Natural polymorphism of HIV-1 subtype G protease and cleavage sites

Transmitted drug resistance in nonsubtype B HIV-1 infection

HIV-1 nonsubtype B variants account for the majority of HIV infections worldwide. Drug resistance in individuals who have never undergone antiretroviral therapy can lead to early failure and limited treatment options and, therefore, is an important concern. Evaluation of reported transmitted drug resistance (TDR) is challenging owing to varying definitions and study designs, and is further complicated by HIV-1 subtype diversity. In this article, we discuss the importance of various mutation lists for TDR definition, summarize TDR in nonsubtype B HIV-1 and highlight TDR reporting and interpreting challenges in the context of HIV-1 diversity. When examined carefully, TDR in HIV-1 non-B protease and reverse transcriptase is still relatively low in most regions. Whether it will increase with time and therapy access, as observed in subtype-B-predominant regions, remains to be determined.

Genomic characterization of a novel HIV type 1 B/G intersubtype recombinant strain from an injecting drug user in Germany

Recombinant forms of HIV-1 contribute significantly to the ongoing epidemic. In the present study we characterize the full-length genome of a novel B/G intersubtype recombinant strain from a patient with a history of injection drug use. This is the first evidence of a B/G recombinant among injecting drug users in Germany. Moreover, this genetically divergent strain has important clinical implications since it was undetectable in the NucliSens HIV-1 QT assay and significantly underquantified by the COBAS MONITOR version 1.5 test relative to the LCx HIV RNA Quantitative assay. Phylogenetic analysis revealed that this recombinant virus is ancestrally related to CRF14_BG, but carries two additional subtype B-derived segments within vif and pol integrase.