| Abstract: | Typical human immunodeficiency virus-1 subtype B (HIV-1B) sequences present a
GPGR signature at the tip of the variable region 3 (V3) loop; however, unusual
motifs harbouring a GWGR signature have also been isolated. Although
epidemiological studies have detected this variant in approximately 17-50% of
the total infections in Brazil, the prevalence of B"-GWGR in the southernmost
region of Brazil is not yet clear. This study aimed to investigate the C2-V3
molecular diversity of the HIV-1B epidemic in southernmost Brazil. HIV-1
seropositive patients were ana-lysed at two distinct time points in the state of
Rio Grande do Sul (RS98 and RS08) and at one time point in the state of Santa
Catarina (SC08). Phylogenetic analysis classified 46 individuals in the RS98
group as HIV-1B and their molecular signatures were as follows: 26% B"-GWGR, 54%
B-GPGR and 20% other motifs. In the RS08 group, HIV-1B was present in 32
samples: 22% B"-GWGR, 59% B-GPGR and 19% other motifs. In the SC08 group, 32
HIV-1B samples were found: 28% B"-GWGR, 59% B-GPGR and 13% other motifs. No
association could be established between the HIV-1B V3 signatures and exposure
categories in the HIV-1B epidemic in RS. However, B-GPGR seemed to be related to
heterosexual individuals in the SC08 group. Our results suggest that the
established B"-GWGR epidemics in both cities have similar patterns, which is
likely due to their geographical proximity and cultural relationship. |
