Phylogenetic Analysis of Ethiopian HIV-1 Subtype C Near Full-Length Genomes Reveals High Intrasubtype Diversity and a Strong Geographical Cluster

Abstract

In this study, we characterize HIV-1 subtype C (HIV-1C) strains at the near full-length genome (NFLG) level and perform genotypic drug resistance testing (GRT) and genotypic tropism testing (GTT) from Ethiopia (HIV-1CET). Plasma samples (n = 150) were obtained from therapy-naive individuals residing in Addis Ababa, Ethiopia in 2008. HIV-NFLG was performed in a subset of patients (n = 30). GRT (pol) and GTT (V3 env) were performed using in-house methods. GTT was analyzed by PhenoSeq-C. The phylogenetic analysis of the NLFG identified two separate clusters of HIV-1CET, although all strains formed one large overarching cluster together. At NFLG, greater diversity was found among HIV-1CET strains compared to HIV-1C strains from other geographical locations. The geographic clustering was weak in the small subgenomic (pol and env) regions. The primary drug-resistant mutations were identified at a low level (<5%). GTT identified that 12% (12/102) of the patients were predicted to be harboring X4-tropic or both R5/X4-tropic viruses.