ANTIGENIC AND GENOMIC DIVERSITY OF HUMAN ROTAVIRUS VP4 IN 2 CONSECUTIVE EPIDEMIC SEASONS IN MEXICO

In the present investigation we characterized the antigenic diversity of the VP4 and VP7 proteins in 309 and 261 human rotavirus strains iso lated during two consecutive epidemic seasons, respectively, in three different regions of Mexico. G3 was found to be the prevalent VP7 sero type during the first gear, being superseded by serotype G1 strains du ring the second season. To antigenically characterize the VP4 protein of the strains isolated, we used five neutralizing monoclonal antibodi es (MAbs) which showed specificity for VP4 serotypes P1A, P1B, and P2 in earlier studies. Eight different patterns of reactivity with these MAbs were found, and the prevalence of three of these patterns varied from one season to the next. The P genotype of a subset of 52 samples was determined by PCR Among the strains characterized as genotype P[4] and P[8] there were three and five different VP4 MAb reactivity patte rns, respectively, indicating that the diversity of neutralization epi topes in VP4 is greater than that previously appreciated by the genomi c typing methods.