Background: In Ghana, programs to expand antiretroviral access are being implemented. In this context, the dynamic genetic evolution of HIV-1 requires continuous surveillance, particularly when diverse genetic forms co-circulate. Methods: Phylogenetic and antiretroviral resistance analyses of HIV-1 partial pol sequences from plasma RNA samples from 207 Ghanaian individuals were performed. Results: 66% of infections were CRF02_AG, whereas 25% were unique recombinant forms (URFs). All 52 URFs were characterized by bootscanning. CRF02_AG was parental strain in 87% of URFs, forming recombinants with genetic forms circulating in minor proportions: CRF06_cpx, sub-subtype A3, CRF09_cpx and subtypes G and D. Two triple recombinants (CRF02_AG/A3/CRF06_cpx and CRF02_AG/A3/CRF09_cpx) were identified. Antiretroviral resistance analyses revealed that six individuals, five of which were antiretroviral drug-experienced, harbored mutations conferring high level of resistance to reverse transcriptase inhibitors. No major resistance mutations were identified in the protease, although insertions of one and three amino acids were detected. Conclusions: The high frequency of URFs detected probably reflects a significant incidence of coinfections or superinfections with diverse viral strains, which increases the genetic complexity of the HIV-1 epidemic in West Africa. Monitoring of HIV-1 drug resistance might provide data on the implications of intersubtype recombination in response to antiretrovirals.

The extraordinary genetic variability of human immunodeficiency virus type 1 (HIV-1) group M has led to the identification of 10 subtypes, 102 circulating recombinant forms (CRFs) and numerous unique recombinant forms. Among CRFs, 11 derived from subtypes B and C have been identified in China, Brazil, and Italy. Here we identify a new HIV-1 CRF_BC in Northern Spain. Originally, a phylogenetic cluster of 15 viruses of subtype C in protease-reverse transcriptase was identified in an HIV-1 molecular surveillance study in Spain, most of them from individuals from the Basque Country and heterosexually transmitted. Analyses of near full-length genome sequences from six viruses from three cities revealed that they were BC recombinant with coincident mosaic structures different from known CRFs. This allowed the definition of a new HIV-1 CRF designated CRF108_BC, whose genome is predominantly of subtype C, with four short subtype B fragments. Phylogenetic analyses with database sequences supported a Brazilian ancestry of the parental subtype C strain. Coalescent Bayesian analyses estimated the most recent common ancestor of CRF108_BC in the city of Vitoria, Basque Country, around 2000. CRF108_BC is the first CRF_BC identified in Spain and the second in Europe, after CRF60_BC, both phylogenetically related to Brazilian subtype C strains.

This study aimed to develop a genotypic method to predict HIV-1 coreceptor usage by employing the nucleotide sequence of the env gene in a tree-augmented naive Bayes (TAN) classifier, and to evaluate its accuracy in prediction compared with other available tools. A wrapper data-mining strategy interleaved with a TAN algorithm was employed to evaluate the predictor value of every single-nucleotide position throughout the HIV-1 env gene. Based on these results, different nucleotide positions were selected to develop a TAN classifier, which was employed to predict the coreceptor tropism of all the full-length env gene sequences with information on coreceptor tropism currently available at the Los Alamos HIV Sequence Database. Employing 26 nucleotide positions in the TAN classifier, an accuracy of 95.6%, a specificity (identification of CCR5-tropic viruses) of 99.4% and a sensitivity (identification of CXCR4/dual-tropic viruses) of 80.5% were achieved for the in silico cross-validation. Compared with the phenotypic determination of coreceptor usage, the TAN algorithm achieved more accurate predictions than WebPSSM and Geno2pheno [coreceptor] (P < 0.05). The use of the methodology presented in this work constitutes a robust strategy to identify genetic patterns throughout the HIV-1 env gene differently present in CCR5-tropic and CXCR4/dual-tropic viruses. Moreover, the TAN classifier can be used as a genotypic tool to predict the coreceptor usage of HIV-1 isolates reaching more accurate predictions than with other widely used genotypic tools. The use of this algorithm could improve the correct prescribing of CCR5 antagonist drugs to HIV-1-infected patients.

Antiretrovirals have been available in Ghana since 2003 for HIV-1 positive pregnant women for prevention of mother-to-child transmission (PMTCT). Suboptimal responses to treatment observed post-PMTCT interventions necessitated the need to investigate the profile of viral mutations generated. This study investigated HIV-1 drug resistance profiles in mothers in selected centres in Ghana on treatment with a history of prophylaxis. Genotypic Drug Resistance Testing for HIV-1 was carried out. Subtyping was done by phylogenetic analysis and Stanford HIV Database programme was used for drug resistance analysis and interpretation. To compare the significance between the different groups and the emergence of drug resistance mutations, p values were used. Participants who had prophylaxis before treatment, those who had treatment without prophylaxis and those yet to initiate PMTCT showed 32% (8), 5% (3) and 15% (4) HIV-1 drug resistance associated mutations respectively. The differences were significant with p value < 0.05. Resistance Associated Mutations (RAMs) were seen in 14 participants (35%) to nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). The most common NRTI mutation found was M184 V; K103 N and A98G were the most common NNRTI mutations seen. Thymidine Analogue Mutations (TAMs) such as M41 L, K70R and T215Y were found in all the groups; the most common of the TAMs found were M41 L and T215Y. Majority of the subtypes were CRF02_AG (82%). In Ghana initiation of uninterrupted treatment upon diagnosis, coupled with drug resistance testing, would produce a better treatment outcome for HIV-1 positive pregnant women.

The analysis of a pol gene fragment encoding protease and part of reverse transcriptase was carried out for 55 sera collected in 2016 and 2018 from HIV-1-infected patients diagnosed in 2014-2018 living in the south of Western Siberia, Russia: Altai Territory (n=11), Republic of Altai (n=15), Kemerovo region (n=18) and Novosibirsk region (n=11). CRF63_02A was the dominant genetic form (>70%) in the Altai Territory and Kemerovo and Novosibirsk regions, with subsubtype A6 comprising <30% of samples. In the Altai Republic, subsubtype A6 was predominant (53%), with 33% of viruses belonging to CRF63_02A. Four CRF63_02A/A6 unique recombinant forms were identified in the Altai Territory, Kemerovo Region, and the Altai Republic. A majority (11 of 15) CRF63_02A viruses from Kemerovo grouped in a cluster. Antiretroviral drug resistance mutations were found in 6 (14%) of 43 drug-naïve patients. This study provides new insights in HIV-1 molecular epidemiology and prevalence of transmitted antiretroviral drug resistance mutations in Southwestern Siberia.