title: Identification of Novel Components Influencing Colonization Factor Antigen I Expression in Enterotoxigenic Escherichia coli.
abstract: Colonization factors (CFs) mediate early adhesion of Enterotoxigenic Escherichia coli (ETEC) in the small intestine. Environmental signals including bile, glucose, and contact with epithelial cells have previously been shown to modulate CF expression in a strain dependent manner. To identify novel components modulating CF surface expression, 20 components relevant to the intestinal environment were selected for evaluation. These included mucin, bicarbonate, norepinephrine, lincomycin, carbon sources, and cations. Effects of individual components on surface expression of the archetype CF, CFA/I, were screened using a fractional factorial Hadamard matrix incorporating 24 growth conditions. As most CFs agglutinate erythrocytes, surface expression was evaluated by mannose resistant hemagglutination. Seven components, including porcine gastric mucin, lincomycin, glutamine, and glucose were found to induce CFA/I surface expression in vitro in a minimal media while five others were inhibitory, including leucine and 1,10-phenanthroline. To further explore the effect of components positively influencing CFA/I surface expression, a response surface methodology (RSM) was designed incorporating 36 growth conditions. The optimum concentration for each component was identified, thereby generating a novel culture media, SP1, for CFA/I expression. CFs closely related to CFA/I, including CS4 and CS14 were similarly induced in SP1 media. Other epidemiologically relevant CFs were also induced when compared to the level obtained in minimal media. These results indicate that although CF surface expression is complex and highly variable among strains, the CF response can be predicted for closely related strains. A novel culture media inducing CFs in the CF5a group was successfully identified. In addition, mucin was found to positively influence CF expression in strains expressing either CFA/I or CS1 and CS3, and may function as a common environmental cue.
authors.affiliation: Research Department, Sanofi Pasteur, Marcy-l'Étoile, France; UMR5240 CNRS/INSA/UCB, Université de Lyon 1, Villeurbanne, France, INSA-Lyon, Villeurbanne, France.
authors.forename: Sara
authors.initials: S
authors.lastname: Haines
authors.affiliation: Research Department, Sanofi Pasteur, Marcy-l'Étoile, France.
authors.forename: Sylviane
authors.initials: S
authors.lastname: Gautheron
authors.affiliation: UMR5240 CNRS/INSA/UCB, Université de Lyon 1, Villeurbanne, France, INSA-Lyon, Villeurbanne, France.
authors.forename: William
authors.initials: W
authors.lastname: Nasser
authors.affiliation: Research Department, Sanofi Pasteur, Marcy-l'Étoile, France.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Renauld-Mongénie
mesh_terms: D018829:Adhesins, Bacterial / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D001422:Bacterial Adhesion; D001427:Bacterial Toxins / Q000032:analysis; D001431:Bacteriological Techniques; D002417:Cattle; D002473:Cell Wall / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology*; D054307:Enterotoxigenic Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity; D004768:Enterotoxins / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D029968:Escherichia coli Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D036781:Fimbriae Proteins / Q000096:biosynthesis* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D005973:Glutamine / Q000494:pharmacology; D006386:Hemagglutination Tests; D006801:Humans; D007422:Intestines / Q000737:chemistry / Q000382:microbiology; D008034:Lincomycin / Q000494:pharmacology; D009077:Mucins / Q000494:pharmacology; D034421:Sus scrofa; D013552:Swine; D014774:Virulence / Q000187:drug effects
chemical_list: D018829:Adhesins, Bacterial; D001427:Bacterial Toxins; D003470:Culture Media; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D009077:Mucins; C022924:colonization factor antigens; D005973:Glutamine; D036781:Fimbriae Proteins; D008034:Lincomycin; C027538:heat-labile enterotoxin, E coli