Increased Frequency of A581G Mutation in Isolates from Gabonese HIV-Infected Individuals.

Background: Studying malaria parasites cross resistance to sulfadoxine-pyrimethamine (SP) and trimethoprim-sulfamethoxazole (cotrimoxazole, CTX) is necessary in areas coendemic for malaria and HIV. Polymorphism and frequency of drug resistance molecular markers, and genes have been assessed in isolates from HIV-infected adults, in Gabon.

Materiel And Methods: A cross-sectional study was conducted in three HIV care and treatment centers, at Libreville, the capital city of Gabon and at Oyem and Koulamoutou, two rural cities between March 2015 and June 2016. -infected HIV adults were selected. Analysis of and genes was performed using high resolution melting (HRM) technique.

Results: A581G mutation was found in 23.5% (8/34) of the isolates. Triple mutation (51I-59R-108N) was predominant (29.4%; n=10) while 17.6% (n=6) of the isolates carried a quadruple mutation 51I-59R-108N + 437G; 51I-108N + 437G-581G; 51I-59R-108N + 581G). Highly resistant genotype was detected in around 10% (n=3) of the isolates. The quintuple mutation (triple 51I-59R-108N and double 437-581) was only found in isolates from two patients who did not use CTX. The most frequent haplotypes were those with a single mutation (CNIAKA) (36%) and a quadruple mutation (CIK, IKA, and IAK). Mixed unknown genotypes were found at codon 164 in three isolates. Mixed genotypes were more frequent at codons 51 (23.5%; n=8) and 59 (20.5%; n=7) (<0.01).

Conclusion: A581G mutation as well as new combination of quintuple mutations is found for the first time in isolates from HIV-infected patients in Gabon in comparison to a previous study. The detection of these genotypes at a nonnegligible frequency underlines the need of a regular surveillance of antifolates drug resistance.