1. A specific subtype C of human immunodeficiency virus type 1 circulates in Brazil.
- Author
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Soares MA, De Oliveira T, Brindeiro RM, Diaz RS, Sabino EC, Brigido L, Pires IL, Morgado MG, Dantas MC, Barreira D, Teixeira PR, Cassol S, and Tanuri A
- Subjects
- Adolescent, Adult, Africa, Amino Acid Sequence, Brazil epidemiology, Drug Resistance, Viral genetics, Female, Genetic Variation, HIV Infections epidemiology, HIV Protease genetics, HIV Reverse Transcriptase genetics, HIV-1 genetics, HIV-1 isolation & purification, Humans, India, Male, Middle Aged, Molecular Sequence Data, Mutation, Phylogeny, Polymerase Chain Reaction methods, RNA, Viral isolation & purification, Virology methods, HIV Infections virology, HIV-1 classification
- Abstract
Objective: To characterize the subtype C strains of HIV type 1 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-naïve 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.
- Published
- 2003
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