12th International AIDS Conference Geneva, Switzerland - June 28-July 3, 1998

Int Conf AIDS 1998 Jun 28-Jul 3; 12:22 (abstract no. 11198)

Soler Claudin C, Carmen J, Rosales G
Unidad de Investigacion En Retrovirus Fac. Quimica Unam/Indre SSA, Tomas, Mexico.

OBJECTIVES: To compare the results of genetic subtyping of HIV by the env heteroduplex mobility assay (envHMA) and by gagPCR-FLP.

METHODS: DNA isolated from HIV-infected individuals PBMC's was used to amplify the gag and env regions. For envHMA, the Heteroduplex, Mobility Analysis version 2 kit, donated by the NIH Reference Reagent Program was used. For gag, two sets of primers were designed within conserved regions that amplify a 732 bp segment (positions 815-1547 from the HIV BRU strain). The amplicons were analyzed by agarose gel separation after digestion with restriction enzymes selected by computer analysis of HIV-1 reported sequences (Los Alamos Human Retroviruses Database, 1995).

RESULTS: Up to now, 236 DNA samples have been tested by envPCR, (all PCR positive for the human beta-globin gene amplification), but only 59 yield env amplicons (25%). Eleven of these were typed by HMA and shown to be B subtype. Two samples gave hetroduplex bands of similar Rf with the B prototypes and the C1 reference strains. Eighty eight samples have been tested by gagPCR, and 55 gave positive results (62%). Digestion of gag amplicons with DdeI in 41 samples gave the common pattern of bands expected for the B subtype (bands of 125, 140 and 370 bp). The other 14 samples lack the 370 bp fragment but have bands between 500-700 bp in size, which are found within B, D and G subtype sequences.

CONCLUSION: In our study, a low percentage of samples were envPCR positive. This could be due to problems with inhibitors in our PCR procedure, but we cannot discard poor annealing of primers due to differences in sequence within our DNA's. Although we found gagRFLP patterns of B subtype strains in most of our samples, other gag genotypes may be present in our population.

Copyright © 1998 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.