meat—determines the success of an intervention. Dr. W.E. Morgan Morrow, a professor in the North Carolina State University College of Agriculture and Life Sciences, talked about the effect euthanasia of animals in production facilities can have on worker morale. Caretakers on farms and companion animal owners have some similar reactions to euthanasia, Dr. Morrow said, and production facility employees often try to give the animals in their care a chance to survive. Thus, to optimize worker morale and reduce worker stress, production facilities should work to identify those workers who least strongly object to performing euthanasia on sick animals and train those workers for this task. Dr. Morrow talked about research involving workers at 47 North Carolina farms and the attitudes those workers expressed toward euthanasia. About 46 percent of workers polled wished they did not have to euthanize animals, but 36 percent said such work was not stressful. In addition, 86 percent thought it was humane to euthanize animals rather than let them die, and 80 percent indicated they would use technology that took longer to euthanize pigs if it were less painful.

Dr. Jarod Hanson said dysentery is still present in U.S. swine, often as a co-infection. He said diarrhea resulting from co-infection with the organisms that cause dysentery and salmonellosis is often attributed entirely to the latter, and laboratories are not searching for evidence of swine dysentery unless asked. Dr. Hanson said depopulating a barn to eliminate dysentery requires not only killing the animals but also leaving the building empty for four to six weeks, a huge expense to producers. He also warned that workers and shared equipment can spread the causative bacterium, Brachyspira hyodysenteriae, to newly cleaned barns. Dr. J. Egan Brockhoff said a client’s 220-sow farrow-to-finish farm in western Alberta, Canada, had above-average production and minimal disease prior to becoming the first herd worldwide confirmed to be infected with the 2009 novel H1N1 influenza virus. He said he had visited the farm two or three times annually, and it had looked “awesome” during a visit on April 1, 2009. But on April 14, a sick carpenter who was later shown to have been infected with H1N1 entered the client’s swine barn to work on the ventilation system, two days after returning from a trip to Mexico, Dr. Brockhoff said. The seven production areas in the barn had shared airspace that provided “a great place for influenza to have a party.”

The producer noticed increased coughing by the pigs starting April 20, and Dr. Brockhoff notified provincial animal health authorities April 28 following an examination that revealed illnesses. Two of the three Canadian Food Inspection Agency inspectors who arrived that night became ill, despite wearing protective equipment. Pigs became ill throughout sections of the barn where the ventilation work had occurred, but clinical signs of the flu were nothing new, Dr. Brockhoff said. Many of the animals were pyrexic, moderately depressed, anorexic, and mildly dehydrated, while two had rectal prolapses. About 475 finisher pigs were culled May 8 to prevent overcrowding and sent to a renderer. Although the pigs had displayed no clinical signs of illness by June 4, the owner insisted on depopulating the 3,000 remaining pigs because of his inability to sell to markets. Dr. Amy L. Vincent, a veterinary medical officer in the Agricultural Research Service of the Department of Agriculture, said analysis of eight gene segments from each of 12 swine influenza virus strains found in U.S. herds in 2008 and from strains of the 2009 novel H1N1 influenza virus indicated that the pandemic virus strains differed from the 2008 strains in all eight segments, meaning that the virus was new to U.S. herds. She said ARS study of the pandemic influenza virus indicated that the virus can easily be transmitted to naïve pigs, causes signs similar to those of other influenza virus infections, and has potential to cause severe pneumonia and disease in some pigs.

Pork producers lost hundreds of millions of dollars because of influenza concerns, market difficulties, and the global recession, but they are starting to see profits again, Dr. Baker said. He remains concerned about the connection between corn and energy production and the impact of energy prices on feed prices. “We’re just one bad global crop year from an absolute food crisis in the world, and we saw that with rising fuel costs and then food costs,” Dr. Baker said. “When you connect a foodstuff like corn to energy, we see that, once oil rises above about $80 a barrel, then the cost and the market value of corn follow.” But on the upside, swine veterinarians have tools to fight novel H1N1 influenza infections, and the economy is improving, Dr. Baker said. He thinks 2010 will be a good year for producers, barring any large-scale negative events.

JAVMA
May 25, 2010

Original web page at JAVMA

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Bluefin and bigeye tuna sushi contains mercury levels that sometimes surpass FDA limits

Sushi lovers should think twice before ordering another helping of maguro rolls. Mercury levels in restaurant tuna sushi are higher than those of supermarket tuna sushi, a new study reveals. Mercury tends to concentrate in species at the top of the food chain; the larger the species, the greater the threat. That’s a worrisome fact for sushi lovers, as the prized bluefin tuna can weigh more than 500 kilograms. Because of tuna’s levels of mercury, which can cause severe neurological problems in humans, the U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) warn that pregnant women and young children should limit the amount they consume. But that’s just general advice; mercury levels may not be the same for all tuna species. To complicate matters, sushi restaurants often do not tell diners exactly which species of tuna they’re getting.

Michael Gochfeld, an environmental toxicologist at Rutgers University in New Brunswick, New Jersey, wanted to find out which types of tuna pose the greatest risk. Using DNA bar coding, a technique that categorizes organisms based on specific genetic markers, Gochfeld and his team identified five species served in 100 sushi samples from 54 restaurants and 15 supermarkets. They also measured mercury levels in each sample, as the researchers report today in Biology Letters. The team found that restaurants sold tuna sushi with higher levels of mercury than supermarkets. Bigeye tuna or lean bluefin tuna, which are more common in restaurants, had concentrations that approached or overshot by about 4% the FDA limit— of 1.0 parts per million. The study gives another reason to avoid eating bluefin, which is a threatened species, Gochfeld says. Regulatory agencies should specifically mention bluefin and bigeye tuna in mercury advisories, he says. Yellowfin tuna, a cheaper and more plentiful species found in supermarket sushi, contained less mercury. Yet samples from all species exceeded the daily EPA limits (more conservative than those of FDA, which also incorporates the nutritional benefits of fish) and the concentrations permitted by Japan’s health ministry. What’s more, measures of mercury concentration in bigeye and yellowfin tuna samples surpassed previous FDA estimates.

“It’s absolutely a completely novel use of bar coding in the area of consumer protection,” says David Schindel, who leads the Consortium for the Barcode of Life in Washington, D.C. He noted one previous study that used DNA bar coding to identify poisonous puffer fish mislabeled as monkfish, but this is the first to use the technology to assess the relative risk of fish consumption. Gochfeld hopes the findings will start to put pressure on supermarkets and restaurants to accurately label tuna species. In the meantime, consumers should beware what they eat. “If you’re going to eat sushi frequently, you should certainly stay away from tuna sushi,” Gochfeld says. “It should be only an occasional treat.”

ScienceNow
May 11, 2010

Original web page at ScienceNow