Open AccessSurface‐layer protein extracts from Lactobacillus helveticus inhibit enterohaemorrhagic Escherichia coli O157:H7 adhesion to epithelial cells
Author(s) -
JohnsonHenry Kathene C.,
Hagen Karen E.,
Gordonpour Mahsa,
Tompkins Thomas A.,
Sherman Philip M.
Publication year - 2007
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2006.00791.x
Subject(s) - microbiology and biotechnology , biology , escherichia coli , s layer , pathogen , probiotic , bacteria , in vitro , adhesion , biochemistry , chemistry , genetics , organic chemistry , gene
Summary Adherence of intestinal pathogens, including Escherichia coli O157:H7, to human intestinal epithelial cells is a key step in pathogenesis. Probiotic bacteria, including Lactobacillus helveticus R0052 inhibit the adhesion of E. coli O157:H7 to epithelial cells, a process which may be related to specific components of the bacterial surface. Surface‐layer proteins (Slps) are located in a paracrystalline layer outside the bacterial cell wall and are thought to play a role in tissue adherence. However, the ability of S‐layer protein extract derived from probiotic bacteria to block adherence of enteric pathogens has not been investigated. Human epithelial (HEp‐2 and T84) cells were treated with S‐layer protein extract alone, infected with E. coli O157:H7, or pretreated with S‐layer protein extract prior to infection to determine their importance in the inhibition of pathogen adherence. The effects of S‐layer protein extracts were characterized by phase‐contrast and immunofluorescence microscopy and measurement of the transepithelial electrical resistance of polarized monolayers. Pre‐treatment of host epithelial cells with S‐layer protein extracts prior to E. coli O157:H7 infection decreased pathogen adherence and attaching‐effacing lesions in addition to preserving the barrier function of monolayers. These in vitro studies indicate that a non‐viable constituent derived from a probiotic strain may prove effective in interrupting the infectious process of an intestinal pathogen.