Page Banner

United States Department of Agriculture

Agricultural Research Service


Location: Molecular Characterization of Foodborne Pathogens Research

Title: Virulence plasmid (pYV)-associated expression of phenotypic virulent determinants in pathogenic Yersinia species: a convenient method for monitoring the presence of pYV under culture conditions and its application

item Bhaduri, Saumya
item Smith, James

Submitted to: Journal of Pathogens
Publication Type: Review Article
Publication Acceptance Date: 6/27/2011
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: In Yersinia pestis, Y. pseudotuberculosis, and Y, enterocolitica, phenotypic expression of several virulence plasmid (pYV: 70-kb)-associated genetic determinants may include low calcium response (Lcr, pin point colony, size = 0.36 mm), colony morphology (size = 1.13 mm), crystal violet (CV) binding (dark-violet colony), Congo Red (CR) uptake (red pin point colony, size = 0.36 mm), autoagglutination (AA = cells agglutinate), and hydrophobicity (HP = clumping of cells). Y. pseudotuberculosis is chromosomally closely related to Y. pestis, whereas, Y. enterocolitica is chromosomally distantly related to Y. pestis and Y. pseudotuberculosis. All three species demonstrate Lcr, CV binding, and CR-uptake. The colony morphology/size, AA, and HP characteristics are expressed in both Y. pseudotuberculosis and Y. enterocolitica, but not in Y. pestis. Congo red-uptake in Y. pestis was demonstrated only on calcium-deficient CR magnesium oxalate tryptic soy agar (CRMOX), whereas this phenotype was expressed on both CRMOX and low-calcium agarose media in Y. pseudotuberculosis and Y. enterocolitica. These phenotypes were detectable at 37 degrees C within 24 h in Y. enterocolitica and Y. pseudotuberculosis, but did not appear until 48 h in Y. pestis due to its slower growth rate at 37 degrees C. The pYV is unstable in all three species but is more unstable in Y. pestis. The specific CR-uptake by Y. pestis in CRMOX and the delayed time interval to express Lcr and CR-uptake provide the means to differentiate Y. pestis from Y. enterocolitica and Y. pseudotuberculosis. These differences in pYV expression in Y. pestis can be used in its isolation and detection from food.

Last Modified: 10/18/2017
Footer Content Back to Top of Page