Molecular characterization of VP7 gene of human rotaviruses from Bangladesh.

This study was carried out during July 2005-June 2006, to characterize rotaviruses circulating in Bangladeshi children less than 5 years attended a peri-urban hospital. The proportion of rotavirus diarrhea was 39.5%. Genotype G2 was dominant (45.5%) followed by G1 (24.8%), G12 (9.6%), G9 (8.5%), and G4 (2.1%). G2 were mainly in combination with P[4], G1 and G9 with P[8], and G12 with P[6]. Phylogenetically Bangladeshi G1, G2, and G12 were closely related with the respective types from India, whereas Bangladeshi G9s of lineage III were with strains from Belgium and Australia. A G9 strain of lineage IV was clustered with strains from Sri Lanka and Turkey. Compared with prototype rotaviruses, Bangladeshi strains showed several amino acid substitutions at the antigenic sites of VP7. This study showed that the generation of diverse strains continued as evidenced by long G2, short G1 and G9 strains, and various combinations of G and P types.