Pathogenicity of Yersinia kristensenii for mice.
Forty-seven strains of Yersinia kristensenii from widely differing sources, representing all known O serogroups of this species, were investigated for virulence with a variety of animal and in vitro assays. Twenty-four (51%) of the isolates were lethal for mice pretreated with iron dextran. Mouse-lethal strains occurred predominantly within O serogroups O:11, O:12,25, and O:16. Virulent Y. kristensenii strains generally did not express the virulence-associated phenotype (Ca2+ dependence and binding of Congo red and crystal violet) which characterizes virulent strains of Y. enterocolitica, nor did they carry the Yersinia virulence plasmid. Although all strains hybridized with a DNA probe derived from the inv (invasin) gene of Y. enterocolitica, none was able to invade HEp-2 epithelial cell culture. Y. kristensenii strains were virulent only when inoculated parenterally into iron-loaded mice. Animals infected in this way succumbed rapidly to infection, generally within 24 h. This finding suggested that the pathogenicity of these bacteria may be attributable to a secreted toxin, but a search for such a substance and for other in vitro correlates of pathogenicity was unsuccessful. These observations indicate that some strains of Y. kristensenii kill mice by a mechanism not previously recognized in yersiniae.
Robins-Browne
R M
RM
Department of Microbiology, University of Melbourne, Parkville, Victoria, Australia.
Cianciosi
S
S
Bordun
A M
AM
Wauters
G
G
D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis; D003676:Deferoxamine / Q000494:pharmacology; D006168:Guinea Pigs; D007501:Iron / Q000494:pharmacology; D051379:Mice; D014774:Virulence; D015007:Yersinia / Q000276:immunology / Q000472:pathogenicity*
D000942:Antigens, Bacterial; D007501:Iron; D003676:Deferoxamine