A specific subtype C of human immunodeficiency virus type 1 circulates in Brazil

• Autor(a) principal: Soares, M. A.
• Data de Publicação: 2003
• Outros Autores: Oliveira, T. de, Brindeiro, R. M., Diaz, Ricardo Sobhie [UNIFESP], Sabino, E. C., Brigido, L., Pires, I. L., Morgado, M. G., Dantas, M. C., Barreira, D., Teixeira, P. R., Cassol, S., Tanuri, A., Brazilian Network Drug Reistance S
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1097/01.aids.0000042595.93174.a4; http://repositorio.unifesp.br/handle/11600/27117
• topic: subtype C; drug resistance mutations; subtype polymorphism; HIV in primary infection; signature sequence

Objective: To characterize the subtype C strains of HIV type I that circulate in Brazil, especially those originated from the southern part of the country.Design and methods: One hundred and twelve HIV-1-positive subjects had their plasma viral RNA extracted. Protease (PR) and reverse transcriptase (RT) genomic regions were polymerase chain reaction-amplified and sequenced for subtype determination. Subtype C strains were selected and compared to other strains of this subtype from the database, and specific amino acid signature patterns were searched.Results: Brazilian subtype C viruses form a very strong monophyletic group when compared to subtype C viruses from other countries and presented specific signature amino acids. Recombinants between subtype C and B viruses have been documented in areas of co-circulation. the incidence of primary PR and RT inhibitor resistance mutations in drug-naive subjects was observed. An increasing number of secondary resistance mutations was also seen, some of which are characteristic of subtype C-related sequences.Conclusions: Introduction of subtype C of HIV-1 in Brazil was likely a single event of one or a mixture of similarly related strains. Recombination between subtype C and B viruses is an ongoing process in the country. Primary and secondary drug resistance mutations were observed, although some of the secondary mutations could be associated with subtype C molecular signatures. Subtype-specific polymorphisms of PR and RT sequences found in this subtype C Brazilian variant might influence this emergence and have an impact on HIV treatment and on vaccine development in the country. (C) 2003 Lippincott Williams Wilkins.