Characterisation of Vibrio parahaemolyticus isolated from fish in Kenya

Abstract

Background: Acute gastroenteritis associated with fish has been reported since 1951 but is gaining importance with increase in fish consumption in Kenya. The causative agent is Vibrio parahaemolyticus. The importance of this organism is increasing due to the rise in the incidence of outbreaks of food poisoning related to it. Objective: To isolate and characterise local strains of Vibrio parahaemolyticus from sea and fresh-water fish. Design: A prospective study. Setting: Three lakes, a river, a dam and the Kenyan coastline. Subjects: Water and fish samples collected from the study sites. Main outcome measures: Isolation of Vibrio parahaemolyticus on glucose-salt- teepol broth (GTSB), and triphenyltetrazolium chloride soya tryptone (TSAT) and several biochemical media, testing the pathogenicity for the isolates by Kanagawa phenomenon and testing the plasmids profiles, coagglutination sensitivity to antimicrobial substance using standard methods. Results: Twenty nine isolates (4%) were obtained from a total of 666 samples screened, twenty seven of which were isolated from 62 coastal samples. They were Kanagawa negative although their plasmid profiles and sensitivity to antimicrobials varied. Conclusion : There is need to recognise V. parahaemolyticus as a potential problem due to the increase in consumption of fish as an alternative source of protein.