Effect of organic acids on inhibition of Escherichia coli O157:H7 colonization in gnotobiotic mice associated with infant intestinal microbiota.
Previously, we produced two groups of gnotobiotic mice, GB-3 and GB-4, which showed different responses to Escherichia coli O157:H7 challenge. E. coli O157:H7 was eliminated from GB-3, whereas GB-4 became carriers. In this study, we analysed the mechanisms of E. coli O157:H7 elimination using GB-3 and GB-4. When GB-3 and GB-4 mice were challenged with E. coli O157:H7, the E. coli O157:H7 population was reduced in the caecum of GB-3 when compared to that in the GB-4 caecum, although the numbers of E. coli O157:H7 in the small intestine were not significantly different between these two groups of gnotobiotic mice. The lag time of E. coli O157:H7 growth in a 50% GB-3 caecal suspension increased when compared to that in a GB-4 caecal suspension. Acetate and lactate were detected in the GB-3 caecal contents, and acetate and propionate in those from GB-4. Although E. coli O157:H7 growth was not suppressed when it was cultured in anaerobic broth supplemented with these organic acids, the motility of E. coli O157:H7 was suppressed when it was cultured on semi-solid agar supplemented with the combination of acetate and lactate. These results indicate that the organic acid profile in the caecum is an important factor related to the elimination of E. coli O157:H7 from the intestine.
Momose
Yoshika
Y
Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Hirayama
Kazuhiro
K
Itoh
Kikuji
K
D019342:Acetic Acid / Q000494:pharmacology; D000143:Acids / Q000494:pharmacology*; D000818:Animals; D001647:Bile Acids and Salts / Q000494:pharmacology; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000254:growth & development*; D005260:Female; D005856:Germ-Free Life; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007422:Intestines / Q000382:microbiology*; D019344:Lactic Acid / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D011422:Propionates / Q000494:pharmacology
D000143:Acids; D001647:Bile Acids and Salts; D011422:Propionates; D019344:Lactic Acid; C029658:propionic acid; D019342:Acetic Acid