Streptococcus pyogenes strains in Sao Paulo, Brazil: molecular characterization as a basis for StreptInCor coverage capacity analysis

Autor(es):Mostrar menos -

de Barros, Samar Freschi ^{[1, 2]} ; De Amicis, Karine Marafigo ^{[1, 2]} ; Alencar, Raquel ^{[1, 2]} ; Smeesters, Pierre Robert ^{[3, 4]} ; Trunkel, Ariel ^{[1, 2]} ; Postol, Edilberto ^{[1, 2]} ; Almeida Junior, Joao Nobrega ^[5] ; Rossi, Flavia ^[5] ; Campos Pignatari, Antonio Carlos ^[6] ; Kalil, Jorge ^{[7, 1, 2]} ; Guilherme, Luiza ^{[1, 2, 8]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med, Heart Inst InCor, BR-01246000 Sao Paulo - Brazil

^[2] Natl Inst Sci & Technol, Inst Immunol Invest, BR-01246000 Sao Paulo - Brazil

^[3] Univ Libre Bruxelles, Fac Sci, Inst Biol & Med Mol, Lab Genet & Physiol Bacterienne, B-1050 Brussels - Belgium

^[4] Murdoch Childrens Res Inst, Parkville, Vic 3052 - Australia

^[5] Univ Sao Paulo, Sch Med, Clin Hosp, Microbiol Lab, BR-01246000 Sao Paulo - Brazil

^[6] Univ Fed Sao Paulo, Special Clin Microbiol Lab LEMC, UNIFESP, Sao Paulo - Brazil

^[7] Univ Sao Paulo, Sch Med, Div Clin Immunol & Allergy, BR-01246000 Sao Paulo - Brazil

^[8] Heart Inst HC FMUSP, Clin Hosp, Immunol Lab, BR-05403000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BMC INFECTIOUS DISEASES; v. 15, AUG 5 2015.
• Citações Web of Science: 6

Resumo

Background: Several human diseases are caused by Streptococcus pyogenes, ranging from common infections to autoimmunity. Characterization of the most prevalent strains worldwide is a useful tool for evaluating the coverage capacity of vaccines under development. In this study, a collection of S. pyogenes strains from Sao Paulo, Brazil, was analyzed to describe the diversity of strains and assess the vaccine coverage capacity of StreptInCor. Methods: Molecular epidemiology of S. pyogenes strains was performed by emm-genotyping the 229 isolates from different clinical sites, and PCR was used for superantigen profile analysis. The emm-pattern and tissue tropism for these M types were also predicted and compared based on the emm-cluster classification. Results: The strains were fit into 12 different emm-clusters, revealing a diverse phylogenetic origin and, consequently, different mechanisms of infection and escape of the host immune system. Forty-eight emm-types were distinguished in 229 samples, and the 10 most frequently observed types accounted for 69 % of all isolates, indicating a diverse profile of circulating strains comparable to other countries under development. A similar proportion of E and A-C emm-patterns were observed, whereas pattern D was less frequent, indicating that the strains of this collection primarily had a tissue tropism for the throat. In silico analysis of the coverage capacity of StreptInCor, an M protein-conserved regionally based vaccine candidate developed by our group, had a range of 94.5 % to 59.7 %, with a mean of 71.0 % identity between the vaccine antigen and the predicted amino acid sequence of the emm-types included here. Conclusions: This is the first report of S. pyogenes strain characterization in Sao Paulo, one of the largest cities in the world; thus, the strain panel described here is a representative sample for vaccine coverage capacity analysis. Our results enabled evaluation of StreptInCor candidate vaccine coverage capacity against diverse M-types, indicating that the vaccine candidate likely would induce protection against the diverse strains worldwide. (AU)

• Processo FAPESP: 07/59262-3 - Identificacao das cepas de streptococcus pyogenes isolados na cidade de sao paulo, atraves de genotipagem.
• Beneficiário: Luiza Guglielmi
• Modalidade de apoio: Auxílio à Pesquisa - Regular