GENETIC-CHARACTERIZATION OF HIV TYPE-1 FROM MIGRANT WORKERS IN 3 SOUTH-AFRICAN GOLD-MINES

The phylogenetic relationships between 44 HIV-1 isolates from 43 infec ted subjects employed by three adjacent South African gold mines were investigated. The patients were migrant workers originating from rural areas of South Africa and the neighboring countries of Lesotho, Botsw ana, Swaziland, and Mozambique. Proviral HIV-1 DNA was subtyped using a heteroduplex mobility assay (HMA) based on the 700-bp V3-V5 region o f the env gene. DNA sequence analysis was used to confirm the subtype designation and to determine phylogenetic relationships between isolat es. All 34 HIV-1 isolates were identified as env subtype C using both HMA and phylogenetic analysis. These isolates did not show a distinct phylogenetic relatedness based on the geographic origins of the migran t workers or show close homology to other subtype C sequences from sou thern Africa or India. However, five clusters of closely related seque nces were identified, mainly involving miners of disparate geographic origins, suggesting possible epidemiological linkage in these few case s. The characteristic tetrapeptide sequence, GPGQ, at the tip of the V 3 loop of subtype C viruses was conserved in the predicted amino acid sequences of most isolates. The heterogeneity of HIV-1 sequences among migrant workers in a mining cohort suggests multiple introductions of HIV-1 subtype C into this population that are not apparently linked t o the geographic origins of the patients.