Analyses of HIV-1 integrase gene sequences among treatment-naive patients in the Eastern Cape, South Africa.

Drug resistance has been recognized in all available therapeutic class of medications for the management of human immunodeficiency virus-1 (HIV-1) infected patients. This makes the continuous study of HIV drug resistance and new treatment options pertinent to patients and researchers globally. The aim of this study is to analyze the complete HIV-1 integrase gene for the possible occurrence of resistance mutations or polymorphisms. We performed genetic analyses on 48 treatment-naive HIV-1-infected patients using nested polymerase chain reaction. Integrase drug-related resistance mutation (DRMs) analysis was performed on all generated sequences according to Stanford HIV drug interpretation program and the International AIDS Society-USA guidelines while phylogenetic analysis was inferred using MEGA 6. The study revealed no major resistance-associated mutation. However, E157Q (2.1%), L74M/I (4.2%), and P142T (2.1%) were the observed accessory and polymorphic mutations. Naturally occurring polymorphism observed were E11D, K14R, D25E, V31I, M50I, V72I, P90T, F100Y, L101I, T124A, T125A, K136Q, D167E, V201I, L234I, A265V, A269K, D278A, and S283G. Phylogenetic analysis delineated all the sequences as HIV-1 subtype C. The study revealed the absence of major integrase inhibitors associated resistance mutations in a setting where integrase inhibitor is administered as salvage therapy in patients developing resistance to first and second-line antiretroviral treatment. However minor and natural polymorphisms were observed and thus may influence the outcome of each treatment regimen. However, additional studies are required to precisely evaluate the impact of these mutations on integrase inhibitors in the Eastern Cape of South Africa.

Molecular Genetics and the Incidence of Transmitted Drug Resistance Among Pre-Treatment HIV-1 Infected Patients in the Eastern Cape, South Africa.

BACKGROUND: Transmitted drug resistance (TDR) remains a significant threat to Human immunodeficiency virus (HIV) infected patients that are not exposed to antiretroviral treatment. Although, combined antiretroviral therapy (cART) has reduced deaths among infected individuals, emergence of drug resistance is gradually on rise. OBJECTIVE: To determine the drug resistance mutations and subtypes of HIV-1 among pre-treatment patients in the Eastern Cape of South Africa. METHODS: Viral RNA was extracted from blood samples of 70 pre-treatment HIV-1 patients while partial pol gene fragment amplification was achieved with specific primers by RT-PCR followed by nested PCR and positive amplicons were sequenced utilizing ABI Prism 316 genetic sequencer. Drug resistance mutations (DRMs) analysis was performed by submitting the generated sequences to Stanford HIV drug resistance database. RESULTS: Viral DNA was successful for 66 (94.3%) samples of which 52 edited sequences were obtained from the protease and 44 reverse transcriptase sequences were also fully edited. Four major protease inhibitor (PI) related mutations (I54V, V82A/L, L76V and L90M) were observed in seven patients while several other minor and accessory PIs were also identified. A total of 11(25.0%) patients had NRTIs related mutations while NNRTIs were observed among 14(31.8%) patients. K103N/S, V106M and M184V were the most common mutations identified among the viral sequences. Phylogenetic analysis of the partial pol gene indicated all sequences clustered with subtype C. CONCLUSION: This study indicates that HIV-1 subtype C still predominates and responsible for driving the epidemic in the Eastern Cape of South Africa with slow rise in the occurrence of transmitted drug resistance.