Characterization of HIV-1 subtypes and drug resistance mutations among individuals infected with HIV in Georgia.

In order to describe HIV-1 subtypes and drug resistance mutations in Georgia, blood samples from 153 patients infected with HIV-1 collected from 2006 to 2008 were genotyped. Of these, 126 samples were from newly diagnosed, antiretroviral (ARV)-naïve patients and 27 from ARV-treated patients. Partial pol region sequences were used to identify drug resistance mutations and to conduct phylogenetic analysis for subtype determination. The results indicated that 138 (90.2%) patients harbored subtype A viruses, 11 (7.2%) carried subtype B virus, two subtype G (1.3%), one (0.6%) subtype F and one (0.6%) 03_AB recombinant. All subtype A strains clustered with the Former Soviet Union A (A FSU) subtype. Among patients with no prior exposure to ARVs, mutations associated with resistance were detected in five patients: three (2.4%) patients had reverse transcriptase (RT) inhibitor mutations and two other patients had the protease (PI) inhibitor associated mutation M46I. PI mutation V77I was found in 42 of subtype A isolates. Of 27 ARV-treated patients, 22 (81.5%) harbored at least one nucleoside reverse transcriptase inhibitors (NRTI), a non-NRTI (NNRTI) and/or a PI mutation. The most common NRTI resistance mutation was M184V/I (74.1%). Frequency of thymidine analog mutations was relatively low (25.9%). With regard to NNRTI mutations, G190S/A was the most frequent mutation, which might be a preferred mutations for subtype A. Georgia's HIV epidemic continues to be dominated by Subtype A FSU. The prevalence of transmitted drug resistance is low, but has the potential to increase with increasing use of ARVs.