A large outbreak of foodborne infection attributed to Providencia alcalifaciens

The enteropathogenicity of Providencia alcalifaciens, a member of the famil y Enterobacteriaceae, has not yet been well established. In November 1996, a large outbreak of foodborne infection occurred in Fukui, Japan. In this s tudy, the etiology of the outbreak was investigated. No other recognized en teropathogens were detected in patient fecal samples, but P. alcalifaciens was detected in 7 of 18 samples. The isolates were found to be clonal by pu lsed-field gel electrophoresis. The patients who presented with gastroenter itis had elevated levels of specific antibody against the isolated P. alcal ifaciens. The isolates showed invasion of Caco-2 cells and fluid accumulati on in rabbit ileal loops. This study strongly suggests that the outbreak wa s caused by P. alcalifaciens. This is the first report of a large outbreak of foodborne infection attributed to the organism and provides definitive e vidence that P. alcalifaciens is a causative agent of gastroenteritis.