HIV type 1 genetic variability in the northern part of Cameroon

In 1995, 53 blood samples from Muslim patients with AIDS, or who were thoug ht to have AIDS, were collected in the main hospitals of Adamaoua Province, in the northern part of Cameroon, The variable env C2V3 region of HIV-1 wa s amplified by nested PCR and phylogenetically analyzed. The results indica ted that of 15 amplified samples, 1 belonged to HIV-1 group O, 1 to HIV-1 s ubtype D, 1 to subtype G, 2 to subtype H, and 10 to subtype A. Furthermore, the northern Cameroonian subtype A could be divided into at least two subc lusters as shown by the env tree as well as by two remarkably conserved hex americ amino acid sequences in the apex of V3 (GPGQAF in one subcluster and GPGQTF in the other). This distinction suggests that the HIV-1 subtype A c irculating in northern Cameroon evolved from two main sources. More recentl y, three HIV-1 strains from Nigeria (IBNG) and Djibouti (DJ263 and DJ264), previously reported on the basis of their env C2V3 sequences as subtype A, were found to have a similar A/G mosaic structure alongside their full-leng th sequence and were tentatively designated as members of a new subtype cal led "IBNG," Interestingly, within the northern Cameroonian subtype A descri bed, the isolates of the second subcluster clustered distinctly with these A/G mosaic strains, strongly suggesting that they may be members of the IBN G subtype.