The development and evaluation of a probe hybridization method for subtyping HIV type 1 infection in Uganda

We developed a method for large-scale screening of HIV-1 genotypic variation based on DNA probe hybridization. Nested PCR amplifications were performed to generate fragments in the env C2-V3 region and also in the gp41 region, which encompasses the immunodominant domain. The proviral DNA sequences were derived from 68 samples and phylogenetically analyzed. For comparison, the C2-V3 fragment was used in DNA probe hybridization to rapidly determine the infecting HIV subtype. The hybridizing probes were designed on the basis of the two most prevalent subtypes in Uganda, A and D. The results were compared to evaluate the feasibility of using this hybridization method for large-scale genotypic screening. Sequence analysis of the 68 amplified PCR fragments showed that 39 were subtype A and 29 were subtype D. The results of DNA hybridization to the amplified products with A and D subtype-specific probes were more than 90% concordant with the subtypes determined by sequence analysis. Our findings suggest that probe hybridization with subtype-specific probes is effective for large-scale screening of HIV-infected populations. Application of this method will significantly reduce the time needed for large, population-based investigations.