[Genetic characteristics of HIV-1 primary drug resistance-associated mutations in treatment-naive individuals in Liaoning province, 2004-2008].

Objective To investigate the HIV-1 drug resistance associated mutations and examine the susceptibility of HIV-1 with these mutations to antiretroviral in treatment-naive individuals in Liaoning province from 2004 to 2008. Methods RNA was extracted from 20 plasma samples of diagnosed untreated HIV-1-infected treatment-naive patients by drawing method. After the viral loading (VL) test,the protease and nucleoside reverse transcriptase coding regions were amplified by RT-PCR, nested PCR and sequence analysis directly. Levels of resistance and prevalence were evaluated according to the Stanford University HIV Drug Resistance Database's algorithm (http://hivdb. stanford, edu ). Results Among the 20 plasma samples,13 got PCR products because of their VL values higher than 1000 copies/ml. Meanwhile, the 13 samples got 65 sequences by using 5 primers each. Polymorphisms in subtype H and circulating recombinant forms (CRFs) CRF10_CD sequences were identified. An overall prevalence of 30. 8% (4/13) resistance to NNRTIs,7.7% (1/13) to PI and no NRTIs mutations were found. The most frequent substitutions (4/13) in the RT region at positions P225H, K238S, V179D, K238T and a major position L54S in PR implied to a multiple drug-resistance. A71V or L10V only,respectively,substitution in PR was found in 3 samples,but no any worse with drug sensitivity. Conclusion HIV-1 polymorphisms in subtype H and CRFs CRF10_CD sequences were identified circulating in Liaoning. A major mutation position I54S in PR implied that it would be the time to commence a higher level drug regimen. Key words: HIV-1;  HIV infections;  Multidrug resistance-associated proteins;  Mutation