[Development of a rapid subtype-screening assay for the env region of HIV-1 CRF strains in Guangxi.].
BACKGROUND
To develop a simple and rapid subtype-screening assay for the env region of the circulating recombinant form (CRF) of human immunodeficiency virus type 1 (HIV-1) in Guangxi.


METHODS
Proviral DNA from HIV-1 positive samples were extracted and subjected to the first round PCR with universal primers for the env region that can detect HIV-1 M group isolates. In the second round PCR, two pairs of subtype-specific primers that were designed to detect subtype C or B'/C and CRF01-AE respectively were added into one tube. The PCR products of different subtypes could be distinguished in agarose-gel electrophoresis. Additionally, all of these samples were sequenced and analyzed phylogenetically.


RESULTS
Phylogenetic analysis of the env region of 50 samples showed that 3 samples (6%) were infected with CRF08-BC, 43 (86%) with CRF01-AE, and 4 (8%) remained unclassifiable. Detection of the subtype-specific primer sets revealed that 3 were subtype C or B'/C (100%), 39 were CRF01-AE (90.7%), with an adequate sensitivity (91.3%) and a high specificity (100%). Non-specific bands occasionally appeared but did not interfere with interpretation of the results. The phylogenetic analysis was consistent with subtype-specific primer sets and the consistency rate was 92%. The average reproducibility was 100% for CRF08-BC samples and 93.8% for CRF01-AE samples.


CONCLUSIONS
A simple, rapid and low cost assay was developed for subtype-screening of CRF01-AE in Guangxi.
Liang
H
H
Guangxi Medical University, Nanning 530021, China.
Luo
H
H
Shao
Y M
YM
Liu
W
W
Zhang
Z Y
ZY
Xing
H
H
Lu
C J
CJ
Shen
J
J
Mai
Z D
ZD
D002681:China; D015658:HIV Infections / Q000821:virology; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D010802:Phylogeny; D015203:Reproducibility of Results