Abstract

Vaishali S. Tatte and D. Shobha D. Chitambar

Genetic variability of rotaviruses circulating in Pune, India at the two time points was determined by
characterizing VP4 genes in 131 rotavirus strains detected in adolescent and adult cases of acute
gastroenteritis. The multiplex RT-PCR classified the VP4 genes in 73 P[4] (43.2%), 69P[8] (40.8%) and 27
P[6] (16.0%) genotypes. Sequencing and phylogenetic analysis revealed increase in the prevalence of
P[4]-5 and P[8]-2 and decline of P[8]-3 lineages in 2000s as compared to those identified in 1990s (92.8%
Vs 100%, 4.2% Vs 33.3% and 93.7% Vs 66.7%, respectively). The P[4]-1 and P[8]-4 lineages circulated at
low levels (7.1% / 2.1%) while presence of only P[6]-1 (100%) lineage was detected at both time. The
strains with different VP4 genotype specificities displayed 0.2 to 2.3% amino acid divergence. A
significant difference (P<0.01) in their association with common and nontypeable G strains was noted
between the two time points studied. This is the first report to describe the intragenotypic diversity in
the rotavirus VP4 genes from adolescent and adult patients of acute gastroenteritis from India. VP4
being one of the major protective antigens, monitoring the mutations in this protein would be crucial to
understand the evolutionary