title: Vwa+ phenotype of Yersinia enterocolitica.
abstract: Expression of the Vwa+ phenotype of Yersinia pestis in vitro is known to reflect maximum induction of virulence (or V and W antigens) at 37 degrees C with concomitant restriction of cell division. Both phenomena are potentiated by 20 mM Mg2+ and prevented by cultivation at 26 or 37 degrees C with 2.5 mM Ca2+. We have now compared this classic plasmid-mediated phenotype with those of Vwa+ Yersinia pseudotuberculosis and Yersinia enterocolitica which, unlike Y. pestis, produce ancillary outer membrane peptides unrelated to the V and W antigens. All of 10 wild-type strains of Y. enterocolitica (serotypes O:3, O:4,32, O:8, O:9, O:15, and O:21) exhibited a nutritional requirement for Ca2+ at 37 degrees C and produced significant V antigen. Like Y. pseudotuberculosis, autoagglutination of Vwa+ Y. enterocolitica was dependent upon prior growth at 37 degrees C but was not influenced by Ca2+. Autoagglutination of Y. pestis was never observed. Resistance of Y. enterocolitica to 10% human serum was typically dependent upon prior growth at 37 degrees C, either with or without added Ca2+, and carriage of a Vwa plasmid. In contrast, serum resistance of Y. pseudotuberculosis was temperature but not plasmid dependent and that of Y. pestis was constitutive.
mesh_terms: D000371:Agglutination; D000942:Antigens, Bacterial / Q000235:genetics*; D001430:Bacteriocins / Q000494:pharmacology; D001770:Blood Bactericidal Activity; D002118:Calcium / Q000378:metabolism; D006801:Humans; D010641:Phenotype; D014774:Virulence; D015008:Yersinia enterocolitica / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D000942:Antigens, Bacterial; D001430:Bacteriocins; C011330:Pesticin; D002118:Calcium