Fimbrial Adhesins Produced by Atypical Enteropathogenic Escherichia coli Strains

Autor(es)

Hernandes, Rodrigo T. ^{[1, 2]} ; Velsko, Irina ^[2] ; Sampaio, Suely C. F. ^[1] ; Elias, Waldir P. ^[3] ; Robins-Browne, Roy M. ^{[4, 5]} ; Gomes, Tania A. T. ^[1] ; Giron, Jorge A. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Sao Paulo - Brazil

^[2] Univ Florida, Dept Mol Genet & Microbiol, Emerging Pathol Inst, Gainesville, FL 32610 - USA

^[3] Inst Butantan, Bacteriol Lab, Sao Paulo - Brazil

^[4] Univ Melbourne, Dept Microbiol & Immunol, Melbourne, Vic 3010 - Australia

^[5] Royal Childrens Hosp, Murdoch Children Res Inst, Melbourne, Vic 3010 - Australia

• Tipo de documento: Artigo Científico
• Fonte: Applied and Environmental Microbiology; v. 77, n. 23, p. 8391-8399, DEC 2011.
• Citações Web of Science: 30

Resumo

Atypical enteropathogenic Escherichia coli (aEPEC) has emerged as a significant cause of pediatric diarrhea worldwide; however, information regarding its adherence mechanisms to the human gut mucosa is lacking. In this study, we investigated the prevalence of several (fimA, ecpA, csgA, elfA, and hcpA) fimbrial genes in 71 aEPEC strains isolated from children with diarrhea (54 strains) and healthy individuals (17 strains) in Brazil and Australia by PCR. These genes are associated with adhesion and/or biofilm formation of pathogenic and commensal E. coli. Here, the most prevalent fimbrial genes found, in descending order, were hcpA (98.6%), ecpA (86%), fimA (76%), elfA (72%), and csgA (19.7%). Phenotypic expression of pili in aEPEC strains was assessed by several approaches. We were not able to detect the hemorrhagic coli pilus (HCP) or the E. coli laminin-binding fimbriae (ELF) in these strains by using immunofluorescence. Type 1 pili and curli were detected in 59% (by yeast agglutination) and 2.8% (by Congo red binding and immunofluorescence) of the strains, respectively. The E. coli common pilus (ECP) was evidenced in 36.6% of the strains on bacteria adhering to HeLa cells by immunofluorescence, suggesting that ECP could play an important role in cell adherence for some aEPEC strains. This study highlights the complex nature of the adherence mechanisms of aEPEC strains involving the coordinated function of fimbrial (e.g., ECP) and nonfimbrial (e.g., intimin) adhesins and indicates that these strains bear several pilus operons that could potentially be expressed in different niches favoring colonization and survival in and outside the host. (AU)

• Processo FAPESP: 06/54359-6 - Identificação e caracterização da estrutura responsável pelo padrão de adesão difusa em uma amostra de Escherichia coli enteropatogênica (EPEC) atípica mutada em intimina
• Beneficiário: Rodrigo Tavanelli Hernandes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado