[Enteropathogenicity of Providencia alcalifaciens, a newly recognized pathogen causing food-poisoning]

Providencia alcalifaciens, a member of the family Enterobacteriaceae, has been thought to be a normal flora or an opportunistic pathogen. In 1996, a large outbreak (including 270 patients) of acute gastroenteritis occurred in Fukui. No known enteropathogens were detected in fecal samples of the patients, but P. alcalifaciens was detected from 7 of the 18 samples. The isolates were a clonal by pulsed-field gel electrophoresis. The specific antibody against the isolated strain was elevated in the patients' sera. The isolates showed invasiveness into Caco-2 cells and fluid-accumulation in rabbit ileal loops. These results indicate that P. alcalifaciens can be one of the causative agents of gastroenteritis or food-poisoning.