Genetic barriers of primary drug resistance mutations in 123 recombinant subtype strains of human immunodeficiency virus-1 / 中华传染病杂志

ABSTRACT

Objective To compare the genetic barriers to development of primary mutations related to drug resistance to protease inhibitors (PI), nucleioside reverse transcriptase inhibitors ( NRTI ), and non-nucleioside reverse transcriptase inhibitors ( NNRTI ) among human immunodeficiency virus (HIV)-1 CRF01_AE, CRF07_BC, and CRF08_BC strains, and to understand the difference of varying patterns of drug resistance related mutations within these subtypes. Methods One hundred and ninety naive HIV-positive subjects from Nanning City and Liuzhou City, Guangxi Zhuang Autonomous Region, were recruited. Peripheral blood samples were collected from all participants. HIV-1 RNAs were extracted from plasma, and the pol regions were amplified and sequenced. Sequences were subjected to phylogenetic analysis to determine the subtypes of HIV-1 isolates. Nucleotide transitions and transversions were counted for each primary mutation in these sequences. According to the phenomena that transitions occur on average 2. 5 times frequently than transversions, each transition was scored as 1, and each transversion scored as 2. 5. The sum of the scores for a particular substitution was calculated, and this value was taken as the genetic barrier to development of this mutation. Then, the differences of genetic barriers among the subtypes were assessed by Kruskal-Wallis test and Nemenyi test. Results A total of 123 sequences of CRF01_AE,CRF07_BC and CRF08_BC strains were selected. CRF08_BC had a lower genetic barrier for T/S69Dsubstitution than CRF01_AE and CRF07_BC (χ2 =107. 501, P＜0.01), while CRF01_AE and CRF07_BC had lower genetic barriers for V118I and L210W substitution than CRF08_BC. In addition,CRF07_BC had a decreased genetic barrier for V106M compared with CRF01_AE and CRF08_BC.Conclusions In the presence of the same selective pressure, subtypes CRF01_AE and CRF07_BC may be more likely to develop V118I and L210W substitution than CRF08_BC. However, CRF08_BC may be more likely to develop T/S69D substitution than CRF01_AE and CRF07_BC. Meanwhile, CRF07_BC may be easier to develop V106M substitution than CRF01_AE and CRF08_BC.