title: The effect of Lactobacillus rhamnosus on enterohemorrhagic Escherichia coli infection of human intestinal cells in vitro.
abstract: There are many examples of probiotic effects of various lactic bacteria on enteropathogens. In this study, Lactobacillus strains (L. rhamnosus, L. gasseri, L. casei and L. plantarum) were tested in an in vitro model of enterohemorrhagic Escherichia coli (EHEC) infection of a human colon epithelial cell line, C2BBe1. While the adhesion and colonization of EHEC was not affected by any of the lactobacillus strains tested, the internalization of EHEC into the cell line was markedly suppressed by L. rhamnosus, though not by others. Concerning the possible mechanisms, the viabilities of EHEC and host cell were not affected by the presence of L. rhamnosus. Simple competitions at certain receptors were unlikely because the suppressive effect on EHEC internalization was strictly dependent on viable L. rhamnosus and could not be observed with the conditioned medium or killed L. rhamnosus. The fact that L. rhamnosus showed outstanding potential for adhering to the colon epithelial cell line, compared with other strains, suggested that an avid interaction between L. rhamnosus and the host cell might be modulating intra-cellular events responsible for the internalization of EHEC.
authors.affiliation: School of Nutritional Sciences, Nagoya University of Arts and Sciences, Nagoya, Aichi 470-0196, Japan.
authors.forename: Jyunko
authors.initials: J
authors.lastname: Hirano
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yoshida
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Naoki
authors.initials: N
authors.lastname: Koide
authors.forename: Isamu
authors.initials: I
authors.lastname: Mori
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokochi
mesh_terms: D001422:Bacterial Adhesion; D002478:Cells, Cultured / Q000187:drug effects / Q000382:microbiology; D003106:Colon / Q000166:cytology* / Q000382:microbiology; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000382:microbiology; D019453:Escherichia coli O157 / Q000502:physiology*; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology* / Q000382:microbiology; D007778:Lactobacillus / Q000502:physiology*; D019936:Probiotics; D013045:Species Specificity
chemical_list: D017077:Culture Media, Conditioned