Study of HIV Resistance Mutations Against Antiretrovirals using Bioinformatics Tools.

BACKGROUND: Antiretroviral drugs to HIV-1 (ARV) are divided into classes: Nucleotide Reverse Transcriptase Inhibitors (NRTIs); Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs); Protease Inhibitors (PIs); Integrase Inhibitors (INIs); fusion inhibitors and entry Inhibitors. The occurrence of mutations developing resistance to antiretroviral drugs used in HIV treatment take place in a considerable proportion and has accumulated over its long period of therapy. OBJECTIVE: This study aimed to identify resistance mutations to antiretrovirals used in the treatment of HIV-1 in strains isolated from Brazilian territory deposited at Genbank, as well as to relate to the clinical significance and mechanism of action. METHODS: Elucidation of these mutations was by comparative method of peptide sequence resulting from genes encoding therapeutic targets in HIV antiretroviral therapy (ART) of the strains with a reference sequence through bioinformatic genetic information manipulation techniques. RESULTS: Of the 399 sequences analyzed, 121 (30.3%) had some type of mutations associated with resistance to some class of antiretroviral drug. Resistance to NNRTIs was the most prevalent, detected in 77 (63.6%) of the 121 mutated sequences, compared to NRTIs and PIs, whose resistance was detected in 60 (49.6%) and 21 (17.3%), respectively, and to INIs, only 1 (0.8%) sample showed associated resistance mutation. CONCLUSION: Resistance to HIV ARV was detected at a considerable rate of 30.3%, showing some concerns about the percentage of viral strains that escape the established therapeutic regimen and that circulate currently in Brazil. The non-use of NNRTIs in Brazil is justified by the emergence of resistance mutations. The low prevalence of mutations against INIs is because drugs in this class have a high genetic barrier.

Characterization of the Genotypic Profile of Hepatitis Delta Virus: Isolation of HDV Genotype-1 in the Western Amazon Region of Brazil.

UNLABELLED: The hepatitis delta virus (HDV) is a hepatotropic subvirus that is dependent on the hepatitis B virus (HBV) and supplies the viral envelope containing the surface antigen of hepatitis B. Viral genetic diversity is related to the geographical origin of the isolates, and there are at least eight genotypes that are referred to as HDV-1 through HDV-8. HDV-3 is responsible for epidemics of severe and fulminant hepatitis, which are common in northeastern South America. HDV-3 is prevalent in the Brazilian Amazon and is associated with the increased aggressiveness of HDV infections. Although isolated, the characteristics of the clinical presentation of HDV-1 in the Amazon region have not yet been clearly reported. OBJECTIVE: This study aims to assess the genotypic and clinical characteristics of individuals with the HDV-1 genotype in the western Amazon region. METHODS: The HDV was genotyped by nested PCR-RFLP and sequencing from serum samples of 56 patients with HBV/HDV infection. The genotypes were correlated with the clinical characteristics presented by patients with HBV/HDV infection. RESULTS: A prevalence of 92.3% for the HDV-3 genotype (n = 48) and 7.6% (n = 4) for the HDV-1 genotype was observed. CONCLUSION: To date, this is the most extensive clinical study of HDV-1 genotype infections in the nonindigenous population of Western Amazonia.