Development of drug resistance among HIV-1 F1 sub-type patients with treatment failure

Results All the strains were found to belong to the F1 subtype. 65.4% of the patients presented resistance to at least one of the 3 antiretroviral classes of used drugs (NRTI, NNRTI and PIs ), while 15.4% were resistant to 2 classes and only 7,7% were resistant to all 3 antiretroviral classes. The most frequent substitutions of amino acids in reverse transcriptase gene were from TAM2’s ("thymidine analogue mutations”): D67N, K70R, T215F, K219Q/E-mutations that confer resistance to NRTI and K103N, Y181C/I associated with primary resistance to NNRTI. Only 23% from the patients presented substitutions associated with major resistance to PI , the most frequent: I47V, G48 G/V; I54V, V82A, that confer phenotypic resistance to regimens that include ritonavir as a booster. As a surprise a series of minor and accessories mutations were present in the protease gene (ordered in decreased frequency: L10V, M36I; L63T, K20M/R).