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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Dissection of the Role of Pili and Type 2 and 3 Secretion Systems in Adherence and Biofilm Formation of an Atypical Enteropathogenic Escherichia coli Strain

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Hernandes, Rodrigo T. [1, 2, 3] ; De la Cruz, Miguel A. [3] ; Yamamoto, Denise [2] ; Giron, Jorge A. [3] ; Gomes, Tania A. T. [2]
Total Authors: 5
[1] Univ Estadual Paulista, UNESP, Inst Biociencias, Dept Microbiol & Imunol, Botucatu, SP - Brazil
[2] Univ Fed Sao Paulo UNIFESP, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Sao Paulo - Brazil
[3] Univ Florida, Dept Mol Genet & Microbiol, Emerging Pathogens Inst, Gainesville, FL - USA
Total Affiliations: 3
Document type: Journal article
Source: Infection and Immunity; v. 81, n. 10, p. 3793-3802, OCT 2013.
Web of Science Citations: 19

Atypical enteropathogenic Escherichia coli (aEPEC) strains are diarrheal pathogens that lack bundle-forming pilus production but possess the virulence-associated locus of enterocyte effacement. aEPEC strain 1551-2 produces localized adherence (LA) on HeLa cells; however, its isogenic intimin (eae) mutant produces a diffuse-adherence (DA) pattern. In this study, we aimed to identify the DA-associated adhesin of the 1551-2 eae mutant. Electron microscopy of 1551-2 identified rigid rod-like pili composed of an 18-kDa protein, which was identified as the major pilin subunit of type 1 pilus (T1P) by mass spectrometry analysis. Deletion of fimA in 1551-2 affected biofilm formation but had no effect on adherence properties. Analysis of secreted proteins in supernatants of this strain identified a 150-kDa protein corresponding to SslE, a type 2 secreted protein that was recently reported to be involved in biofilm formation of rabbit and human EPEC strains. However, neither adherence nor biofilm formation was affected in a 1551-2 sslE mutant. We then investigated the role of the EspA filament associated with the type 3 secretion system (T3SS) in DA by generating a double eae espA mutant. This strain was no longer adherent, strongly suggesting that the T3SS translocon is the DA adhesin. In agreement with these results, specific anti-EspA antibodies blocked adherence of the 1551-2 eae mutant. Our data support a role for intimin in LA, for the T3SS translocon in DA, and for T1P in biofilm formation, all of which may act in concert to facilitate host intestinal colonization by aEPEC strains. (AU)

FAPESP's process: 11/12664-5 - Exploring the interactions of Enteropathogenic Escherichia coli with intestinal cells in vitro and in vivo
Grantee:Tânia Aparecida Tardelli Gomes do Amaral
Support type: Regular Research Grants