Identification Of Novel HIV-1 Recombinant Subtypes Among Cross-border Travelers In Yunnan Province And Its Drug Resistance Mutation For Research

Acuired Immundeficiency Syndrom(AIDS)is caused by HIV-1 infection with characterization of human body immundeficiency.It has become one of the global epidemics threating public health seriously.Yunnan Province is the earliest region of HIV-1 endemic in China and also the orgin area of HIV-1 spreading to other province of China.Yunnan Province is located in the southwest border of China.There are 8 prefactures and 25 counties in this province,bordering Southeast Asian countris including Myanmar,Laos and Vietnam.The length of border line is 4,060 kilometers,accounting for 1/6 of whole land border line of China.The border areas are connected with neighboring countries.There,the residenting people have similar living habits with that neighboring countris.The marriage and mutual markets are very common.The economic and trade exchanges are frequent and there is no natural barrier to disease transmission.Particularly,the major drug product region,Golden Triangle,is located in this area.In current study,the entering travelers with HIV-1 infction were recruited at entry-exit land ports of Yunnan province.The distribution of HIV-1 subtypes was investigated,and novel recombination or subtypes were determined.Further,the drug resistant mutation of HIV-1 pol gene for no accept HAART therapy was detected to clarify the prevalence of drug-resistant HIV-1 strains in this population.Firstly,between 2003 and 2012,more than 2,000 entering travelers at land ports of Yunnan Province were dected to have HIV-1 infection.The extracted RNA from plasma was submitted to have gag-pol gene amplification and sequence determination.As a result,the genotypes of 60 samples couldn’t be classified by analysis on partial sequence.The amplification and sequencing of full length genome is necessary.Since the length of HIV-1 genome is about 9.7 kb,amplification was performed on overlapped six fragments,consisted of gag-pol(2.6 kb),pol(3.1 kb),vif(1.5 kb),env1(1.95 kb),env2(1.75 kb)and end(1 kb).Of the 60 samples having genome amplification,full-length sequences were obtained from 26 samples with amplification efficiency of 43%.The genotypes of these 26 samples were analyzed using MEGA 7.0 software.Among,4 samples have been clustered together with known HIV-1 subtype or recombinants.Accordingly,sample 07091 could be determined as subtypes C,sample 09093 as subtype 86_BC,sample 09102 as subtype 62_BC and sample 08237 as subtype 08_BC.The remained 22 cases couldn’t clustered as known HIV-1 clade.Further analysis using simplot software showed that there were various unique recombination forms(URFs)patterns including 8 cases of BC,7 cases of 01 C,4 cases of 01 B and 3 cases of CPX,were circulating in this population.Each recombination patterns was consisted of more than 2 types of reconbinants.Secondly,the HIV-1 pol fragment(Prot and RT region)from 498 cross-border populations from 2003 to 2012 was amplified and sequenced.249 sequences were successfully obtained and submitted to the Stanford HIV Drug Resistance Database for HAART resistant mutation analysis.From all the detected sampls,a total of 32 drug resistant mutations from 249 enteing travelers from Myanmar were identified,accounting for case rate with drug resistance of 12.8%.Of 32 identified drug resistant mutations,6 were found in PR and 29 in RT.As the floating population may takne as bridge for HIV/AIDS epidemic,cross-border travelers have played a vital role in promoting the spread of HIV-1 and other infectious pathogens.Regarding to the high prevalence of drug resistence among this population,it is necessary to monitor on the carring of transmitted drug resistant HIV-1 strins.The findings on HIV-1 molecular epidemic in cross-border population of Yunnan Province during 2003-2012 have showed that the HIV-1 infection rate is high,the distribution of genetic subtypes are complex,and there are a large number of unknown genes and possibly new recombinant genotypes in this population.It is urgent to analyze the full-length genomes of these samples to determine whether they are new gene subtypes or clarify new recombination patterns to further elucidate the genomic characteristics of possible new viruses.In addition,the occurrence rate of TDR in this population is higher than that of other documeted population.It is expected that the obtained results is very important for HIV-1 transmission monitoring,clinical treatment and vaccine development.