The isolation of urease-negative strains of Yersinia enterocolitica.

Three urease-negative Y. enterocolitica strains of biotype 2 have been isolated from stool and urine of healthy persons. They were diagnosed on an isolation medium used routinely in the bacteriological laboratory of the Regional Station of Hygiene in Ceské Budĕjovice for isolation and diagnosis of gram-negative facultatively anaerobic-fermenting rods. An important characteristic was the smell of the culture, typical of all the indole-positive strains of Y. enterocolitica.