Replicative capacity of Middle East respiratory syndrome coronavirus (MERS-CoV) was assessed in cell lines derived from livestock and peridomestic small mammals on the Arabian Peninsula. Only cell lines originating from goats and camels showed efficient replication of MERS-CoV. These results provide direction in the search for the intermediate host of MERS-CoV. Coronaviruses (CoV) in the genera Alphacoronavirus and Betacoronavirus (order Nidovirales, family Coronaviridae, subfamily Coronavirinae) infect a broad range of mammals, including humans. The human CoVs (HCoVs) HCoV-HKU1, HCoV-229E, HCoV-NL63, and HCoV-OC43 typically cause mild to moderate respiratory tract infection; however, the disease course can be more severe in a minority of patients. In 2002–2003, an epidemic of severe lower respiratory tract infection with a case-fatality rate of ≈10% was caused by severe acute respiratory syndrome (SARS)–CoV. In 2012, another CoV associated with severe respiratory disease emerged on the Arabian Peninsula and was termed Middle East respiratory syndrome (MERS)–CoV.
Both SARS-CoV and MERS-CoV are zoonotic viruses, and their presumed origin is in bats. SARS-related CoVs were identified in Rhinolophus spp. bats in China and Europe, and MERS-related CoVs were found in Pipistrellus bats in Europe and in Neoromicia bats in South Africa. As with SARS-CoV, it is expected that MERS-CoV might be transmitted to humans by an intermediate animal host, and neutralizing antibodies against MERS-CoV have been found in Arabian camels originating from Oman, Spain, and Egypt. We investigated replication of MERS-CoV in cell lines of the most abundant mammalian livestock species and representative peridomestic small mammals on the Arabian Peninsula. To estimate MERS-CoV permissiveness of cell cultures derived from these animals, we compared MERS-CoV replication and infectious virus production with that in bat- and primate-derived cells known to be permissive for MERS-CoV. The MERS-CoV receptor dipeptidyl peptidase 4 (DPP-4) is expressed in epithelial cells of the lung and kidney, and patients with MERS-CoV consistently show severe involvement of both organs; thus, we focused on lung and kidney cells in potential animal hosts.
Emerging Infectious Diseases
January 21, 2014
Original web page at Emerging Infectious Diseases