Phylogenetic characterization of foot-and-mouth disease virus recovered from mithuns and yaks in India

The yak and mithun husbandry in India is confronted with several challenges including the prevalence of foot-and-mouth disease(FMD). The present study was initiated to investigate FMD out breaks in semi-domesticated mithun and yak population in various parts of India. A total of 64 clinical samples (vesicle/tongue/foot epithelium/fluid) from mithun and 6 from yak were collected from suspected FMD outbreaks during 2008–2013. Supernatants of the homogenized clinical samples were tested in a serotype discriminating antigen detection ELISA and ELISA-negative samples were further subjected to multiplex reverse transcription-polymerase chain reaction (mRT-PCR). A total of 45 mithun samples and only 1 yak sample were found positive for serotype O in antigen detection ELISA. A total of 12 ELISA-negative samples from mithun and 4 from yak were later on found positive for serotype O in mRT-PCR. The phylogenetic analysis based on VP1 genome indicated the involvement of both O/ME-SA/PanAsia and O/ME-SA/Ind 2001 lineages of serotype O in those outbreaks. These viruses were genetically similar to those contemporary virus isolates responsible for FMD in domestic livestock indicating a situation of virus sharing among different species of domestic and semi-domestic animals. Thus, mithuns and yaks should be synchronously considered and targeted along with cattle for the effective control of the disease in the country.