Sequence analysis of recent Indian isolates of foot-and-mouth disease virus serotypes O, A and Asia 1 from clinical materials

Partial nucleotide sequences of 1D gene of 38 isolates of foot-and-mouth di sease virus (FMDV) of serotypes O, A and Asia 1 originating from various pa rts of India were determined. Field materials were subjected straight to RN A extraction, reverse transcription - PCR (RT PCR) and sequencing. Also 3 F MDV vaccine strains, IND R2/75 (serotype O), IND 63/72 (serotype Asia 1) an d IND 17/77 (serotype A) were included in the analysis. The seqences were c ompared mutually as well as with available corresponding sequences of other FMDV isolates, and their phylogenetic relationships were calculated. The d educed amino acid sequences showed that the serotype O isolates were relati vely conserved as compared to serotype Asia 1 or A isolates from India. In phylogenetic analysis, the serotype fl viruses clustered in two genotypes, one including the European vaccine strain (O1/K) and the other represented by the isolates from Bangladesh, India, Nepal and Turkey. The serotype Asia 1 viruses clustered in two groups of single genotype where the prototype s train from Pakistan (PAIL 1/54) formed one group and the other was formed b y the isolates from Bangladesh, Bhutan, India, Israel and Nepal. In serotyp e A viruses three well-differentiated genotypes were observed. The isolates from Azerbaijan, Bangladesh, Malaysia and India formed the first genotype. The second genotype was formed by isolates from Iran, Saudi Arabia and Tur key, while two recent Iranian isolates represented the third genotype. In I ndia, the prevalence of at least one genotype could be identified in each s erotype. This evolutionary clustering of isolates from the neighbor countri es is not surprising, since these countries share border with India. The ge netic relatedness between sequences of isolates from India and those from d istant places is indicative of spread of the virus between the countries. O f importance is the fact that clinical materials proved useful for rapid ge neration of sequences and subsequent studying of molecular epidemiology of the disease.