Serological and molecular analysis of serotype O foot-and-mouth disease virus isolated from disease outbreaks in India during 1987-91.
Foot-and-mouth disease virus (FMDV) type O outbreaks have been reported frequently in vaccinated cattle in India. Twenty-five field isolates, recovered from outbreaks in vaccinated and unvaccinated cattle between 1987 and 1991, were analyzed in relation to the vaccine strain (R2/75) by complement fixation, serum neutralization and partial nucleotide sequencing of the VP1 gene. These sequences were compared with the viral sequences in GenEMBL database. Although the Indian type O viruses were close to the European type O1 viruses, they constituted a separate group of type O FMDVs. One of the field viruses, isolated from an outbreak in vaccinated cattle and designated as BAK/90, showed significant serological and nucleotide sequence variations from the vaccine strain. Phylogenetic analysis showed that the BAK/90 and R2/75 viruses belong to separate subgroups. The other isolates were found to be serologically related to both the BAK/90 and the vaccine strain. The BAK/90 strain gave broader antigenic coverage, showed better immunogenicity, and yielded larger amounts of 146S particles in suspension cultures as compared with R2/75. Taken together, these results favour inclusion of the BAK/90 strain in the vaccine to provide adequate protection against the field variants of type O FMDV currently circulating in India.
Singh
M
M
Indian Veterinary Research Institute, Hebbal, Bangalore, India.
Mohan
B M
BM
Suryanarayana
V V
VV
D000595:Amino Acid Sequence; D000818:Animals; D005537:Aphthovirus / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D036022:Capsid Proteins; D002460:Cell Line; D006224:Cricetinae; D004279:DNA, Viral; D004196:Disease Outbreaks; D005536:Foot-and-Mouth Disease / Q000453:epidemiology / Q000517:prevention & control / Q000821:virology*; D014644:Genetic Variation; D006168:Guinea Pigs; D007194:India; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012703:Serotyping
D036022:Capsid Proteins; D004279:DNA, Viral; C442501:VP1 protein, Foot-and-mouth disease virus