title: Experimental evidence for competitive growth advantage of genotype VII over VI: implications for foot-and-mouth disease virus serotype A genotype turnover in nature.
abstract: In India, systematic genotype replacement has been observed for serotype A foot-and-mouth disease virus. After a decade of co-circulation of genotypes VI and VII, genotype VII emerged as the single dominant genotype since 2001. To derive possible explanations for such epochal evolution dynamics, in vitro intergenotype growth competition experiments involving both co- and superinfection regimes were conducted. Coinfection of BHK-21 cells demonstrated abrupt loss in the genotype VI viral load with commensurate increase in the load of genotype VII as measured by the genotype differentiating ELISA, RT-PCR and real-time RT-PCR. The superinfection dynamics was shaped by temporal spacing of infection, where the invading genotype VII took more number of passages than coinfection to eventually overtake the resident genotype VI. It was speculated that such superior replicative fitness of genotype VII could have been a possible factor for the ultimate dominance of genotype VII in nature.
authors.affiliation: Project Directorate on Foot and Mouth Disease, Indian Veterinary Research Institute Campus, Mukteswar-Kumaon, Nainital 263138, Uttarakhand, India.
authors.forename: J K
authors.initials: JK
authors.lastname: Mohapatra
authors.forename: S
authors.initials: S
authors.lastname: Subramaniam
authors.forename: N K
authors.initials: NK
authors.lastname: Singh
authors.forename: A
authors.initials: A
authors.lastname: Sanyal
authors.forename: B
authors.initials: B
authors.lastname: Pattnaik
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D019143:Evolution, Molecular; D005536:Foot-and-Mouth Disease / Q000821:virology*; D029544:Foot-and-Mouth Disease Virus / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D005838:Genotype; D012703:Serotyping; D015163:Superinfection / Q000821:virology; D019562:Viral Load; D010948:Viral Plaque Assay