It’s not just a grunt: Pigs really do have something to say

The grunts made by pigs vary depending on the pig’s personality and can convey important information about the welfare of this highly social species, new research has found.

Scientists specialising in animal behaviour and welfare devised an experiment to investigate the relationship between personality and the rate of grunting in pigs. They also examined the effect different quality living conditions had on these vocalisations.

Findings from the study, carried out by researchers from the University of Lincoln, UK, and Queens University Belfast, are published in the Royal Society journal Open Science.

The study involved 72 male and female juvenile pigs. Half were housed in spacious ‘enriched’ pens with straw bedding, while the other half were kept in more compact ‘barren’ pens with partially slatted concrete floors, which adhered to UK welfare requirements.

To get a measure of the pigs’ personalities, the researchers conducted two tests: a social isolation test and a novel object test. Each pig spent three minutes in social isolation, and five minutes in a pen with a large white bucket or an orange traffic cone they had not previously encountered. Their behaviour, including vocalisations, were observed. These tests were repeated two weeks later, allowing the researchers to determine if the pigs’ responses were repeatable — the defining characteristic of personality (also known as ‘coping style’ in animals).

They also recorded the frequency of grunts they made by counting the number of grunts produced per minute of the test, and investigated the effect different quality environments had on the sounds made.

The study indicated that pigs with more proactive personality types produced grunts at a higher rate than the more reactive animals. The study also found that male pigs (but not females) kept in the lower-quality conditions made fewer grunts compared with those housed in the enriched environment, suggesting greater susceptibility among male pigs to environmental factors.

The results add to evidence that acoustic signalling indicates personality in pigs. This may have had far reaching consequences in shaping the evolution of social behaviours, the researchers believe. The findings also suggest personality needs to be kept in mind when using vocalisation as a measure of the animals’ welfare status.

Principal investigator, Dr Lisa Collins, a specialist in animal health, behaviour and welfare epidemiology in the School of Life Sciences at the University of Lincoln, said: “The domestic pig is a highly social and vocal species which uses acoustic signals in a variety of ways; maintaining contact with other group members while foraging, parent-offspring communication, or to signal if they are distressed.

“The sounds they make convey a wide range of information such as the emotional, motivational and physiological state of the animal. For example, squeals are produced when pigs feel fear, and may be either alerting others to their situation or offering assurance. Grunts occur in all contexts, but are typical of foraging to let other members of the group know where they are.”

Mary Friel, lead author of the study and PhD student at Queen’s University Belfast, added: “The aim of this research was to investigate what factors affect vocalisations in pigs so that we can better understand what information they convey. Understanding how the vocalisations of pigs’ relate to their personality will also help animal behaviourists and welfare experts have a clearer picture of the impact those personalities have on communication, and thus its role in the evolution of social behaviour and group dynamics in social species.” Science Daily  Original web page at Science Daily


* Researchers first to grow living bone that replicates original anatomical structure

A new technique developed by Gordana Vunjak-Novakovic, the Mikati Foundation Professor of Biomedical Engineering at Columbia Engineering and professor of medical sciences (in Medicine) at Columbia University, repairs large bone defects in the head and face by using lab-grown living bone, tailored to the patient and the defect being treated. This is the first time researchers have grown living bone that precisely replicates the original anatomical structure, using autologous stem cells derived from a small sample of the recipient’s fat. The study is published today in Science Translational Medicine.

“We’ve been able to show, in a clinical-size porcine model of jaw repair, that this bone, grown in vitro and then implanted, can seamlessly regenerate a large defect while providing mechanical function,” says Vunjak-Novakovic, who is also the director of Columbia’s Laboratory for Stem Cells and Tissue Engineering, co-director of the Craniofacial Regeneration Center, and director of the Bioreactor Core of the NIH Tissue Engineering Center. “The need is huge, especially for congenital defects, trauma, and bone repair after cancer surgery. The quality of the regenerated tissue, including vascularization with blood perfusion, exceeds what has been achieved using other approaches. So this is a very exciting step forward in improving regenerative medicine options for patients with craniofacial defects, and we hope to start clinical trials within a few years.”

Vunjak-Novakovic’s team, which included researchers from Columbia Engineering’s Department of Biomedical Engineering, Columbia’s College of Dental Medicine, Louisiana State University, and Tulane University School of Medicine, fabricated a scaffold and bioreactor chamber based on images of the weight-bearing jaw defect, to provide a perfect anatomical fit. The scaffold they built enabled bone formation without the use of growth factors, and also provided mechanical function, both of which are unique advantages for clinical application. They then isolated the recipient’s own stem cells from a small fat aspirate and, in just three weeks, formed the bone within a scaffold made from bone matrix, in a custom-designed perfused bioreactor. To mimic the logistics of envisioned clinical applications, where the patient and the bone manufacturing are at remote locations far from each other, the researchers shipped the bioreactor with the living bone across the country to be implanted.

An unexpected outcome was that the lab-grown bone, when implanted, was gradually replaced by new bone formed by the body, a result not seen with the implantation of a scaffold alone, without cells. “Our lab-grown living bone serves as an ‘instructive’ template for active bone remodeling rather than as a definitive implant,” says Vunjak-Novakovic. “This feature is what makes our implant an integral part of the patient’s own bone, allowing it to actively adapt to changes in the body throughout its life.”

Vunjak-Novakovic and her team are now including a cartilage layer in the bioengineered living bone tissue to study bone regeneration in complex defects of the head and face. They are also advancing their technology through advanced preclinical trials, and in planning stages with the FDA for clinical trials, through her company epiBone.

“Having a chance to work on innovative research that may be part of our future is intriguing, energizing, and really inspiring,” says the study’s lead author Sarindr Bhumiratana PhD’12, who also is chief scientific officer at epiBone.

“Today, tissue engineering is truly changing the way we approach tissue repair, drug testing, disease modeling,” Vunjak-Novakovic adds. “In all these diverse areas, we now can put the cells to work for us and make tissues, by providing bioengineered environments that mimic their native milieu.”  Science Daily Original web page at Science Daily


Diet lacking in zinc is detrimental to human, animal health

The trace element zinc has an impact on the essential metabolic functions of most living organisms. New research carried out by the Chair of Animal Nutrition at the Technical University of Munich (TUM) has found that even minimal zinc deficiency impairs digestion, albeit without any typical symptoms such as skin problems or fatigue. Hence, short-term zinc deficiency in the diet should be avoided.

The test series established that even slight zinc deficiency in an animal’s diet impedes pancreatic digestive activity and results in significant digestive impairment, even at an early stage. The study undertaken by Daniel Brugger of the Chair of Animal Nutrition at TUM was recently published in the British Journal of Nutrition.

Scientist Brugger charted a new path since all previous studies had compared the functions of animals with clinical zinc deficiency to those of animals that had adequate amounts of this trace element in their bodies. “It is important to note that, in nature, clinical zinc deficiency does not really occur, neither in animals nor in humans,” explains lead author Brugger. Hence, Brugger carried out his study on animals with short-term or subclinical zinc deficiency. As the trace element only exists in small amounts in an organism, it has to be consumed by way of nutrition. In piglets, for instance, a clinical or manifest zinc deficiency can — under feeding conditions applied in practice — only be achieved after about ten days, explains the TUM scientist. This is why he ended his test series early, after just eight days.

The unnoticed start of zinc depletion occurs without any visible symptoms, but minute changes can be identified in the liver and in the blood. For the purpose of this study, piglets which had just been weaned were fed a diet containing different amounts of zinc to develop early-stage zinc deficiency. This was the only way for the scientists to trace and analyze what effects dwindling zinc deposits would have on the animals’ metabolisms. On one hand, it was observed that the body tried to absorb zinc more efficiently, while on the other, it reduced pancreatic zinc excretion. Since clinical zinc deficiency reduces the test animals’ appetite, “various hypotheses were derived, for example, that zinc deficiency had a direct impact on the vagus nerve. The real reason, however, may be much simpler: the accumulation of undigested food inside the gastrointestinal tract due to zinc deficiency results in feeling less hungry,” says Brugger.

The pancreas is the control center for food digestion and energy homeostasis in the body. It pumps zinc into the gastrointestinal tract in order to maintain a consistent zinc level. Conversely, if an organism is depleted of zinc, it reduces its pancreatic zinc excretion to a minimum. The starting point for Daniel Brugger’s study was the hypothesis that this mechanism may be related to digestion.

Feed digestion is of enormous importance for growing livestock and especially the first few weeks after young animals are weaned from their mothers are of crucial importance. This is a factor that must not be underestimated by farmers.

“We proved that there is a direct correlation between the amount of digestive enzymes inside the pancreas and zinc levels in the organism as a whole,” explains Brugger. “Even short intervals of zinc deficiency in the diet should therefore be avoided. Given the similarities between a pig’s organism and the human organism, we may draw the following conclusion when applying our results to the human body: an egg or two more once in a while can do no harm.” Brugger advises vegans, vegetarians and older people to monitor their zinc intake. Among other things, a subclinical zinc deficiency in humans has been attributed to increased levels of inflammation markers and reduced immunocompetence.  Science Daily Original web page at Science Daily


Supervised autonomous in vivo robotic surgery on soft tissues is feasible

The study, published today in Science Translational Medicine, reports the results of soft tissue surgeries conducted on both inanimate porcine tissue and living pigs using proprietary robotic surgical technology, Smart Tissue Autonomous Robot (STAR), developed at Children’s National. This technology removes the surgeon’s hands from the procedure, instead utilizing the surgeon as supervisor, with soft tissue suturing autonomously planned and performed by the STAR robotic system.

Soft tissues are the tissues that connect, support or surround other structures and organs of the body such as tendons, ligaments, fascia, skin, fibrous tissues, fat, synovial membranes, muscles, nerves and blood vessels. Currently more than 44.5 million soft tissue surgeries are performed in the U.S. each year.

“Our results demonstrate the potential for autonomous robots to improve the efficacy, consistency, functional outcome and accessibility of surgical techniques,” said Dr. Peter C. Kim, Vice President and Associate Surgeon-in-Chief, Sheikh Zayed Institute for Pediatric Surgical Innovation. “The intent of this demonstration is not to replace surgeons, but to expand human capacity and capability through enhanced vision, dexterity and complementary machine intelligence for improved surgical outcomes.”

While robot-assisted surgery (RAS) has increased in adoption in healthcare settings, the execution of soft tissue surgery has remained entirely manual, largely because the unpredictable, elastic and plastic changes in soft tissues that occur during surgery, requiring the surgeon to make constant adjustments.

To overcome this challenge, STAR uses a tracking system that integrates near infrared florescent (NIRF) markers and 3D plenoptic vision, which captures light field information to provide images of a scene in three dimensions. This system enables accurate, uninhibited tracking of tissue motion and change throughout the surgical procedure. This tracking is combined with another STAR innovation, an intelligent algorithm that guides the surgical plan and autonomously makes adjustments to the plan in real time as tissue moves and other changes occur. The STAR system also employs force sensing, submillimeter positioning and actuated surgical tools. It has a bed-side lightweight robot arm extended with an articulated laparoscopic suturing tool for a combined eight degrees-of-freedom robot.

“Until now, autonomous robot surgery has been limited to applications with rigid anatomy, such as bone cutting, because they are more predictable,” said Axel Krieger, PhD, and technical lead for Smart Tools at Sheikh Zayed Institute for Pediatric Surgical Innovation at Children’s National. “By using novel tissue tracking and applied force measurement, coupled with suture automation software, our robotic system can detect arbitrary tissue motions in real time and automatically adjust.”

To compare the effectiveness of STAR to other available surgical procedures, the study included two different surgeries performed on inanimate porcine tissue (ex vivo), linear suturing and an end-to-end intestinal anastomosis, which involves connecting the tubular loops of the intestine. The results of each surgery were compared with the same surgical procedure conducted manually by an experienced surgeon, by laparoscopy, and by RAS with the daVinci Surgical System.

Intestinal anastomosis was the surgical procedure conducted on the living subjects (in vivo) in the study. The Children’s National research team conducted four anastomosis surgeries on living pigs using STAR technology and all subjects survived with no complications. The study compared these results to the same procedure conducted manually by an experienced surgeon using standard surgical tools.

“We chose the complex task of anastomosis as proof of concept because this soft tissue surgery is performed over one million times in the U.S. annually,” said Dr. Kim.

All surgeries were compared based on the metrics of anastomosis including the consistency of suturing based on average suture spacing, the pressure at which the anastomosis leaked, the number of mistakes that required removing the needle from the tissue, completion time and lumen reduction, which measures any constriction in the size of the tubular opening.

The comparison showed that supervised autonomous robotic procedures using STAR proved superior to surgery performed by experienced surgeons and RAS techniques, whether on static porcine tissues or on living specimens, in areas such as consistent suture spacing, which helps to promote healing, and in withstanding higher leak pressures, as leakage can be a significant complication from anastomosis surgery. Mistakes requiring needle removal were minimal and lumen reduction for the STAR surgeries was within the acceptable range.

In the comparison using living subjects, the manual control surgery took less time, eight minutes versus 35 minutes for the fastest STAR procedure, however researchers noted that the duration of the STAR surgery was comparable to the average for clinical laparoscopic anastomosis, which ranges from 30 minutes to 90 minutes, depending on complexity of the procedure.

Dr. Kim said that since supervised, autonomous robotic surgery for soft tissue procedures has been proven effective, a next step in the development cycle would be further miniaturization of tools and improved sensors to allow for wider use of the STAR system.

He added that, with the right partner, some or all of the technology can be brought into the clinical space and bedside within the next two years.  Science Daily Original web page at Science Daily


* Using precision-genetics in pigs to beat cancer

Pigs could be a valuable alternative to rodent models of cancer. The numbers are staggering: more than 40 % is the lifetime risk of developing cancer in the U.S., with only 66 % survival-rates 5 years after diagnosis, for all types of cancer. Trends suggest that in 2015, over 1.6 million new cases were diagnosed in the U.S., with over 580,000 deaths in consequence.

These numbers emphasize the need to better understand and treat the various forms of the disease, but mouse models usually used in cancer research have given us limited answers. However, Senior Scientist Adrienne Watson and colleagues at Recombinetics and the University of Minnesota, say that pigs may turn out to be the best alternative models.

“Many organ systems vary so greatly between rodents and humans that certain types of cancer cannot be accurately modelled,” says Watson, despite the major role mouse models have played in our understanding of the disease. The authors conclude that the five deadliest cancers in the U.S. cannot be modeled in rodents, or have ineffective models for identification of treatments that translate to the clinic.

Cancer is a genetic disease where cells acquire or inherit genetic mutations, which result in malfunctioning proteins that cause uncontrolled growth of cells in the blood or solid organs. “The anatomical, physiological, and genetic similarities between swine and humans are striking, suggesting that disease modeling in this large animal may better represent the development and progression of cancer seen in people.”

The authors explain, in their article that was published recently in Frontiers in Genetics, that new technology in precision-genetics, when applied to pigs, will lead the way, and could become especially advantageous when conducting targeted gene-editing using custom endonucleases, such as TALENs and CRISPRs, and transposon systems. “We can now engineer exact human disease alleles into the pig genome, to make novel models not available in rodents. They are incredibly valuable for their broader preclinical applications.”

Using genetically modified pigs would allow overcoming one of the main drawbacks of rodent models, which is their inability so far to identify safe and effective drugs to treat cancer. For example, the size and ease in handling pigs allows for drugs to be administered in the same way as in patients, and for follow up blood-work over time.

The authors caution that, as for any novel animal model to be useful in cancer research, it must be adopted and fully tested in many laboratories and under many circumstances. But the higher costs involved in handling these animals in the laboratory setting may be well worth the gains in our understanding of this deadly disease. Science Daily  Original web page at Science Daily


* Much longer survival for heart transplants across species

A new immune-suppressing therapy has led to the longest survival yet for a cross-species heart transplant, according to new research conducted in part by researchers at the University of Maryland School of Medicine (UM SOM).

The study involved transplanting pig hearts into baboons. The results could lead to increased use of xenotransplantation, the transplantation of organs from one species to another. Researchers hope this approach could eventually be used in humans, helping the severe organ shortage among patients awaiting transplantation.

The study, which was conducted at the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, was published yesterday in Nature Communications.

A key problem with using xenotransplantion with humans is that the immune system reacts very strongly, which can cause organ rejection. Scientists have tried modifying the organ donor’s genes and developing novel immune-suppressing drugs for the organ recipients.

In the current study, scientists developed a novel immune-suppressing drug regimen that includes a key antibody, called anti-CD40 antibody, which may help the organ resist the immune system response. The researchers used pigs that had been genetically modified to have high immune system tolerance and then transplanted hearts from these animals into a group of five baboons. The pig heart did not replace the baboon heart, but was an additional organ. Both the new and original hearts continued to pump blood.

With the new immune-suppressing drugs, the pig hearts survived for up to 945 days in the baboons — much longer than previous pig-to-primate heart transplants. The immune-suppressing drugs played a key role in this.

“This has the potential to really move the field forward,” said Richard Pierson, a professor of surgery at UM SOM, one of the co-authors. He has studied xenotransplantation for three decades. “This new approach clearly made a difference. We obviously have a lot more work to do, but I’m confident that eventually this will be useful to human patients.”

The study’s lead author was Muhammad Mohiuddin, MD, chief of the transplantation section in the Cardiothoracic Surgery Research Program at the NHLBI.  Science Daily  Original web page at Science Daily


Investigators trace emergence and spread of virulent salmonella strain

Since it first emerged more than half a century ago, a particular strain of multidrug-resistant Salmonella has spread all over the world. Now researchers have figured out why this strain, Salmonella Typhimuriam DT104, has been so successful. This new knowledge could prove valuable in combating other successful pathogens, according to the authors. The study is published ahead of print March 4th in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

In order to construct the history of this strain, the investigators performed whole-genome sequencing of samples of DT104 that had been collected from patients over more than 40 years, from 1969 to 2012, in 21 countries, on six continents. Very tiny changes in the genome that took place over time enabled them to construct the strain’s family tree (which scientists call a phylogenetic tree). The sequences have also made it easy to estimate roughly when the pathogen acquired the resistance genes.

DT104’s success was due in no small part to its resistance to at least five antibiotics, including ampicillin, chloramphenicol, streptomycin, sulphonamide, and tetracycline, said corresponding author, Pimlapas Leekitcharoenphon, PhD.

Further abetting its spread, unlike other strains of DT Salmonella, DT104 was able to infect numerous livestock species, including cattle, poultry, pigs, and sheep, said Leekitcharoenphon. “Having multiple hosts increases the chances of dissemination,” she explained. Leekitcharoenphon is a postdoctoral researcher at the Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, Lyngby.

Using a program that took into account the rate of mutations in DT104, the investigators estimated that it first emerged in 1948 as an antibiotic susceptible pathogen. It is not clear exactly when DT104 first acquired the multidrug resistance-containing transposon. Transposons are mobile genetic elements that can carry antibiotic resistance genes, and that can jump from one genome to another. In the case of DT104, transposons have been identified as the sources of the resistance genes. The study suggests that the first acquisition of antibiotic resistance may have happened in 1972. However, multidrug-resistant DT104 was first reported in 1984 in the United Kingdom.

The new results also illuminated, for the first time, the results of a program in Denmark to eradicate all pigs infected with DT104, which had begun in 1996, but was stopped in 2000 due to financial pressures. It turns out that program was quite successful.

“If we know and understand the past, we might be able to solve the current resistance problems and prevent future ones,” said Leekitcharoenphon.  Science Daily  Original web page at Science Daily


New virus transmission route discovered in pigs

Japanese Encephalitis (JE) virus causes serious inflammation of the brain in people and fertility problems in pigs. Mosquitoes were previously the only known transmission route. However, the virus can also be spread from pig to pig by direct contact, and this could enable it to circulate in pigs during the mosquito-free winter season.

The JE virus is the main cause of serious encephalitis in people in Asia. The virus is found in large parts of Southeast Asia and is now also widespread in India. It circulates between birds and mosquitoes and between pigs and mosquitoes, and is passed to humans through mosquito bites. In children in particular, infection can lead to acute encephalitis and permanent impairment or even death.

In pigs, the main effect of the virus alongside fever and encephalitis is fertility problems. The virus is closely related to the West Nile, Zika and dengue viruses. All are transmitted by mosquitoes and are flaviviruses, which cause serious illness in humans and animals.

Previously, the only known transmission route for JE viruses was mosquitoes. A team of researchers from the Institute of Virology and Immunology and the University Bern at the Vetsuisse Faculty led by Dr. Meret Ricklin and Prof Artur Summerfield have now shown that JE viruses can also be passed directly from pig to pig. The study has just been published in the journal “Nature Communications.”

Up to now, there had been no explanation for how the JE virus could survive over winter in regions such as the northern Japanese island of Hokkaido, and cause new outbreaks the following year. Outbreaks in some cases occurred on the same farms as in the previous year, despite the fact that no infected mosquitoes could be found in the area. In Taiwan, too, pigs were infected with JE viruses during the winter, but no infected mosquitoes found.

As the researchers have now been able to show, infected pigs discharge the virus in their saliva for several days, and the animals are also susceptible to infection through the mouth or nose with very low doses of the virus. In pigs — as in humans — the virus was found to spread through the brain and cause inflammation. The virus was, however, found to grow most in the tonsils, where it was detectable for several weeks or even months. The authors suggest that JE viruses could possibly circulate in pigs and survive for up to months. When the virus is secreted again, for example as a result of a different infection that weakens the immune system, a new infection cycle could then begin. However, the researchers say that further studies are needed to prove this link.

The study published shows that even for viruses that are spread by insect bites, direct transmission through animal to animal contact cannot be ruled out. “This means that the virus could circulate within the pig population without mosquitoes, and thus spread even to regions with a temperate climate,” says Artur Summerfield. This would theoretically also mean a higher risk to humans. A vaccine is, however, available for both people and animals. The virus has to date only occurred in Europe in travellers returning from Asia and in those cases did not lead to any further infections.

The Institute of Virology and Immunology (IVI) with sites at Mittelhäusern and Bern is the Swiss reference laboratory for the diagnosis, surveillance and control of highly infectious animal diseases. IVI is part of the Swiss Federal Food Safety and Veterinary Office (FSVO).

As part of cooperation with the Vetsuisse Faculty of the University of Bern, the IVI is responsible for teaching and research in the field of virology and immunology. Research activities include both basic and applied research, and provide an important basis for the control of animal diseases and zoonoses (infectious diseases that can be spread between humans and animals).   Science Daily  Original web page at Science Daily


Porcine epidemic diarrhea virus and discovery of a recombinant swine enteric coronavirus, Italy

Porcine epidemic diarrhea virus (PEDV) has been detected sporadically in Italy since the 1990s. We report the phylogenetic relationship of swine enteric coronaviruses collected in Italy during 2007–2014 and identify a drastic shift in PEDV strain variability and a new swine enteric coronavirus generated by recombination of transmissible gastroenteritis virus and PEDV.

Porcine epidemic diarrhea virus (PEDV) and Transmissible gastroenteritis virus (TGEV) (family Coronaviridae, genus Alphacoronavirus) are enveloped viruses that contain a single-stranded, positive-sense RNA genome of ≈28 kb. Infection with these viruses causes watery diarrhea, dehydration, and a high mortality rate among suckling pigs. Coronaviruses (CoVs) are prone to genetic evolution through accumulation of point mutations and homologous recombination among members of the same genus. Porcine respiratory coronavirus (PRCV), a mutant of TGEV, appeared in pigs in the 1980s. The spread of PRCV, which conserved most of the antigenic sites and causes cross-protection against TGEV, led to the gradual disappearance of TGEV. Newly emerging CoVs pose a potential threat to human and animal health because multiple human CoV infections have been derived from animal hosts. Emerging swine coronaviruses are of great concern to swine health because of the potential increase in viral pathogenesis.

In 1978, PEDV was first identified in Europe; subsequent reports occurred in many countries in Asia, including China, Japan, Korea, and Thailand. In 2010–2012, genetically different PEDV strains emerged, causing severe outbreaks in China. PEDV spread to the United States, Canada, and Mexico in 2013–2014, and genetically related strains were detected in South Korea and Taiwan. The PEDV outbreak caused large global economic losses to the swine industry. In Europe, a severe PEDV epidemic occurred in Italy during 2005–2006 (8), and in 2014–2015, PEDV was detected in Germany, France, and Belgium. These strains have a high nucleotide identity to PEDV strains that contain distinct insertions and deletions (INDELs) in the S gene (S-INDELs) from the United States). We report the detection and genetic characterization of swine enteric CoVs circulating in Italy during 2007–2014. We also report a recombinant TGEV and PEDV strain (identified as the species Swine enteric coronavirus [SeCoV]) circulating from June 2009 through 2012. Finally, we describe the phylogenetic relationship of the 2014 PEDV S-INDELs to the recent PEDV strains circulating in Europe.

During 2007–2014, most (92%) samples collected from the Po Valley in Italy were positive for PEDV by ELISA; only 72% were positive by pan-CoV PCR. However, because we were investigating the presence of PEDV or TGEV in samples with clinical signs of diarrhea, the high occurrence of PEDV may not reflect the actual prevalence of PEDV in Italy. The increased percentage of PEDV found in samples tested by ELISA, compared with the proportion found by PCR, may be explained by the number of ambiguous bases in the pan-CoV primers; the ambiguous bases severely reduce the efficiency of the reaction. The swine enteric CoV strains from Italy in our study, including the recombinant strain, were reported in pigs with mild clinical signs, indicating that PEDV and SeCoV have been circulating in Italy and likely throughout Europe for multiple years but were underestimated as a mild form of diarrhea.

To understand the evolution of PEDV in Italy, the partial RdRp, S, and M genes were sequenced from 18 samples and grouped in 3 different temporal clusters. Cluster I (2007–mid 2009) resembles the oldest PEDV strains; cluster II resembles a new TGEV and PEDV recombinant variant; and cluster III, identified from 2 pig farms in northern Italy in 2014, resembles the PEDV S-INDEL strains identified in Germany, France, Belgium, and the United States. The >99.3% nt identity of the S1 gene within cluster III and in previously identified strains could suggest the spread of the S-INDEL strain into Europe. However, directionality of spread cannot be determined because of a lack of global and temporal PEDV sequences.

Although our findings could indicate 3 introductions of PEDV in Italy, the results more likely suggest the high ability of natural recombination among CoVs and the continued emergence of novel CoVs with distinct pathogenic properties. Further investigation is needed to determine the ancestor of the SeCoV strain or to verify whether the recombinant virus was introduced in Italy. Recombinant SeCoV was probably generated in a country in which both PEDV and TGEV are endemic, but because the presence of these viruses in Europe is unclear and SeCoV has not been previously described, it is difficult to determine the parental strains and geographic spread of SeCoV. Future studies are required to describe the pathogenesis of SeCoV and its prevalence in other countries.  Emerging Infectious Diseases  Original web page at Emerging Infectious Diseases


Detection of influenza D virus among swine and cattle, Italy

Recent studies have identified a new genus of the Orthomyxoviridae family. The virus, distantly related to human influenza C virus, has been provisionally designated as influenza D virus. This novel virus was identified for the first time in pigs with influenza-like illness, but subsequent serologic and virologic surveys have suggested cattle as a possible reservoir. Moreover, the virus was shown to infect ferrets used in laboratories as surrogates for humans when investigating influenza infection. In a serologic study conducted on 316 human samples, low antibody titers and a low level of positive samples were detected, suggesting that humans are a possible host to be studied in depth. To investigate the circulation of influenza D viruses among pigs and cattle in Italy, we performed biomolecular and virological tests on clinical samples collected from respiratory outbreaks in Po Valley, the area in Italy with the highest density of swine and cattle farms.

Clinical specimens were screened from swine (n = 150) and cattle (n = 150) for influenza D virus by reverse transcription quantitative PCR. Three nasal swab samples were found positive: 1 from a sow and 2 from cattle, collected from 3 farms located at linear distances ranging from 47 to 80 km. All positive samples were confirmed by partial polymerase basic 1 gene sequencing and submitted to viral isolation in cell cultures as previously described. The virus was isolated on CACO-2 and HRT18 cell cultures only from the sow sample. Cell cultures were tested by using reverse transcription quantitative PCR. Viral RNA was isolated from clinical samples or cell culture by using One-For-All Vet Kit (QIAGEN, Milan, Italy). Full-genome amplification from influenza D virus–positive samples was achieved as previously described. A sequencing library of the purified amplicons was prepared by using NEXTERA-XT kit and sequenced by using a Miseq Reagent Kit v2 in a 250-cycle paired-end run (both from Illumina Inc., San Diego, CA, USA). Sequencing reads were assembled de novo or by using D/swine/Oklahoma/1334/2011 (GenBank accession nos. JQ922305–JQ922311) as a template by Seqman NGen DNASTAR version 11.2.1 (DNASTAR, Madison, WI, USA). Gene sequences from the 3 influenza D viruses isolated in Italy and all the available influenza D virus sequences retrieved from GenBank were aligned with ClustalW by using MEGA5. We analyzed the predicted amino acid sequences for each gene.  Emerging Infectious Diseases  Original web page at Emerging Infectious Diseases


* Gene-edited ‘micropigs’ to be sold as pets at Chinese institute

The pigs are endearing but scientists warn that they may be a distraction from more serious research. Cutting-edge gene-editing techniques have produced an unexpected byproduct — tiny pigs that a leading Chinese genomics institute will soon sell as pets.

BGI in Shenzhen, the genomics institute that is famous for a series of high-profile breakthroughs in genomic sequencing, originally created the micropigs as models for human disease, by applying a gene-editing technique to a small breed of pig known as Bama. On 23 September, at the Shenzhen International Biotech Leaders Summit in China, BGI revealed that it would start selling the pigs as pets. The animals weigh about 15 kilograms when mature, or about the same as a medium-sized dog.

At the summit, the institute quoted a price tag of 10,000 yuan (US$1,600) for the micropigs, but that was just to “help us better evaluate the market”, says Yong Li, technical director of BGI’s animal-science platform. In future, customers will be offered pigs with different coat colours and patterns, which BGI says it can also set through gene editing.

With gene editing taking biology by storm, the field’s pioneers say that the application to pets was no big surprise. Some also caution against it. “It’s questionable whether we should impact the life, health and well-being of other animal species on this planet light-heartedly,” says geneticist Jens Boch at the Martin Luther University of Halle-Wittenberg in Germany. Boch helped to develop the gene-editing technique used to create the pigs, which uses enzymes known as TALENs (transcription activator-like effector nucleases) to disable certain genes.

How to regulate the various applications of gene-editing is an open question that scientists are already discussing with agencies across the world. BGI agrees on the need to regulate gene editing in pets as well as in the medical research applications that make up the core of its micropig activities. Any profits from the sale of pets will be invested in this research. “We plan to take orders from customers now and see what the scale of the demand is,” says Li.

Compared to rats or mice, pigs are closer to humans physiologically and genetically, making them potentially more useful as a model organism for human disease. However, their larger size means that they cost more to keep and require bigger drug doses when they are used to test a pricey experimental medicine. Bama pigs, which weigh 35–50 kilograms (by contrast, many farm pigs weigh more than 100 kilograms), have previously been used in research.

To make the smaller, gene-edited micropigs, BGI made cloned pigs from cells taken from a Bama fetus. But before they started the cloning process, they used TALENs to disable one of two copies of the growth hormone receptor gene (GHR) in the fetal cells. Without the receptor, cells do not receive the ‘grow’ signal during development, resulting in stunted pigs.

BGI then created further micropigs by breeding stunted male clones with normal females. Only half of the resulting, naturally conceived offspring were micropigs, but the process is more efficient than repeating the full cloning procedure, and avoids potential health problems associated with cloning. Among the 20 second-generation gene-edited pigs, BGI has observed no adverse health effects, says Li.

He says that the micropigs have already proved useful in studies of stem cells and of gut microbiota, because the animals’ smaller size makes it easier to replace the bacteria in their guts. They will also aid studies of Laron syndrome, a type of dwarfism caused by a mutation in the human GHR gene. The decision to sell the pigs as pets surprised Lars Bolund, a medical geneticist at Aarhus University in Denmark who helped BGI to develop its pig gene-editing programme, but he admits that they stole the show at the Shenzhen summit. “We had a bigger crowd than anyone,” he says. “People were attached to them. Everyone wanted to hold them.”

They could meet a preexisting demand. In the United States, for instance, reports have surfaced of people who wanted a porcine lap pet, but were disappointed when animals touted as ‘teacup’ pigs weighing only 5 kilograms grew into 50-kilogram animals. Genetically-edited micropigs stay reliably small, the BGI team says.

But gene editing will not solve other drawbacks of pet pigs, says Crystal Kim-Han, who runs a rescue operation for abandoned pigs near Las Vegas, Nevada. For instance, if the animals are locked up in an apartment with no place to root or dig, they can become destructive. She also expects micropigs to have additional medical problems, similar to pets created by selective breeding. “What happens down the road when these animals need care?” she asks.

Some researchers think that dogs or cats will be next up for genetic manipulation. Scientists and ethicists agree that gene-edited pets are not very different from conventional breeding — the result is just achieved more efficiently. But that doesn’t make the practice a good idea, says Jeantine Lunshof, a bioethicist at Harvard Medical School in Boston, Massachusetts, who describes both as “stretching physiological limits for the sole purpose of satisfying idiosyncratic aesthetic preferences of humans”.

Dana Carroll, a gene-editing pioneer at the University of Utah in Salt Lake City, adds: “I can certainly imagine resistance to manipulating dogs, even though all of the current breeds are the result of selective breeding by humans.”

Daniel Voytas, a geneticist at the University of Minnesota in Saint Paul, hopes that any buzz over gene-edited pets does not hamper progress in developing gene-editing techniques for alleviating human disease and creating new crop varieties. “I just hope we establish a regulatory framework — guidelines for the safe and ethical use of this technology — that allows the potential to be realized,” he says.  “I worry that pet mini pigs distract and add confusion to efforts to achieve this goal.”

Nature 526, 18 (01 October 2015) doi:10.1038/nature.2015.18448  Nature  Original web page at Nature


* Success combating multi-resistant bacteria in stables

Multi-resistant bacteria represent a major problem not only in hospitals but also in animal husbandry. A study of the University Bonn describes how a farmer successfully eliminated these pathogens entirely from his pig stable. However, the radical hygiene measures taken in this case can only be applied in individual cases. Nevertheless, the work has yielded a number of recommendations — not only for farms but also for hospitals. The study appeared in the Journal of Applied and Environmental Microbiology.

Today some farms are implementing measures more frequently found in an operating theater: To enter the stable, employees have to change clothes. Before and after visiting the stables, hands must be cleaned thoroughly. Newly purchased animals are quarantined immediately. Particularly careful farmers arrange regular microbiological screens for resistant bacteria for themselves and their staff.

The purpose of these measures is to prevent the spread of dangerous pathogens — in particular multi-drug-resistant bacteria. Under certain circumstances these bacteria are dangerous, because infections are difficult to treat with antibiotics. Two major problems are posed by methicillin resistant Staphylococcus aureus (MRSA), and certain intestinal bacteria which produce extended-spectrum beta-lactamases (ESBL). Even the strictest precautions against these bacteria are often not 100 percent successful, because these pathogens are found not only in humans and animals but also on walls and even in the air of the stable. In a previous study, researchers at the University of Bonn found MRSA on every fifth pig, and an ESBL rate of 30 percent.

For the first time, researchers have successfully demonstrated that multi-resistant bacteria can be eradicated from a stable. “But these radical steps can only be implemented in very few cases,” says the agronomist Dr. Ricarda Schmithausen of the University of Bonn. As part of the study, the stables of the farmer were completely renovated and an additional new stable was built. The measures were accompanied by a multi-level disinfection process.

This would have been impossible during the daily routine. The farmer had planned a conversion of his farming system and therefore had previously slaughtered his entire herd and then restocked with pigs. The newly purchased animals were tested randomly to prevent the introduction of new resistant bacteria. The measures were successful, according to Dr. Schmithausen: “Today, two years after decontamination, the farm is still ESBL-free. MRSA, unfortunately, was a different story: Only two days later another MRSA variant was detected. Presumably, the new MRSA bacteria were introduced by one of the animals. In spite of all tests this cannot be avoided.” Nevertheless, the health of the herd has improved significantly. As a result, the use of antibiotics is hardly necessary any more.

MRSA are first and foremost pathogenic for humans and are largely harmless for animals. Previous studies by the University of Bonn have shown that farmers carry multi-resistant bacteria more often than the general population — as a result of their close contact with animals. The colonisation remains mostly asymptomatic for farmers. However, it can be dangerous, if the pathogens are transmitted to immuno-compromised patients in hospitals.

The agronomist and physician Dr. Ricarda Schmithausen defends the farmers. “Most cooperating farmers are very well informed and act very responsibly concerning this issue by implementing high hygiene standards” she emphasizes. The risk that MRSA and ESBL-E bacteria will spread further can be minimized through normal measures but cannot be reduced to zero. “Hospitals and livestock farms fight the same problems,” she says. “Both sides can learn from each other — hospitals could, for example, screen inpatients more consistently for multi-resistant bacteria. Science Daily  Original web page at Science Daily


Prevalence of hepatitis E virus infection in pigs at the time of slaughter, United Kingdom, 2013

Since 2010, reports of infection with hepatitis E virus (HEV) have increased in England and Wales. Despite mounting evidence regarding the zoonotic potential of porcine HEV, there are limited data on its prevalence in pigs in the United Kingdom. We investigated antibody prevalence, active infection, and virus variation in serum and cecal content samples from 629 pigs at slaughter. Prevalence of antibodies to HEV was 92.8% (584/629), and HEV RNA was detected in 15% of cecal contents (93/629), 3% of plasma samples (22/629), and 2% of both (14/629). However, although HEV is prevalent in pigs in the United Kingdom and viremic pigs are entering the food chain, most (22/23) viral sequences clustered separately from the dominant type seen in humans. Thus, pigs raised in the United Kingdom are unlikely to be the main source of human HEV infections in the United Kingdom. Further research is needed to identify the source of these infections.

Hepatitis E virus (HEV) that infects humans is composed of 4 genotypes (G1–4), each with a different geographic distribution and host range. Although G1 and G2 infect humans only, G3 and G4 infect humans and animals. HEV G3 and G4 are distributed worldwide, with G3 most commonly infecting both humans and pigs in Europe. From the observed incidence of acute HEV infection in blood donors, it is clear that HEV G3 infection in humans in England is far more common than previously thought. Realistic estimates are >100,000 infections annually.

Public Health England instituted enhanced surveillance of HEV infections in England and Wales in 2003 and identified a recent and marked increase in the number of patients seeking treatment for HEV infections. In 2013, a total of 691 cases were identified, of which 477 (69%) were considered indigenous (occurring in persons who had not traveled outside England and Wales). Sequencing of strains from these acutely infected persons has identified an emergent phylogenetic cluster of HEV G3 infection in humans, which is likely to represent a zoonosis acquired through the consumption of undercooked meat (B. Said, pers. comm.).

In an early study in the United Kingdom of porcine samples archived during 1991–2001, antibodies to HEV were detected in 85.5% of 256 samples tested. More recent studies across Europe indicate that many pig herds show evidence of HEV G3 infection. A transient viremia in pigs is associated with dissemination of HEV into muscle and other tissues. A recent UK study found HEV RNA in 6 of 63 pork sausages tested, of which 5 were in a single batch of 11, and a case−control study in England and Wales showed that human consumption of processed pork products is associated with an increased risk of acquiring HEV. It has long been considered plausible that the persistence of viremia in infected pigs up to the time of slaughter could provide a potential vehicle for zoonotic transmission to humans. We conducted surveillance of pigs at slaughter to investigate the epizoology of HEV in the United Kingdom and the extent of infection at the time pigs enter the food chain. Emerging Infectious Diseases Original web page at Emerging Infectious Diseases


* Super-muscly pigs created by small genetic tweak

Belgian Blue cattle are hulking animals that provide unusually large amounts of prized, lean cuts of beef, the result of decades of selective breeding. Now, a team of scientists from South Korea and China says that it has created the porcine equivalent using a much faster method.

These ‘double-muscled’ pigs are made by disrupting, or editing, a single gene — a change that is much less dramatic than those made in conventional genetic modification, in which genes from one species are transplanted into another. As a result, their creators hope that regulators will take a lenient stance towards the pigs — and that the breed could be among the first genetically engineered animals to be approved for human consumption.

Jin-Soo Kim, a molecular biologist at Seoul National University who is leading the work, argues that his gene edits merely speed up a process that could, at least in principle, occur through a more natural route. “We could do this through breeding,” he says, “but then it would take decades.”

No genetically engineered animal has been approved for human consumption anywhere in the world, owing to fears of negative environmental and health effects. Fast-growing transgenic Atlantic salmon have languished in regulatory limbo for 20 years with the US Food and Drug Administration.

Kim and his colleagues are part of a growing band of researchers who hope that gene editing, which can be used to disable — or knock out — a single gene, will avoid this. Reports of gene-editing applications in agriculture include the creation of hornless cattle. (Horns make the animals difficult to handle and are currently burned off in a painful procedure.) Researchers have also engineered pigs that are immune to African swine fever virus.

Key to creating the double-muscled pigs is a mutation in the myostatin gene (MSTN). MSTN inhibits the growth of muscle cells, keeping muscle size in check. But in some cattle, dogs and humans, MSTN is disrupted and the muscle cells proliferate, creating an abnormal bulk of muscle fibres.

To introduce this mutation in pigs, Kim used a gene-editing technology called a TALEN, which consists of a DNA-cutting enzyme attached to a DNA-binding protein. The protein guides the cutting enzyme to a specific gene inside cells, in this case in MSTN, which it then cuts. The cell’s natural repair system stitches the DNA back together, but some base pairs are often deleted or added in the process, rendering the gene dysfunctional.

The team edited pig fetal cells. After selecting one edited cell in which TALEN had knocked out both copies of the MSTN gene, Kim’s collaborator Xi-jun Yin, an animal-cloning researcher at Yanbian University in Yanji, China, transferred it to an egg cell, and created 32 cloned piglets. Kim and his team have not yet published their results. However, photographs of the pigs “show the typical phenotype” of double-muscled animals, says Heiner Niemann, a pioneer in the use of gene-editing tools in pigs who is at the Friedrich Loeffler Institute in Neustadt, Germany. In particular, he notes, they have the pronounced rear muscles that are typical of such animals.

Yin says that preliminary investigations, show that the pigs provide many of the double-muscled cow’s benefits — such as leaner meat and a higher yield of meat per animal. However, they also share some of its problems. Birthing difficulties result from the piglets’ large size, for instance. And only 13 of the 32 lived to 8 months old. Of these, two are still alive, says Yin, and only one is considered healthy.

Rather than trying to create meat from such pigs, Kim and Yin plan to use them to supply sperm that would be sold to farmers for breeding with normal pigs. The resulting offspring, with one disrupted MSTN gene and one normal one, would be healthier, albeit less muscly, they say; the team is now doing the same experiment with another, newer gene-editing technology called CRISPR/Cas9. Last September, researchers reported using a different method of gene editing to develop new breeds of double-muscled cows and double-muscled sheep (C. Proudfoot et al. Transg. Res. 24, 147–153; 2015).

Because gene editing is a relatively new phenomenon, countries have only just started to consider how to regulate it in agricultural plants and animals. There are some signs that government agencies will view it more leniently than they do conventional forms of genetic modification: regulators in the United States and Germany have already declared that a few gene-edited crops fall outside of their purview because no new DNA has been incorporated into the genome. But Tetsuya Ishii, who studies international biotechnology regulation at the Hokkaido University in Sapporo, Japan, and who has done an international comparison on GM regulations, says that gene editing will raise increasing alarm as it progresses in animals.

Kim hopes to market the edited pig sperm to farmers in China, where demand for pork is on the rise. The regulatory climate there may favour his plan. China is investing heavily in gene editing and historically has a lax regulatory system, says Ishii. Regulators will be cautious, he says, but some might exempt genetic engineering that does not involve gene transfer from strict regulations. “I think China will go first,” says Kim.

Nature 523, 13–14 (02 July 2015) doi:10.1038/523013a  Nature  Original web page at Nature


MRSA contamination found in supermarket sausages and minced pork in UK

A survey carried out earlier this year has found the first evidence of the ‘superbug’ bacteria Methicillin-Resistant Staphylococcus aureus (MRSA) in sausages and minced pork obtained from supermarkets in the UK. However, researchers stress that this does not pose a significant immediate risk to the public. In February, a team of researchers funded primarily by the Medical Research Council (MRC) bought and analysed a total of 103 (52 pork and 51 chicken) pre-packaged fresh meat products, labelled as being of UK farm origin, from supermarkets in five different locations across in England.

All of the meat products were frozen at -20?°C and sent to the Department of Veterinary Medicine at the University of Cambridge for testing. After thawing, researchers disinfected the exterior packaging before removing the meat. They then tested a 10g sample of meat from each packet and screened for MRSA. Two of the pork samples — one from sausages, one from minced pork — tested positive for MRSA; the sausage sample contained two strains of the bacteria.

In collaboration with the Wellcome Trust Sanger Institute an analysis of the genetic make-up of the bacteria and confirmed the presence of antibiotic resistant genes. The analysis showed that the bacteria belonged to a type of MRSA known as LA-MRSA CC398, which has emerged over the last few years in continental Europe, particularly in pigs and poultry, but was not previously believed to be widely distributed in the UK.

In many countries, LA-MRSA CC398 represents an occupational risk for those in close contact with livestock, particularly pigs and veal calves. Humans in contact with pigs (farm workers, abattoir workers and veterinarians, etc.) have significantly higher rates of the bacteria in their nasal carriage, according to epidemiological studies, for example. Other studies have revealed an association between clinical disease resulting from LA-MRSA CC398 infection and recent contact with pigs or pig farms. As with other MRSA, this type may be responsible for serious illness following wound or surgery site infections, although many people will carry MRSA on their skin or in their noses without showing signs of disease.

The researchers stress that adequate cooking (heating above 71°C) and hygienic precautions during food preparation should minimise the likelihood of transmission to humans via contaminated pork. However, they argue that the discovery of MRSA in pork identifies a potential way that the bacteria can spread from farms to the wider population.

While human contamination of carcasses or meat products in the abattoir or at the meat packing plant may occur, there is good evidence that these isolates are of animal origin — possibly through the use of antibiotics to treat or control infection in livestock. As the tests use a highly sensitive method of detection of bacterial contamination, the numbers of MRSA bacteria present may be low. The researchers say that as the two infected samples contained processed pork (sausages and minced pork), they cannot rule out that the meat packing plants from which the MRSA from this study originated also handle imported meat. If this were the case, it is conceivable that cross-contamination might have occurred between non-UK to UK sourced meat.

Dr Mark Holmes from the Department of Veterinary Medicine at the University of Cambridge says: “This is the first time that MRSA has been detected in retail meat products in the UK. The public should not be overly worried by this as sensible food precautions and good hygiene should prevent its spread. It’s also usually pretty harmless and only causes health problems if it infects someone in poor health or gets into a wound. “However, this does suggest that MRSA is established in our pig farms and provides a possible route of transmission from livestock, through those in direct contact with pigs, into the wider population.”

Dr Des Walsh, Head of Infections and Immunity at the MRC, added: “Studies like this are crucial not just to reveal concerns to human health through contaminated livestock, but to show resistance to antibiotics is a problem growing far beyond just humans. To win the fight against antimicrobial resistance, we need an all hands on deck approach, and that’s why we’ve teamed up with leading experts in biological, social and others sciences in a joint initiative designed to find new solutions, fast.”  Science Daily  Original web page at Science Daily


* Swine farming a risk factor for drug-resistant staph infections, study finds

Swine farmers are more likely to carry multidrug-resistant Staphylococcus aureus (S. aureus or “staph”) than people without current swine exposure, according to a study conducted by a team of researchers from the University of Iowa, Kent State University, and the National Cancer Institute. The study, published online in the journal Clinical Infectious Diseases, is the largest prospective examination of S. aureus infection in a group of livestock workers worldwide, and the first such study in the United States.

S.aureus is a type of bacteria commonly found on the skin as well as in the noses and throats of people and animals. About 30 percent of the U.S. population carries these bacteria, which can cause a range of skin and soft tissue infections. Although most infections are minor, S. aureus can sometimes cause serious infections. Increasingly, drug-resistant strains of S. aureus are emerging, including methicillin-resistant (MRSA), tetracycline-resistant (TRSA), or multidrug-resistant (MDRSA) strains. And while previous studies have shown that certain strains of S. aureus are often associated with swine, cattle, and poultry exposure, little is known about livestock-associated staph carriage and infection in the United States.

The study authors note the research helps keep farmers safe by raising awareness about a potential health issue in swine operations. S. aureus does not present an economic concern for swine farmers since pigs generally are unaffected by staph infections.

S. aureus does not typically make pigs sick, but they can act as carriers and transmit the bacterium to farmers,” says Tara Smith, corresponding author on the study. “While carriage of S. aureus isn’t itself harmful, individuals who harbor the bacterium in their nose, throat, or on their skin are at risk of developing an active staph infection, and they can also pass the bacterium to other family or community members. Individuals who may be immunocompromised, or have existing conditions such as diabetes, are especially at risk from staph infections.”

For the study, the researchers followed a group of 1,342 Iowans, including individuals with livestock contact and a community-based comparison group, for 17 months. The participants were recruited from 53 of Iowa’s 99 counties and lived in rural areas or small towns. Nose and throat swabs were collected from participants at the beginning of the study to determine if they carried S. aureus. Participants who experienced skin infections during the study period also were assessed for S. aureus. Overall, 26 percent of the participants carried S. aureus. However, the investigators found that farmers with livestock exposure, particularly swine exposure, were more likely to carry MDRSA, TRSA, and livestock-associated S. aureus than those who weren’t exposed to livestock.

“Current swine workers were six times more likely to carry multidrug-resistant S. aureus than those study participants without current swine exposure,” says Smith. The study is based on research that Smith, currently an associate professor at Kent State University, conducted while she was a faculty member at the UI College of Public Health. “Swine workers are also at risk of becoming infected with these organisms,” Smith adds. “One hundred and three potential S. aureus infections were reported, and included infections with livestock-associated strains of this bacterium.” There currently is no method to prevent or eliminate carriage of S. aureus in animals or their human caretakers, meaning constant re-exposure and possibly transmission can occur between livestock and farm workers. Those workers can then pass staph to their family or community members.

“Iowa ranks third nationally in overall livestock production and first in swine production,” notes Smith. “Transmission of staph between pigs and farmers and into the broader community could complicate efforts to control S. aureus transmission statewide, and have effects nationally due to the travel of pigs and people carrying these bacteria.  Science Daily  Original web page at Science Daily


Dose-response relationship between antimicrobial drugs and livestock-associated MRSA in pig farming

The farming community can be a vehicle for introduction of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in hospitals. During 2011–2013, an 18-month longitudinal study aimed at reducing the prevalence of LA-MRSA was conducted on 36 pig farms in the Netherlands. Evaluations every 6 months showed a slight decrease in MRSA prevalence in animals and a stable prevalence in farmers and family members. Antimicrobial use, expressed as defined daily dosages per animal per year, decreased 44% during the study period and was associated with declining MRSA prevalence in pigs. MRSA carriage in animals was substantially higher at farms using cephalosporins. Antimicrobial use remained strongly associated with LA-MRSA in humans regardless of the level of animal contact. A risk factor analysis outlined potential future interventions for LA-MRSA control. These results should encourage animal and public health authorities to maintain their efforts in reducing antimicrobial use in livestock and ask for future controlled intervention studies.

In 2005, sequence type (ST) 398 of methicillin-resistant Staphylococcus aureus (MRSA) emerged in Europe with proven transmission between pigs and humans. Since then, pigs, veal calves, and (to a lesser extent) poultry were increasingly found to harbor livestock-associated MRSA (LA-MRSA).

ST398 is widely spread across Europe, and ≈70% of pig farms in the Netherlands test positive. After transfer to humans, it can be introduced into hospitals and the community. In 2011, ST398 accounted for 39% of all new MRSA detected through screening of patients in the Netherlands.

To our knowledge, no intervention studies have been undertaken to assess the efficacy of MRSA-reducing measures on farms. Trade of animals is a major risk factor for introducing MRSA into a negative herd. Larger herds have been associated with higher antimicrobial use . Antimicrobial use could not be identified as a clear determinant for MRSA. Transmission dynamics within herds vary by animals’ ages and phase of production, potentially leading to endemicity.

In 2006, the European Union banned the use of antimicrobial drugs as growth promoters. In the Netherlands the most noticeable change started in 2010, when the government set objectives for a 50% reduction in antimicrobial use by 2013 and 70% by 2015, compared with 2009. This policy was combined with benchmarking of farms, and later veterinarians, to identify persistently high users of antimicrobial drugs. As part of this national program, farm treatment and health plans have to be drafted and reviewed annually, which has resulted in an almost 60% reduction for the major livestock industry sectors. Against the background of nationwide reduction of antimicrobial use, during 2011–2013, we evaluated MRSA carriage changes in pigs and humans and study the effect of introduction of an additional range of preventive measures on MRSA carriage in animals, and humans living and/or working on the farms. Read more:  Emerging Infectious  Diseases  Original web page at Emerging Infectious Diseases


Dose-response relationship between antimicrobial drugs and livestock-associated MRSA in pig farming

The farming community can be a vehicle for introduction of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in hospitals. During 2011–2013, an 18-month longitudinal study aimed at reducing the prevalence of LA-MRSA was conducted on 36 pig farms in the Netherlands. Evaluations every 6 months showed a slight decrease in MRSA prevalence in animals and a stable prevalence in farmers and family members. Antimicrobial use, expressed as defined daily dosages per animal per year, decreased 44% during the study period and was associated with declining MRSA prevalence in pigs. MRSA carriage in animals was substantially higher at farms using cephalosporins.

Antimicrobial use remained strongly associated with LA-MRSA in humans regardless of the level of animal contact. A risk factor analysis outlined potential future interventions for LA-MRSA control. These results should encourage animal and public health authorities to maintain their efforts in reducing antimicrobial use in livestock and ask for future controlled intervention studies. In 2005, sequence type (ST) 398 of methicillin-resistant Staphylococcus aureus (MRSA) emerged in Europe with proven transmission between pigs and humans. Since then, pigs, veal calves, and (to a lesser extent) poultry were increasingly found to harbor livestock-associated MRSA (LA-MRSA).

ST398 is widely spread across Europe, and ≈70% of pig farms in the Netherlands test positive. After transfer to humans, it can be introduced into hospitals and the community. In 2011, ST398 accounted for 39% of all new MRSA detected through screening of patients in the Netherlands. To our knowledge, no intervention studies have been undertaken to assess the efficacy of MRSA-reducing measures on farms. Trade of animals is a major risk factor for introducing MRSA into a negative herd. Larger herds have been associated with higher antimicrobial use. Antimicrobial use could not be identified as a clear determinant for MRSA. Transmission dynamics within herds vary by animals’ ages and phase of production, potentially leading to endemicity.

In 2006, the European Union banned the use of antimicrobial drugs as growth promoters. In the Netherlands the most noticeable change started in 2010, when the government set objectives for a 50% reduction in antimicrobial use by 2013 and 70% by 2015, compared with 2009. This policy was combined with benchmarking of farms, and later veterinarians, to identify persistently high users of antimicrobial drugs. As part of this national program, farm treatment and health plans have to be drafted and reviewed annually, which has resulted in an almost 60% reduction for the major livestock industry sectors. Against the background of nationwide reduction of antimicrobial use, during 2011–2013, we evaluated MRSA carriage changes in pigs and humans and study the effect of introduction of an additional range of preventive measures on MRSA carriage in animals, and humans living and/or working on the farms. Read more:  Emerging Infectious Diseases  Original web page at Emerging Infectious Diseases


Pig-borne disease most likely jumped into humans when rearing practices changed

Almost every pig carries harmless strains of the S. suis bacterium — such strains are known as ‘commensal’ strains. However, a more virulent group of strains of the bacteria also exist, which cause disease in pigs worldwide and are a major driver of antibiotic use for prevention. Increasingly, this group of strains is also implicated in serious human diseases such as meningitis and septicaemia. In order to understand the genetic basis of disease in S. suis, an international study, led by the Bacterial Respiratory Diseases of Pigs-1 Technology (BRaDP1T) consortium, examined the genomes of 375 clinical samples from pigs and humans from the UK and Vietnam and combined these with data already published on 15 S. suis genome sequences and draft genomes from around the world. They found that the commensal strains and disease-causing strains differed genetically; in particular, the disease-causing strains have between 50 and 100 fewer genes than the commensal strains.

Dr Lucy Weinert from the Department of Veterinary Medicine at the University of Cambridge, first author of the study, says: “It seems that the loss of genes is associated with causing disease. This is something we see quite often in bacteria, but for reasons that are unclear. One possibility is that the missing genes are those that hinder the function of newly-acquired virulence factors in the genomes.” By examining the S. suis‘s ‘tree of life’ — which looks at how the bacteria have evolved over time — the researchers were able to show that the emergence of a group of strains causing meningitis in pigs and the human form of the disease dates back to the 1920s, when pig production was intensified with the introduction of wide-scale indoor rearing of meat-producing pigs in larger groups, supported by government schemes that favoured larger producers with regular throughput. However, despite having jumped the species barrier from pig to human, the bacteria do not appear to have adapted to infect humans.

“A group of more virulent strains seem to have emerged at around the time the pig industry changed, and it is these strains that mostly cause disease in pigs and humans,” says Professor Duncan Maskell, Head of the School of the Biological Sciences at Cambridge. “Human S. suis disease in the West is extremely rare, but is seen more frequently in south east Asia. It is most likely spread to humans through poor food hygiene practices or other environmental factors. This emphasises the importance of monitoring such practices and putting policies in place to reduce the risk of the spread of infections between species.”  Science Daily  Original web page Science Daily


* An inside look at the first pig biobank

Boar 1339 was genetically engineered to have diabetes; its body parts, now in the Munich MIDY-PIG Biobank in Germany, are freely available to researchers. First out is a kidney: its dark red fades to beige as it is washed of its blood. The pancreas, harder to find amid the tangle of inner organs, is rushed on to dry ice. Speed is essential because tissues degrade after death — and each detail counts in this autopsy.

The precious organs belong to Boar 1339, which, for 3.5 years, had lived a normal pig’s life on the farm of a German university, despite the diabetes it was born with. Earlier this month, the animal was killed, and the body parts placed in the service of science, as part of a growing movement to maximize the scientific benefits of every animal used in research. Thousands of tiny tissue and fluid samples from the boar’s 226-kilogram body now sit in the newly constructed Munich MIDY-PIG Biobank in Germany — the world’s first systematic repository of tissue from a large, genetically engineered, non-human animal.

The biobank, part of Munich’s Ludwig Maximilian University (LMU), houses tissue taken from throughout the body and from pigs of different ages. It is designed to help diabetes researchers to discover the molecules and mechanisms involved in the long-term complications of the disease, including the degeneration of small blood vessels and nerves, heart and kidney disease, and blindness. These develop over a lifetime, and are poorly understood. “We are more similar to pigs than we like to think, so this resource will be very valuable,” says diabetes researcher Patrik Rorsman at the University of Oxford, UK. The samples are freely available to researchers anywhere in the world, who need only pay for the postage. As pressure grows to reduce the number of animals used in research, biobanks are becoming attractive because they allow teams working on different organs and aspects of the disease to use the same animal. “Biobanking means that no part of the animal is wasted,” says LMU geneticist and veterinary surgeon Eckhard Wolf, who launched the pig biobank.

Only a few animal biobanks have so far been built, and most are for mice. Pigs, although more expensive to house and breed, could be more useful because of their larger size and the greater similarity of their physiology and metabolism to those of humans. To create the pig biobank, scientists used genetic engineering and cloning techniques to create animals with a damaged gene called MIDY, which means that they need a daily insulin injection. The animals were then bred with healthy pigs so that, on average, half of the second-generation litters had diabetes and the other half were healthy, and thus able to serve as experimental controls. The 12th addition to the bank from this process, Boar 1339 was already anaesthetized when it arrived in the cavernous autopsy room of the 101-year-old veterinary school in a leafy suburb of Munich. Waiting for the pig was a team of 25 veterinary surgeons and technicians, gowned up, masked and alert at parallel dissection tables.

A hoist raised the pig by its hind legs and pathologists injected the animal with a lethal dose of anaesthetic. Then, in swift, precision choreography, the team moved in with their knives, cleavers, hammers and pincers. They removed organs, muscles, nerves and more, and transferred the tissues to the tables at which the waiting dissectors set about their complicated sampling process, strictly following an 80-page protocol. “We don’t want to complete a super-sophisticated sampling and then realize we forgot to weigh the liver,” says Andreas Blutke, one of the chief pathologists at the LMU. The chopping, hacking and puncturing are loud; the concentration of the workers keeps the background noise to a murmur. The whole process takes a mere 2 hours 15 minutes. Because the cells in any organ are of different sizes, shapes and orientations, and are unevenly distributed, the team takes numerous samples using different methods to ensure that the whole organ is appropriately represented. The system is so sophisticated that it gives researchers a three-dimensional anatomical reconstruction of the exact cell types.

Crucially, the researchers divide each sample and preserve the portions in different ways, each optimized for either structural or molecular analysis. This allows both types of analysis to be done on the same sample. “I think this is the only service which allows you to do molecular profiling and cellular anatomy from the same sample,” says Wolf. As soon as Rorsman heard about the biobank, he saw its benefit. He suspects that the long-term complications of diabetes are caused by changes in a particular molecule in the cells of several different tissues. Material from the biobank will allow him to confirm that he is on the right track, he says, before he obtains samples from human biobanks, which takes a long time because of ethical constraints. Herbert Tempfer, a diabetes researcher at the University of Salzburg in Austria, is already analysing samples of tendons — notoriously fragile in people with diabetes — from the biobank.

Others want to know how similar pig diabetes is to the human disease. Immunologist Åsa Hidmark at the University of Heidelberg in Germany made the three-hour journey to Boar 1339’s dissection to cut samples of skin from its trotter. She hopes to discover that the nerve endings in the outer layer have been lost, as happens in people with diabetes. The ultimate value of the bank will depend on how much it is used — and there are no guarantees. Despite its collection of 42 tissues taken from 940 mouse lines, a mouse biobank at the Wellcome Trust Sanger Institute near Cambridge, UK, has so far received only 50 or so requests for material. “There is a lack of awareness of its value,” says Jacqui White, who leads this Sanger mouse-autopsy project. Wolf plans to extend his biobank to other genetic pig models as they are developed. Next in line are probably pigs engineered to have Duchenne muscular dystrophy. A sow implanted with a cloned genetically modified embryo is now pregnant.

Nature 519, 397–398 (26 March 2015) doi:10.1038/519397a  Nature  Original web page at Nature


Comparison of porcine epidemic diarrhea viruses from Germany and the United States, 2014

Since 2013, highly virulent porcine epidemic diarrhea virus has caused considerable economic losses in the United States. To determine the relation of US strains to those recently causing disease in Germany, we compared genomes and found that the strain from Germany is closely related to variants in the United States. Porcine epidemic diarrhea (PED) is an acute and highly contagious enteric disease of swine that results in severe enteritis, diarrhea, vomiting, and dehydration. Porcine epidemic diarrhea virus (PEDV), the causative agent, is an enveloped, positive single-stranded RNA virus that belongs to the family Coronaviridae, genus Alphacoronavirus.

The disease was first recognized in Europe in 1971 and has thereafter caused high economic losses, particularly in Asia. In May 2013, a highly virulent PEDV variant emerged in the United States; explosive epidemics on swine farms affected pigs of all ages, resulting in a mortality rate of up to 95% among suckling pigs. Since then, outbreaks have occurred in 30 US states, causing very high economic losses, and the disease threatens to spread. The involved viruses cluster together with isolates from China from 2011 and 2012. Apart from these highly virulent strains, a PEDV variant from the United States (strain OH851) that affected sows instead of younger animals and caused milder disease was recently described.

The effect of PED in the United States has unsettled pig farmers and veterinarians worldwide; studies have been recently initiated to elucidate the situation in Europe. Despite the history of PED outbreaks in Europe, little is known about currently circulating virus strains and their effect; information about the phylogeny of recent strains and their relation to the outbreak strain in the United States is lacking.

Read more:  Emerging Infectious Diseases  Original web page at Emerging Infectious Diseases


New drug-delivery capsule may replace injections

Given a choice, most patients would prefer to take a drug orally instead of getting an injection. Unfortunately, many drugs, especially those made from large proteins, cannot be given as a pill because they get broken down in the stomach before they can be absorbed. To help overcome that obstacle, researchers at MIT and Massachusetts General Hospital (MGH) have devised a novel drug capsule coated with tiny needles that can inject drugs directly into the lining of the stomach after the capsule is swallowed. In animal studies, the team found that the capsule delivered insulin more efficiently than injection under the skin, and there were no harmful side effects as the capsule passed through the digestive system. “This could be a way that the patient can circumvent the need to have an infusion or subcutaneous administration of a drug,” says Giovanni Traverso, a research fellow at MIT’s Koch Institute for Integrative Cancer Research, a gastroenterologist at MGH, and one of the lead authors of the paper, which appears in the Journal of Pharmaceutical Sciences. Although the researchers tested their capsule with insulin, they anticipate that it would be most useful for delivering biopharmaceuticals such as antibodies, which are used to treat cancer and autoimmune disorders like arthritis and Crohn’s disease. This class of drugs, known as “biologics,” also includes vaccines, recombinant DNA, and RNA. “The large size of these biologic drugs makes them nonabsorbable. And before they even would be absorbed, they’re degraded in your GI tract by acids and enzymes that just eat up the molecules and make them inactive,” says Carl Schoellhammer, a graduate student in chemical engineering and a lead author of the paper. Scientists have tried designing microparticles and nanoparticles that can deliver biologics, but such particles are expensive to produce and require a new version to be engineered for each drug. Schoellhammer, Traverso, and their colleagues set out to design a capsule that would serve as a platform for the delivery of a wide range of therapeutics, prevent degradation of the drugs, and inject the payload directly into the lining of the GI tract. Their prototype acrylic capsule, 2 centimeters long and 1 centimeter in diameter, includes a reservoir for the drug and is coated with hollow, stainless steel needles about 5 millimeters long. Previous studies of accidental ingestion of sharp objects in human patients have suggested that it could be safe to swallow a capsule coated with short needles. Because there are no pain receptors in the GI tract, patients would not feel any pain from the drug injection.

To test whether this type of capsule could allow safe and effective drug delivery, the researchers tested it in pigs, with insulin as the drug payload. It took more than a week for the capsules to move through the entire digestive tract, and the researchers found no traces of tissue damage, supporting the potential safety of this novel approach. They also found that the microneedles successfully injected insulin into the lining of the stomach, small intestine, and colon, causing the animals’ blood glucose levels to drop. This reduction in blood glucose was faster and larger than the drop seen when the same amount of glucose was given by subcutaneous injection. “The kinetics are much better, and much faster-onset, than those seen with traditional under-the-skin administration,” Traverso says. “For molecules that are particularly difficult to absorb, this would be a way of actually administering them at much higher efficiency.” “This is a very interesting approach,” says Samir Mitragotri, a professor of chemical engineering at the University of California at Santa Barbara who was not involved in the research. “Oral delivery of drugs is a major challenge, especially for protein drugs. There is tremendous motivation on various fronts for finding other ways to deliver drugs without using the standard needle and syringe.” This approach could also be used to administer vaccines that normally have to be injected, the researchers say. The team now plans to modify the capsule so that peristalsis, or contractions of the digestive tract, would slowly squeeze the drug out of the capsule as it travels through the tract. They are also working on capsules with needles made of degradable polymers and sugar that would break off and become embedded in the gut lining, where they would slowly disintegrate and release the drug. This would further minimize any safety concern.  Science Daily  Original web page at Science Daily


* Iberian pig genome remains unchanged after five centuries

A team of Spanish researchers have obtained the first partial genome sequence of an ancient pig. Extracted from a sixteenth century pig found at the site of the Montsoriu Castle in Girona, the data obtained indicates that this ancient pig is closely related to today’s Iberian pig. Researchers also discard the hypothesis that Asian pigs were crossed with modern Iberian pigs. The study, published in Heredity, sheds new light on evolutionary aspects of pig species, and particularly on that of the Iberian breed, considered to be representative of original European Mediterranean populations. The study was led by Miguel Pérez-Enciso, ICREA researcher at Universitat Autònoma de Barcelona (UAB) and at the Centre for Research in Agrigenomics (CRAG). Researchers from the Institute of Evolutionary Biology (CSIC-Pompeu Fabra University) and the National Centre for Genome Analysis (CNAG) also participated in the study. The sample dates approximately from the years 1520 to 1550 and is previous to the introduction of Asian pigs in Europe, which were later crossed with local European breeds which are the origin of today’s international pig species. The sample pig is contemporary to the beginning of America’s colonisation. “Although it is a very fragmented sample, the gene sequence offers very interesting information,” Miguel Pérez-Enciso says. “First of all, we know it is not a white pig because it is missing a duplicated KIT gene which would make it this colour. This coincides with the majority of paintings from that period, in which the animal was always painted black or in reddish tones. We were also able to establish that it is very closely related to today’s Iberian pig species, and specifically to the ‘Lampiño del Guadiana’ strain. We could say that the Iberian pig is very similar to the pigs which existed in the sixteenth century and no great changes have been registered in this genome. Therefore, more studies will be needed before we are able to distinguish the modern species from the older ones.” The study indicates that the pig was a domestic pig, given that the sequence presents a series of markers typical of domestic pigs and which are very rare or absent in wild boars (the precursor animals to the domestic pig); moreover, this coincides with the historical registers of the castle, which clearly indicates that pig breeding was an important castle activity. Nevertheless, there is also evidence of occasional crossbreeding between wild boars and ancient pigs, as has happened between wild boars and Iberian pigs. “This close relation between the Iberian pig, the European boar and the ancient pig confirms, as stated in previous studies, that crossbreeding between the Asian pig and modern Iberian pigs did not exist or was insignificant,” Miguel Pérez-Enciso points out. The study also compared the ancient pig sample with the genome of modern pigs of different breeds, including ‘Creole’ pigs, which are presumably the descendents of the animals Spanish colonizers brought to America. Researchers demonstrate that this hypothesis is incorrect and that there is very little remaining of those first Spanish animals in today’s creole pigs, which were crossbred mainly with international pig breeds.  Science Daily  Original web page at Science Daily


* Piglet health: A better understanding of the immune response to intestinal parasites

Parasitologists from the University of Veterinary Medicine of Vienna are closer to understanding the disease process behind porcine neonatal coccidiosis. The disease affects piglets during the first days of their life and can cause heavy diarrhea in the animals. The parasite Cystoisospora suis damages the intestinal mucosa to such a degree that it threatens the growth and survival of the pigs. The researchers have now analysed the immune response to the infection. The results were published in the journal Parasite Immunology. Porcine neonatal coccidiosis is a serious parasitic infection of young piglets that severely damages the intestinal mucosa, leading to diarrhea and reduced nutritional intake. As the infection reduces animal growth, and because secondary infections can result in increased mortality, the disease is responsible for substantial economic losses at affected pig farms. “The developing immune system of neonatal piglets is not yet mature enough to deal with the parasites. For this reason, an infection shortly after birth results in weakened intestinal tissue with appropriate consequences. By comparison, Cystoisospora suisis absolutely harmless for adult pigs and their mature immune systems,” explains first author Simone Gabner. Immune cells grow more quickly in the intestines of infected piglets than in healthy ones. Scientists from the Institute of Parasitology at the Vetmeduni Vienna investigated how the developing immune system of piglets responds to an infection with Cystoisospora suis. For the purpose of the study, 25 animals aged three days were infected and observed in comparison with another 26 healthy, non-infected animals. The researchers analysed various different immune cells in the intestines of both groups over the course of the first days of life. High levels of so-called gamma delta T cells, a type of cell that recognizes tissue damage and activates the immune system, were found in infected piglets as early as four days after infection. Cytotoxic T-cells were detected eleven days after an infection. These are responsible for the cell death of infected cells and appear to have an immunologic memory function with regard to porcine neonatal coccidiosis. Both types of T cells were detected significantly earlier in infected piglets than in non-infected animals. In healthy piglets, the T cells begin to settle in the intestine from about the third week of life. “Before this, we didn’t know which T cells played a part in porcine neonatal coccidiosis. Now we also know at which point they appear in the course and development of the disease. Their exact role in the intestines of the animals, however, remains unclear,” Gabner says. “Cystoisospora suis affects epithelial cells in the intestine and destroys the natural barrier against pathogens. This makes secondary infections likely. We still don’t know whether the T cells reduce the overall damage to the intestinal mucosa or if they perhaps cause the damage to the intestinal cells.” Gabner and her colleagues also researched various receptors of the innate immune system in the piglets as well as signalling substances which play a part in the inflammatory response. Just four days after infection, the researchers found increased expression of certain pathogen receptors (TLR-2 and NOD2) and signalling molecules involved in inflammatory reactions (TNF-α) in the intestine of the infected animals. The parasite thus triggers the activation of the immune system. “Our research shows which signalling pathways could be involved. The immune response possibly begins even earlier. This is something to be investigated in future studies. We are one step closer to better understanding the disease,” says Gabner. Previous studies by the research group showed that protective antibodies against porcine neonatal coccidiosis are transferred to the piglets through the sow’s milk directly after birth. Sows that had been exposed to the pathogen produced the respective antibodies from which the piglets could then benefit. In a follow-up study, the researchers went one step further. They deliberately infected sows with the parasites during gestation in order to increase the antibody levels in the maternal animals. The aim was to supply the piglets with as many antibodies from the mother’s milk during their first days of life as possible. This “milk vaccination” was a success. The piglets of infected sows exhibited a less severe development of the disease than piglets of non-infected sows. The more antibodies a sow transferred to its piglets, the weaker the symptoms exhibited by the piglets.  Science Daily  Original web page at Science Daily


* Swine-to-Human Transmission of Influenza A(H3N2) Virus at Agricultural Fairs, Ohio, USA, 2012

Agricultural fairs provide an opportunity for bidirectional transmission of influenza A viruses. We sought to determine influenza A virus activity among swine at fairs in the United States. As part of an ongoing active influenza A virus surveillance project, nasal swab samples were collected from exhibition swine at 40 selected Ohio agricultural fairs during 2012. Influenza A(H3N2) virus was isolated from swine at 10 of the fairs. According to a concurrent public health investigation, 7 of the 10 fairs were epidemiologically linked to confirmed human infections with influenza A(H3N2) variant virus. Comparison of genome sequences of the subtype H3N2 isolates recovered from humans and swine from each fair revealed nucleotide identities of >99.7%, confirming zoonotic transmission between swine and humans. All influenza A(H3N2) viruses isolated in this study, regardless of host species or fair, were >99.5% identical, indicating that 1 virus strain was widely circulating among exhibition swine in Ohio during 2012. In the United States during 2012, approximately 300 cases of human infection with influenza A(H3N2) variant (H3N2v) virus were reported; they resulted in 16 hospitalizations and 1 death. The variant designation (swine-origin influenza A virus infecting humans) of these cases must be acknowledged because interspecies transmission of influenza A virus plays a substantial role in the evolution of influenza A viruses that infect swine and humans. Genomic reassortment resulting in novel influenza A viruses can occur in swine because they are susceptible hosts for avian and human strains as well as strains endemic among swine. Thus, swine play a critical role in the ecology and emergence of influenza A viruses that affect human health, as illustrated by the emergence of the 2009 pandemic influenza virus (influenza A[H1N1]pdm09 virus), a reassortant virus with origins that have been traced to influenza A viruses circulating among swine in North America and Eurasia. Bidirectional transmission of influenza A viruses between swine and humans is facilitated by unique swine–human interfaces such as agricultural fairs, where swine from multiple sources commingle with human exhibitors and visitors. In 2007, novel influenza A viruses, including those of nonhuman origin, became part of the National Notifiable Diseases Surveillance System, and before 2012, outbreaks of variant influenza A virus were reported only occasionally in the medical literature; these cases were frequently linked to human exposure to swine at agricultural fairs. Epidemiologic investigations by public health officials into human cases of influenza virus subtype H3N2v infection that occurred during 2012 concluded that swine exposure at agricultural fairs was the primary source of the viruses. Emerging Infectious Diseases  Original web page at Emerging Infectious Diseases


* It does not always need to be antibiotics: healthy pig breeding

Scientists found a way to reduce the application of antibiotics in pig breeding by using antimicrobial peptides. The results of the study have just been published in the scientific online-journal PLOS ONE. Researchers investigated the application of antimicrobial peptides (AMP) as substitutes for antibiotics in liquid sperm preservation. Firstly they were able to show that AMPs fight bacteria effectively in test tubes. Then they showed that two of the investigated AMPs suppressed bacterial growth in liquid preserved semen preparations if combined with a small amount of the antibiotic “gentamicin.” The sperm quality was not impeded by this addition. Bacteria are extremely adaptable which can lead to an increasing resistance against antibiotics. This causes big problems for breeders when using artificial insemination, the method most commonly used in assisted reproductive technology in pig production worldwide. Freshly retrieved boar ejaculates always contain bacteria. These germs are detrimental to the quality as well as the longevity of liquid preserved sperm, with dire, negative consequences for fertility. The addition of antibiotics to liquid semen is required by law and facilitates an inhibition of bacterial growth. However, many types of bacteria quickly develop resistances to the usually applied antibiotics. Hence it is important to look for new antimicrobial alternatives. Scientists from the German Leibniz Institute for Zoo and Wildlife Research (IZW) investigated the effect of antimicrobial peptides in cooperation with the Leibniz Institute of Molecular Pharmacology (FMP) and the Institute for Reproduction of Farm Animals Schoenow e.V. (IFN). These molecules are naturally occurring amino acid compounds, are toxic for bacteria and can be found in nearly all organisms as a first defence against germs. For this study, synthetic cationic antimicrobial peptides were produced. “Antimicrobial peptides do not offer a complete alternative for traditional antibiotics in liquid sperm preservation, but allow a substantial reduction in their concentration,” explains Dr Karin Müller from the IZW. “This is a benefit for people as well, as the occurrence of resistance will be reduced if fewer antibiotics are used.” Additional application possibilities are conceivable, outlines Dr Margitta Dathe from the FMP. “Antimicrobial peptides could be used for the preservation of other cells as well. Furthermore special AMPs for the treatment of superficial infections could be developed.”  Science Daily Original web page at Science daily


Gene therapy creates biological pacemaker

Gene therapy could soon join the electronic pacemaker as a treatment for a weak heart. By inserting a specific gene into heart-muscle cells, researchers can restore a normal heart rate in pigs — at least temporarily. Electronic pacemakers restore regular function to slowing and arhythmic hearts by using electricity to stimulate their beating — a function usually performed by the sinoatrial node, a cluster of a few thousand cardiac cells that signal the heart to pump at a regular rate. Although implanted pacemakers are widely used, they require an invasive surgery to be installed, carry the risk of infection, and can set off alarms during airport security checks. To overcome these limitations, a team led by Eduardo Marbán, a cardiologist at Cedars-SinaiMedicalCenter in Los Angeles, California, sought to coax heart cells outside the sinoatrial node to keep the beat using a less invasive approach. The findings are reported today in Science Translational Medicine. In 12 pigs, the team mimicked a fatal human heart condition in which electrical activity cannot spread through the heart from the sinoatrial node, forcing other, weaker parts of the heart to take over. The researchers used high-frequency radiowaves to destroy the pigs’ natural pacemaking cells in the sinoatrial node. As a result, the animals’ average heart rate slowed to about 50 beats per minute, compared to the normal rate of 100 or more beats per minute. Then the scientists injected the pigs’ hearts with a virus that had been modified to carry a pig gene, Tbx18, involved in heart development. Within a day, heart cells infected with the virus began expressing a variety of pacemaking genes and pumping the heart at a normal rate. The animals maintained this steady beating for the two-week study period, whether resting, moving or sleeping. Marbán says that his method is simpler than other biological approaches to steady irregularly beating hearts, such as inducing cardiac muscle cells to a pluripotent state, then coaxing them to differentiate into pacemaker cells. But he cautions that the effect of the gene therapy may be temporary. Over time, the body’s immune system is likely to recognize the virus used to deliver Tbx18 to the heart and attack infected cells. Marbán’s team is now monitoring pigs that have received the gene-therapy treatment for several months to see how long the pacemaker effect persists.

But even if the treatment’s effects are limited, it could still prove useful, says Marbán. For example, if a person’s electronic pacemaker becomes infected and must be removed, a biological pacemaker could keep the heart pumping steadily until the infection clears and a new device can be implanted. The gene-therapy approach could also help fetuses with heart defects, as well as children who quickly outgrow implanted pacemakers or people for whom surgery is too risky. “I think it’s a truly creative idea,” says Ira Cohen, a cardiac electrophysiologist at StonyBrookUniversityMedicalCenter in New York. He would like to see the therapy tested in dogs, whose average heart rate is more similar to that of humans’ 60-100 beats per minute.. Marbán says that the group is now talking to the US Food and Drug Administration about developing a human trial, which he says could be just two to three years away. Nature doi:10.1038/nature.2014.15569  Nature  Original web page at Nature


Genetic variation among African Swine fever genotype II viruses, Eastern and Central Europe

African swine fever virus (ASFV) was first reported in eastern Europe/Eurasia in 2007. Continued spread of ASFV has placed central European countries at risk, and in 2014, ASFV was detected in Lithuania and Poland. Sequencing showed the isolates are identical to a 2013 ASFV from Belarus but differ from ASFV isolated in Georgia in 2007. African swine fever (ASF) is a devastating disease of domestic and wild suids, and there is no vaccine to protect against the disease. ASF is caused by a DNA arbovirus, African swine fever virus (ASFV), belonging to the family Asfaviridae; the virus genome is 170–192 kb long. ASF is endemic in sub-Saharan countries and in Sardinia (Italy) and has become more prevalent in Russia and the Caucasus region since its spread from eastern Africa to Georgia (in the Caucasus region) in 2007. The ongoing spread of ASFV to adjacent eastern European countries, such as Ukraine and Belarus, and the uncontrolled spread of the disease in Russia have placed the bordering areas of the European Union at high risk for the introduction of ASFV. In early 2014, the first cases of ASF in the European Union were reported; the cases occurred in 4 wild boars in areas of Lithuania and Poland that border the eastern European country of Belarus. To further our knowledge of the epidemiology and spread of ASFV, we determined the virus sequences of the ASFVs isolated in Poland and Lithuania by using international standardized procedures and by the analysis of an additional ASFV genome marker region characterized by the presence of tandem repeat sequences (TRSs). We report the genetic characterization of these ASFVs. Read more:  Emerging Infectious Diseases

July 8, 2014  Original web page at Emerging Infectious Diseases


Human stem cells successfully transplanted, grown in pigs

One of the biggest challenges for medical researchers studying the effectiveness of stem cell therapies is that transplants or grafts of cells are often rejected by the hosts. This rejection can render experiments useless, making research into potentially life-saving treatments a long and difficult process. Now, researchers at the University of Missouri have shown that a new line of genetically modified pigs will host transplanted cells without the risk of rejection. “The rejection of transplants and grafts by host bodies is a huge hurdle for medical researchers,” said R. Michael Roberts, Curators Professor of Animal Science and Biochemistry and a researcher in the Bond Life Sciences Center. “By establishing that these pigs will support transplants without the fear of rejection, we can move stem cell therapy research forward at a quicker pace.” In a published study, the team of researchers implanted human pluripotent stem cells in a special line of pigs developed by Randall Prather, an MU Curators Professor of reproductive physiology. Prather specifically created the pigs with immune systems that allow the pigs to accept all transplants or grafts without rejection.

Once the scientists implanted the cells, the pigs did not reject the stem cells and the cells thrived. Prather says achieving this success with pigs is notable because pigs are much closer to humans than many other test animals. “Many medical researchers prefer conducting studies with pigs because they are more anatomically similar to humans than other animals, such as mice and rats,” Prather said. “Physically, pigs are much closer to the size and scale of humans than other animals, and they respond to health threats similarly. This means that research in pigs is more likely to have results similar to those in humans for many different tests and treatments.” “Now that we know that human stem cells can thrive in these pigs, a door has been opened for new and exciting research by scientists around the world,” Roberts said. “Hopefully this means that we are one step closer to therapies and treatments for a number of debilitating human diseases.”  Science Daily

July 8, 2014  Original web page at Science Daily


Pathology of US porcine epidemic diarrhea virus strain PC21A in gnotobiotic pigs

To understand the progression of porcine epidemic diarrhea virus infection, we inoculated gnotobiotic pigs with a newly emerged US strain, PC21A, of the virus. At 24–48 hours postinoculation, the pigs exhibited severe diarrhea and vomiting, fecal shedding, viremia, and severe atrophic enteritis. These findings confirm that strain PC21A is highly enteropathogenic. A highly contagious coronavirus that causes porcine epidemic diarrhea (PED) was first reported in the United States in May 2013 inIowa. Since then, the virus—porcine epidemic diarrhea virus (PEDV)—has spread rapidly nationwide. PEDV (family Coronaviridae, genus Alphacoronavirus) was previously reported only in Europe and Asia. The first US outbreaks caused a high number of deaths among suckling pigs and, as a consequence, substantial economic losses. Results of PEDV pathogenesis studies using the prototype European PEDV strain, CV777, were reported in the 1980s. Strain CV777 infections caused intestinal villous atrophy with substantially reduced ratios of villous height to crypt depth (VH:CD). Pathogenic features of CV777 are similar to those observed for Asian PEDV strains that circulated in the 1990s. To understand the progression of PEDV infection, we studied the pathogenesis of the newly emerged US strain, PC21A. Emerging Infectious Diseases

April 15, 2014  Original web page at Emerging Infectious Diseases