Synergistic interaction of baker's yeast and iron in the enhancement of bacterial virulence.
The virulence-enhancing interaction of baker's yeast and different iron preparations (ferric ammonium citrate and iron dextran) was tested in mice challenged with Salmonella typhi and Vibrio cholerae (Inaba and Ogawa) strains. The virulence-enhancing effect of the yeast + iron combination increased significantly as compared to that of either yeast or iron alone. Toxicity assays of the single and combined baker's yeast and iron preparations by the mouse weight gain test have shown that the combinations are considerably more toxic than either single agent, probably owing to the presence of yeast. Examination of the single and combined preparations for influence on body temperature of mice has revealed a general hypothermic action, which was strongest in the combinations, owing again to the yeast. Theoretical considerations on the underlying mechanism of the virulence-enhancing effect have supported the hypothesis that the effect might be associated with the strong hypothermic action produced by baker's yeast and baker's yeast + iron combinations, in as much as hypothermia increases the production of siderophores which ensure the acquisition of iron indispensable for bacterial growth.
D000818:Animals; D002771:Cholera / Q000382:microbiology*; D005290:Ferric Compounds / Q000494:pharmacology*; D007501:Iron / Q000494:pharmacology*; D007505:Iron-Dextran Complex / Q000494:pharmacology*; D051379:Mice; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D012485:Salmonella typhi / Q000187:drug effects / Q000472:pathogenicity*; D014435:Typhoid Fever / Q000382:microbiology*; D014734:Vibrio cholerae / Q000187:drug effects / Q000472:pathogenicity*; D014774:Virulence / Q000187:drug effects
D005290:Ferric Compounds; D000644:Quaternary Ammonium Compounds; D007505:Iron-Dextran Complex; D007501:Iron; C013531:ferric ammonium citrate