Subtype distribution and drug resistance of HIV-1 in HIV infected pregnant women in Guangzhou

Objective To understand the subtype distribution and drug resistance of HIV-1 in HIV infected pregnant women in Guangzhou of Guangdong province.

Methods Plasma samples from pregnant women who were positive for HIV-1 were collected during 2009–2014 for the amplification of protease (PR) and reverse transcriptase (RT) gene segments with nested reverse transcription polymerase chain reaction (nested-PCR). HIV subtypes were determined through phylogenetic analysis and the drug resistance mutation (DRM) was analyzed with HIV Drug Resistance Database of Stanford University.

Results A total of 178 gene segments, including 10 from foreign cases, were successfully amplified. Significant difference in subtype distribution was observed between domestic cases and foreign cases (P＜0.001), the predominant subtypes were CRF01_AE (42.86%, 72/168) and CRF07_BC (31.55%, 53/168) in domestic cases and the predominant subtypes were C (30.00%, 3/10) and CRF01_AE (30.00%, 3/10) in foreign cases. The incidence rate of DRM was 12.36%.The upper low level resistant rates to any drug was 5.62% (10/178), and the resistant rates to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) were 2.81% (5/178), 1.12% (2/178) and 2.25% (4/178), respectively. Subtype C showed the highest DRM rate (50.00%, 3/6). DRMs were observed in 5 foreign cases and 3 cases were drug resistant. Six samples (3.37%) were predicted to be highly resistant to single class drug. No samples which were highly resistant to multi-class drugs were detected.

Conclusion Twelve HIV-1 subtypes were detected in HIV infected pregnant women in Guangzhou, the predominant subtypes were CRF01_AE and CRF07_BC. The DRM rate and drug resistant rate were low, but the strains with high resistance to PIs or NRTIs or NNRTIs were observed and the foreign cases had higher DRM rate and drug resistant rate.