Analysis of the Virulence of an Atypical Enteropathogenic Escherichia coli Strain In Vitro and In Vivo and the Influence of Type Three Secretion System

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Sampaio, Suely C. F. ; Moreira, Fabiana C. ; Liberatore, Ana M. A. ; Vieira, Monica A. M. ; Knobl, Terezinha ; Romao, Fabiano T. ; Hernandes, Rodrigo T. ; Ferreira, Claudete S. A. ; Ferreira, Antonio P. ; Felipe-Silva, Aloisio ; Sinigaglia-Coimbra, Rita ; Koh, Ivan H. J. ; Gomes, Tania A. T.

• Tipo de documento: Artigo Científico
• Fonte: BIOMED RESEARCH INTERNATIONAL; v. 2014, p. 9-pg., 2014-01-01.

Resumo

Atypical enteropathogenic Escherichia coli (aEPEC) inject various effectors into intestinal cells through a type three secretion system (T3SS), causing attaching and effacing (A/E) lesions. We investigated the role of T3SS in the ability of the aEPEC 1711-4 strain to interact with enterocytes in vitro (Caco-2 cells) and in vivo (rabbit ileal loops) and to translocate the rat intestinal mucosa in vivo. A T3SS isogenic mutant strain was constructed, which showed marked reduction in the ability to associate and invade but not to persist inside Caco-2 cells. After rabbit infection, only aEPEC 1711-4 was detected inside enterocytes at 8 and 24 hours pointing to a T3SS-dependent invasive potential in vivo. In contrast to aEPEC 1711-4, the T3SS-deficient strain no longer produced A/E lesions or induced macrophage infiltration. We also demonstrated that the ability of aEPEC 1711-4 to translocate through mesenteric lymph nodes to spleen and liver in a rat model depends on a functional T3SS, since a decreased number of T3SS mutant bacteria were recovered from extraintestinal sites. These findings indicate that the full virulence potential of aEPEC 1711-4 depends on a functional T3SS, which contributes to efficient adhesion/invasion in vitro and in vivo and to bacterial translocation to extraintestinal sites. (AU)

• Processo FAPESP: 08/53812-4 - Invasão: um mecanismo potencial de virulência em Escherichia coli enteropatogênica atípica?
• Beneficiário: Tânia Aparecida Tardelli Gomes do Amaral
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/12664-5 - Explorando as interações de Escherichia coli enteropatogênica com células intestinais in vitro e in vivo
• Beneficiário: Tânia Aparecida Tardelli Gomes do Amaral
• Modalidade de apoio: Auxílio à Pesquisa - Regular