To investigate the distribution of subtypes of human immunodeficiency virus type 1(HIV-1)epidemic strains and the prevalence of primary drug resistance in the HIV infected individuals among men who have sex with men(MSM)population in Harbin from 2016 to 2017.

Peripheral blood samples with the antiretroviral therapy(ART)-naïve were collected from 60 newly diagnosed HIV-1 infected individuals in Harbin Infectious Diseases Hospital and the Fourth Affiliated Hospital of Harbin Medical University.RNA was extracted from the plasma.HIV-1 gag, pol, and int gene fragments were amplified by reverse transcription PCR and nested PCR, purified, and sequenced.Phylogenetic tree and subtype analysis were performed using Mega 6.0 software.The type and frequency of drug resistance mutations were analyzed using the Stanford HIV Drug Resistance Database.

50 gag gene sequences, 56 pol gene sequences, and 44 int gene sequences were successfully amplified.The subtype analysis showed that CRF01_AE, CRF07_BC, B subtypes, and unique recombinant forms (URF) accounted for 59.7% (34/57), 26.3% (15/57), 3.5% (2/57), and 10.5% (6/57), respectively.The drug resistance mutations were found in total of 7 samples (12.5%), among them the highest frequency of V179D/E/T was 8.75% (5/56) for non-nucleoside reverse transcription inhibitors.In addition, Q58E (1/56) and M46I (1/56) mutations which were resistance to protease inhibitors were also found.No resistance mutation sites to nucleoside reverse transcriptase inhibitors and integrase inhibitors were found.

Among the newly diagnosed HIV-1 infected individuals via MSM transmission route, the proportion of CRF01_AE subtypes is the highest, followed by CRF07_BC and other URF recombinant with CRF01_AE.The proportion of drug-resistant strains is higher and no drug resistance(DR) mutations to the integrase inhibitors was found.

Men who have sex with men; Human immunodeficiency virus; Virus subtype; Drug resistance mutation