Enterotoxigenic Escherichia coli EtpA mediates adhesion between flagella and host cells

Koushik Roy et al. Nature 457, 594-598 (29 January 2009)

Speaker: Po-Pin Hung (洪伯斌)               Time: 14:00~15:00, June. 10, 2009

Commentator: Lien-I Hor (何漣漪老師)   Place: Room 601

Abstract：

Adhesion to epithelial cells is the first step for most bacteria to establish the colonization, and subsequently infection in the specific host cells. The fimbrial bacterial adhesions are well-known mediators in this step for almost bacteria. The breakthrough finding about the adherence-associated function, other than the organelle of locomotion, of flagella in enteropathogenic Escherichia coli (EPEC) has been reported in 2002. The authors further illustrate the adherence function of the flagella in enterotoxigenic E. coli (ETEC).

Since the ETEC is a major cause of diarrhoea in travellers and children in developing countries, the strategy for pubic healthy focus on the vaccination development. This process ceased in the problem of diversity of antigen variation of the flagellar (H) antigens.

In addition, this study demonstrates that EtpA, a TPS exoprotein adhesin of enterotoxigenic E. coli, mimics and interacts with highly conserved regions of flagellin, the major subunit of flagella, and that these interactions are critical for adherence and intestinal colonization in the several and different H serotypes of E. coli. The EtpA-like molecules encoded by other motile pathogens suggests a potential common pattern for bacterial adhesion, whereas participation of conserved regions of flagellin in adherence and then colonization may be the dawn for development of vaccines for gram-negative bacteria.

References：

1.   Torres, A. G., Zhou, X. & Kaper, J. B. Adherence of diarrheagenic Escherichia coli strains to epithelial cells. Infect. Immun. 73, 18–29 (2005).

2.    Dorsey, F. C., Fischer, J. F. & Fleckenstein, J. M. Directed delivery of heat-labile enterotoxin by enterotoxigenic Escherichia coli. Cell. Microbiol. 8, 1516–1527 (2006).