Prevalence of naturally occurring NS5A resistance-associated substitutions in patients infected with hepatitis C virus subtype 1a, 1b, and 3a, co-infected or not with HIV in Brazil.

Background: Non-structural 5A protein (NS5A) resistance-associated substitutions (RASs) have been identified in patients infected with hepatitis C virus (HCV), even prior to exposure to direct-acting antiviral agents (DAAs). Selection for these variants occurs rapidly during treatment and, in some cases, leads to antiviral treatment failure. DAAs are currently the standard of care for hepatitis C treatment in many parts of the world.

HCV inter-subtype 1a/1b recombinant detected by complete-genome next-generation sequencing.

Next-generation sequencing (NGS) provides a practical approach to HCV complete-genome sequencing, detecting low-frequency variants and allowing analysis of viral genetic diversity (quasispecies) in the sample, and so far, it is very useful for identifying preexisting drug-resistant mutants and emerging escape mutations, as well as detecting viral recombinants containing genomic regions from different genotypes and subtypes. The aim of this study was to analyze the complete coding region of hepatitis C virus (HCV) genotype 1 (subtypes 1a and 1b) from patients with chronic infection who were direct-acting antiviral (DAA) naïve. Next-generation sequencing (Ion Torrent™ PGM) was used to determine the sequence of the complete coding region of 100 HCV-monoinfected DAA-naïve patients (51 and 49 subtypes 1a and 1b, respectively).

Genetic diversity and primary resistance among HIV-1-positive patients from Maringá, Paraná, Brazil.

The objective of this study is to identify subtypes of Human Immunodeficiency Virus type 1 (HIV-1) and to analyze the presence of mutations associated to antiretroviral resistance in the protease (PR) and reverse transcriptase (RT) regions from 48 HIV-1 positive treatment naïve patients from an outpatient clinic in Maringá, Paraná, Brazil. Sequencing was conducted using PR, partial RT and group-specific antigen gene (gag) nested PCR products from retrotranscribed RNA. Transmitted resistance was determined according to the Surveillance Drug Resistance Mutation List (SDRM) algorithm.