Production of enterotoxin by Yersinia enterocolitica.

Forty-three strains of Yersinia enterocolitica isolated from children with gastroenteritis and 18 laboratory strains were examined for enterotoxin production by using the infant mouse, Y1 adrenal cell, and rabbit ileal loop assay systems. All clinical isolates and seven laboratory strains were found enterotoxigenic in the infant mouse model, but none of the strains produced toxin in the Y1 adrenal cell system. One enterotoxin-producing strain was also tested by the rabbit ileal loop assay, confirming the results of the infant mouse assay. The enterotoxin was heat-stable and as active in the 6-h rabbit ileal loop as in the 18-h assay, suggesting a similarity to the heat-stable enterotoxin of Escherichia coli.