Genetic variability of HIV-1 protease from Nigeria and correlation with protease inhibitors drug resistance

In Nigeria, the most populous country in Africa, the characterization of HI V-1 strains has been limited. In this study we evaluated the genetic divers ity of the protease coding region, one of the anti-retroviral therapy targe t, and investigated the presence of mutations related to resistance to HIV protease inhibitors. We analyzed samples collected during 1996 and all pati ents were anti-retroviral drug naives. Ten samples were evaluated by sequen cing of the protease gene. The majority, 80%, were classified as subtype A and the two others were unclassified-divergent strains, something in betwee n A and G subtypes. The gag region from these outliners were sequenced and the phylogenetic analysis classified them as subtype G. The protease amino acid consensus sequence of the Nigerian subtype A are in complete agreement with the consensus A differing from the USA subtype B consensus in 10 posi tions (L10V, I13V, K14R, I15V, K20I, M36I, R41K, P63L, H69K and L89M). The secondary substitutions associated with protease inhibitor resistance w ere observed in all Nigerian sequences at the positions L10V, M36I and L89M . The majority of sequence variation was concentrated in the interval betwe en aminoacids 70-90 where the protease substrate binding region is located.