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Abstract
Identification of a specific subtype C human immunodeficiency virus type 1 in Brazil: implications on highly active antiretroviral treatment
M A Soares1, T Oliveira2, R M Brindeiro3, R S Diaz4, E C Sabino4, L Brigido5, I L Pires6, M G Morgado7, M C Dantas8, P R Teixeira8, S Cassol2, A Tanuri1
1Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 2University of Natal, Durban, South Africa; 3Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; 4Universidade Federal de Sao Paulo, Sao Paulo, Brazil; 5Instituto Adolfo Lutz, Sao Paulo, Brazil; 6Instituto de Biologia do Exercito, Rio de Janeiro, Brazil; 7Fundacao Instituto Oswaldo Cruz, Rio de Janeiro, Brazil; 8Ministerio da Saude, Brasilia, Brazil
Background. Subtype C of HIV-1 is currently responsible for over 50% of the infections worldwide, and it is in clear expansion in Africa and India. Brazil also seems to experience a visible increase of this subtype, notoriously in the southernmost part of the country, where we find frequencies as high as 35%. We wanted to further analyze the strains of HIV-1 subtype C that circulate in the country.
Methods. One hundred thirteen HIV-1-positive subjects had their plasma viral RNA extracted. Protease (PR) and reverse transcriptase (RT) genomic regions were PCR-amplified and sequenced for subtype and drug resistance pattern determination. Subtype C strains were compared to other strains of this subtype from the database, and specific amino acid signature patterns were searched.
Results. Brazilian viruses form a very strong monophyletic group when compared to subtype C viruses from other countries. They presented specific signature amino acids, as evidenced by VESPA analysis. Recombinant viruses between subtype C and B viruses have been documented in areas of co-circulation. Finally, the incidence of primary PR and RT inhibitor resistance mutations in drug-naive subjects was observed for the first time. An increasing number of secondary resistance mutations was also seen, some of which are characteristic of subtype C-related sequences.
Conclusions. Subtype C of HIV-1 seems to be expanding both quantitatively and geographically in Brazil, notoriously in the south-southeast. Introduction of this subtype in the country 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 Brazil. Finally, the emergence of primary and secondary drug resistance mutations seems to be increasing in the country. Subtype-specific polymorphisms of PR and RT sequences might influence this emergence and have an impact on HIV treatment and on vaccine development in Brazil.
The XIV International AIDS Conference
Abstract no.
TuPeC4787
Suggested Citation
" M A Soares , , et al.
Identification of a specific subtype C human immunodeficiency virus type 1 in Brazil: implications on highly active antiretroviral treatment
.
Poster Exhibition:
The XIV International AIDS Conference:
Abstract no.
TuPeC4787"
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