Growth of Yersinia pseudotuberculosis Strains at Different Temperatures, pH Values, and NaCl and Ethanol Concentrations

ABSTRACT Maximum growth temperature and growth limits in Luria-Bertani broth at different pH values and NaCl and ethanol concentrations were determined for 49 Yersinia pseudotuberculosis strains representing serotypes O:1, O:2, O:3, O:4, and O:5. In addition, the ability of the strains to grow at 0°C and the growth parameters at 1°C were determined. The maximum growth temperatures measured by Gradiplate temperature incubator varied between 42.2 and 43.7°C. All strains were able to grow at 0°C in Luria-Bertani broth within 17 days of incubation. At 1°C, differences were observed among strains in the maximum growth rates and area under the curve values based on optical density data, which suggests that some Y. pseudotuberculosis strains adapt faster to colder conditions. The mean maximum growth rates and area under the curve values at 1°C, as well as the mean maximum growth temperatures, were statistically significantly higher among serotype O:1 strains compared with O:3 strains and among biotype 1 compared...