Genetic heterogeneity of HIV-1 in Greece

The aim of this study was to detect and determine the genetic variation of HIV-1 in Greece and to analyze the phylogenetic relationships and transmiss ion dynamics of identified variants. Eighty-six blood samples from HIV-1 se roconverted patients of different risk groups were collected from the AIDS clinic, AHEPA Hospital, Thessaloniki, Greece. Retroviral DNA was extracted from uncultured peripheral blood mononuclear cells. HIV-1 DNA sequences enc oding a 500-bp fragment of the gp120 C2-C3 region were amplified from each study subject, and they were genetically subtyped by heteroduplex mobility assay and DNA sequencing. Genetic distances and phylogenetic relationships of DNA sequences were estimated using PHYLIP software. Our results revealed that 82 out of 86 (95%) subjects carried subtype B sequences, while four ( 4.7%) carried subtype A sequences. Subtype A in Greek individuals not havin g traveled abroad was documented. An average of intrasubtype B genetic dive rgence of 15% was noted. Our findings demonstrate the presence of at least two genetic subtypes of HIV-1 in northern Greece - subtype B and subtype A. The predominant subtype is subtype B, which was transmitted into Greece by multiple sources. Our observations lend support to the argument that the d istribution of HIV-1 subtypes is determined by founder effects or other pro cesses rather than any tropism for particular cell types or mode of transmi ssion. (C) 2000 Editions scientifiques et medicales Elsevier SAS.