Studies on the Food Poisoning Caused by Vibrio Parahaernolyticus

II. Toxicic dosis of orally administered vibrio to mice and guinea pig

Abstract

Since the comfirmation of Vibrio parahaemoliticus as a causative organims of food poisoning, the disease entity has been extensively investigated, yet leaving many unsolved questions. Mice and guinea pigs were not affected by oral administration of the organism. It was observed, however, that massive dose apparently showed toxicity in them, making possible studies of the questions such as double infection, dosis of organism through oral, or intraperiotneal administration, mortality of mice, histology of the intestinal tract and survival of the organism in the intestine of guinea pigs.
Mice, fasted for 24 hours in winter and given 3 mg wet weight of bacteria showed a death rate of 10/11 and 2/6 by 2 mg. Leucopenia, low body temperature, acute bacteremia with anergic reaction were also observed in them. Survived mice were completely recovered in 48 hours.
In autumn, the dose of bacteria to cause bacteremia by oral admnistration was not found but the toxicity was confirmed. Escherichia coli administered for control did not show any changes.
Histology of the intestinal tract revealed irregularity of villi but no submucosal edema. Double in fection did not aggravate the toxicity. In guinea pigs, 30 minutes after the oral administration of 10 mg wet weight of the bacteriae, most of the bacteriae died in the stomach, but some passed down to the intestine and were possibly transfered into blood stream via lymphatics.
Difference of the clinical manifestations found by Epidemiologic study was thought to be caused by the bacterial dose. Features such as leucocytosis and positive CRP different from common diarrheal diseases seemed to be related to defence mechanism in the infected intestinal wall against the infection.