ABSTRACT
Objective To analyze the genetic structure and recombination characteristics of a new-ly discovered HIV-1 unique recombinant strain in Yunnan Province. Methods During a test for drug-resist-ant HIV genotypes in Yunnan Province in 2016, a recombinant fragment was found in the pol region of a HIV-1 strain isolated from a patient. Two overlapping segments of the HIV-1 genome were amplified by RT-PCR, and then the products were sequenced. Recombination analysis was performed using RIP, jpHMM and SimPlot3. 5 software. A phylogenetic tree was constructed for homology analysis by Neighbor-joining method using MEGA6. 06 software. Results A nearly full-length HIV-1 gene sequence with 8590 bp in length was obtained. Breakpoint analysis indicated that the sequence consisted of CRF01_AE and fragments of B and C subtypes. CRF01_AE was used as the backbone with B and C subtype fragments inserted. The positions were 791 to 1171 for CRF01_AE, 1172 to 2652 for C subtype fragment, 2653 to 2977 for B subtype frag-ment, and 2978 to 9380 for CRF01_AE using HIV-1 HXB2 as the reference strain. Conclusions Some new strains formed by cross-recombination of CRF01_AE and B and C subtypes were discovered in Yunnan Province in recent years. It was found that the recombination pattern of the newly discovered strain was com-plex, suggesting that close attention should be paid to the changes in epidemic trends, which was of great im-portance to understand the current prevalence and epidemic trends of HIV-1.
ABSTRACT
Objective To investigate the subtypes distribution of human immunodeficiency virus (HIV)-1 epidemic strains and the characteristics of amino acid variation in different areas of Yunnan Province.Methods Totally 800 HIV/AIDS plasma specimens and epidemiological information were collected between 2012 and 2015 from 14 areas of Yunnan.Viral RNA was extracted and amplified using RT polymerase chain reaction (PCR).4.5 kb 5'halves fragments were obtained and directly sequenced.Subtypes of strains were identified by Genotyping,MEGA 6.06 and BLAST.Grouping was analyzed by location and subtype.Entropy software was used to analyze the difference of amino acid sequences between different groups according to the sampling location and subtypes to analyze the regional distribution and genetic variation of HIV-1 subtypes in Yunnan Province.Results Of the 800 plasma specimens,a total of 446 genomic sequences from 12 areas were successfully amplified and sequenced.After genotypes were identified,the subtypes of HIV-1 strains prevalent in Yunnan were CRF08_BC (58.3％),CRF01_AE (19.3％),CRF07_BC (11.6％),unknown recombinant forms (7.1％),B(B') (1.7％) and C (1.3％).The geographical distribution in Yunnan was analyzed.The CRF01_AE predominated in Dehong,Xishuangbarma and Wenshan.The CRF08_BC predominated in Lincang,Honghe and Puer (more than 70.0％) and CRF08_BC was prevalent in the other areas.But CRF07_BC in Kunming,Yuxi and Dali accounted for more than 20 ％.The constitutions of amino acid of three majors CRF08_BC,CRF01 _AE and CRF07_BC were different on 17,14 and 18 amino acid sites with statistical differences in the eastern and western regions of Yunnan Province (均P ＜ 0.05).Conclusions HIV-1 strains transmit and vary genetically in the province widely.The amino acid mutation sites of eastern and western strains are different.This difference represents that the same subtype strains in different geographical distribution vary on different genetic background and are selected by immune responses.The epidemic trends need to be closely monitored.
ABSTRACT
Objective To investigate the variations in the pol region of HIV-1 strain in treatment failed patients in Yunnan province's Dehong prefecture and Kunming. Methods Blood samples were collected from 139 patients who experienced treatment failure ( HAART treatment ＞ 1 years and HIV-1 RNA Viral load ＞ 1 000 copies/ml). HIV-1 RNA was extracted from plasma, and nested-PCR was performed for amplification of PR and RT genes on the HIV-1 pol region. The PCR products were then sequenced and submitted to Stanford HIV Drug Resistance Database for comparison. The evolution tree was built up with MEGA 4. 1 system, combined with patients' demographics. Results The most prevalent mutation in Kunming patients were T215F/N/Y/I, M41L/M, and T69G/N/I/S/A/D, the mutation rates were 39%(24/62), 27% (17/62) and 27% (17/62) , respectively, which were higher than the corresponding mutations in the Dehong prefecture [16% ( 11/69), 13% (9/69) and 9% (6/69)]. The rate differences were statistically significant ( x2 = 8.646, 4.242 and 7. 909, all P ＜ 0.05 ). The most common HIV-1 pol region subtype in the Dehong patients were CRF01_AE subtype (32%, 22/69), followed by C subtype (25% ,17/69), and B subtype ( 19%, 13/69). Major subtypes in Kunming patients were 08_BC (60%,37/62 ), CRF01_AE subtype(21% , 13/62 ) and 07_BC ( 15% ,9/62). Conclusions Partial differences of the point mutations of the HIV-1 strain pol region and frequency of their occurrences exist among Dehong and Kunming patients, HIV-1 strains in Dehong prefecture for the NNRTIs mutations at the T215 Y/N/T, M41L and T69G/N/I/S/A/D are significantly higher than those in Kunming. Six isoforms are found respectively:CRF01_AE, B, C, BC, 08_BC and 07_BC from the epidemic strains of HIV-1 pol region subtype in Dehong and Kunming areas.