Detection of pathogenic Yersinia enterocolitica by using congo red-magnesium oxalate agar medium

A Congo red-magnesium oxalate agar medium was developed to detect expression of virulence-associated calcium dependency and Congo red absorption in Yersinia enterocolitica. Of the 157 pathogenic serotypes tested, 119 (75.8%) were positive; 98% of nonpathogenic serotypes and strains of three other Yersinia species were negative.