Comparison of siderophore production and utilization in pathogenic and environmental isolates of Yersinia enterocolitica.

Yersinia enterocolitica strains of serotypes lethal to mice have been reported previously to produce an endogenous siderophore. In this study, an ethyl acetate-extractable siderophore was characterized and given the name yersiniophore. Yersiniophore was produced by 16 of 16 human isolates of serotypes O:4, O:4,32, O:8, O:21, and one nonhuman isolate of serotype O:21. It was not produced by isolates of serotype O:3, O:5, or O:9. One strain of Yersinia pseudotuberculosis produced yersiniophore, but strains of Yersinia kristensenii, Yersinia frederiksenii, and Yersinia intermedia did not produce or utilize yersiniophore. Food and water isolates of Y. enterocolitica produced a water-soluble siderophore but not yersiniophore. Sixty-two strains of Y. enterocolitica including 42 isolates from human infections, 2 animal isolates, and 18 water and food isolates were examined for utilization of yersiniophore, the water-soluble siderophore, and ferrioxamine. Yersiniophore promoted growth rate, iron binding, and uptake in 17 of 62 strains, all of which produced yersiniophore. Ten of 17 food and water isolates and one human isolate were capable of utilizing the water-soluble siderophore. Utilization studies suggest that at least one additional water-soluble siderophore may be produced. Ferrioxamine promoted the growth of 60 of 62 strains examined; however, only the 17 strains which produced yersiniophore actively accumulated [59Fe]ferrioxamine. Yersiniophore production and utilization may be important in clinical infections since all human strains belonging to serotype O:8 produced yersinophore. The water-soluble siderophore was not detected in human isolates.