Antigenic and molecular characterization of unusual rotavirus strains in Burkina Faso in 1999.

Thirty-six of 37 rotavirus strains recovered from the diarrheal stools of 166 children <3 years of age in Burkina Faso were characterized at both the antigenic and molecular levels. The rotavirus strains were confirmed by polyacrylamide gel electrophoresis; 30 displayed predominantly short electropherotype patterns, and 6 had a long RNA pattern. The strains were subgrouped by monoclonal antibody enzyme immunoassay for VP6 and were typed as subgroup I (29 of 30 short rotavirus strains) and subgroup II (5 of 6 long strains). The VP7 serotyping and genotyping showed that all 6 viruses with long electropherotype patterns were G1. The short strains were determined to be VP7 serotype G2 by reverse-transcription polymerase chain reaction (PCR) in 27 strains and nucleic acid sequencing of selected strains, although only 1 reacted with the G2-specific monoclonal antibodies. Finally, the short patterns were shown by the PCR genotyping method to be VP4 genotype P[6], and the long patterns were shown to be P[8]. The predominant strain found in Burkina Faso in this small study was an unusual G2P[6] strain that showed a short RNA electropherotype and VP6 subgroup I specificity and failed to react with a panel of G2-specific monoclonal antibodies.