Analysis of RT Sequences of Subtype C HIV-Type 1 Isolates from Indian Patients at Failure of a First-Line Treatment According to Clinical and/or Immunological WHO Guidelines

The reverse transcriptase (RT) sequences of HIV-1 subtype C isolates from Indian patients at failure (according to WHO clinical or immunological criteria) of a first-line treatment including d4T/AZT-3TC-NVP/EFV were compared to those of HIV-1 isolates from naive patients and analyzed for drug resistance mutations (DRMs), which were interpreted according to ANRS and Stanford algorithms. All viruses were of subtype C. We have observed a decrease of the polymorphism at positions 36 and 214 of RT while D121Y, V179I, and Q217E could be new DRMs. Numerous crucial DRMs to NRTIs and NNRTIs could be recorded including TAMs of pathway 1 and K65R. According to both algorithms, the accumulation of DRMs may induce resistance to second-line NRTIs including tenofovir.