Genotypic resistance mutations to antiretroviral drugs in treatment-naive HIV/AIDS patients living in Liaoning Province, China: baseline prevalence and subtype-specific difference.

To examine the prevalence of drug resistance mutations among treatment-naive HIV/AIDS patients living in Liaoning province in China, the HIV-1 pol gene from plasma of 91 seropositive treatment-naive patients was amplified and sequenced. Three patients (3.3%) had an M46I amino acid substitution in the protease (PR) gene that decreased susceptibility to IDV, RTV, and NFV and one patient (1.1%) had an M184I amino acid substitution in the reverse transcriptase (RT) gene that confers high-level resistance to 3TC and FTC. Minor mutations were detected in high frequency in the PR gene. The frequencies of minor mutations to protease inhibitors (PI) were I93L (71.4%), L63P (62.6%), V77I (62.6%), M36I/V (33.0%), A71T/V (22.0%), K20R (6.6%), G16E (6.6%), and L10I (5.5%). The relatedness between subtypes and the frequencies of amino acid substitutions in PR were observed; 63P, 77I, and 71V/T were found in HIV-1 subtype B'/B, 16E, 36I, 20R/I, and 82I in non-B, except for CRF07_BC, 10I in subtype A, and 93L in non-A. Although the primary resistance of HIV-1 to antiretroviral drugs is low among the treatment-naive HIV-1 patients living in Liaoning province, the surveillance and monitoring of drug-resistant HIV-1 should be implemented regularly because of the increased access to antiretroviral therapy in China.