BACTERIOLOGICAL STUDY ON VIBRIO PARAHAEMOLYTICUS ISOLATED FROM THE OUTBREAKS OF DIARRHEA IN LAOS, AN INLAND COUNTRY

An epidemic of Vibrio parahaemolyticus gastroenteritis with several outbreaks occurred in Vientiane, People's Democratic Republic of Lao (Laos), an inland country in August and September in 1997. Serotypes of the 36 isolated V.parahaemolyticus strains from the patients were all O3 : K6. The organisms grew in peptone water supplemented with 10%NaCl. All isolates were positive for Kanagawa phenomenon, and they were positive for tdh, negative for trh and urease. Genomic patterns were not completely identical, as determined by pulsed-field gel electrophoresis. The causative food was suspected to be a papaya salad containing minced and salted fresh water crab. Although a Kanagawa phenomenon positive V.parahaemolyticus strain was isolated from the suspicious food, the serotype was O2 : K28, tdh and trh were negative.