Complete genomic analysis of a Bangladeshi G1P[8] rotavirus strain detected in 2003 reveals a close evolutionary relationship with contemporary human Wa-like strains

More than 120 variants of rotavirus strains with different VP7 (G type) and VP4 (P type) combinations are reported thus far. Among them Wa-like G1P8] rotaviruses are the most common human strains worldwide. However, characterization of their entire genome complement is limited to a few old prototype strains, and no complete genome data for any G1P8] strain isolated in the last decade are available. Both the currently licensed rotavirus vaccines Rotarix? and RotaTeq? possess the G1 and P8] specificities. Therefore, comprehensive genetic information of the currently circulating G1P8] strain is important to assess the impact of rotavirus vaccines on the circulating rotavirus strains. Here we report the complete genome sequence of a G1P8] rotavirus strain Dhaka16-03 isolated in 2003 from a Bangladeshi child hospitalized with severe diarrhea. Based on a full-genome classification system, Dhaka16-03 was shown to posses the typical Wa-like genotype constellation: G1-P8]-I1-R1-C1-M1-A1-N1-T1-E1-E1-H1. The strain was phylogenetically more closely related to contemporary human rotavirus strains (isolated in the 2000s) with a range of G and P-genotypes than to those of the prototype G1P8] strains. Since the vaccine strains are developed based on strains isolated several decades ago, it is important to know how much the vaccine strains differ from the currently circulating G1P8] and other Wa-like strains. Our complete genome characterization of a recent G1P8] strain will be helpful to assess the ongoing rotavirus vaccine trials and their implementation programs in the forthcoming years.