Characterization of Vibrio mimicus isolated from fish and aquatic environment

Abstract

Vibrio mimicus, a species closely related to Vibrio cholerae, is a type of pathogenic bacteria that causes gastroenteritis in humans and has also been reported as a pathogen inhabiting aquatic environments. It has been isolated from freshwater, brackish water, estuaries, rivers, lakes in tropical and temperate regions. The present study reports isolation, characterization of Vibrio mimicus in samples collected from different landing centers, retail fish markets and aquaculture farms. A total of 42 samples which includes finfish, shellfish, mollusks, dry fish, soil sediment and farm water were screened for this bacterium. Presumptive colonies were confirmed as Vibrio mimicus based on colonial morphology on TCBS agar, Grams’ reaction and other biochemical tests. Further it was confirmed with Polymerase Chain Reaction (PCR) specific for haemolysin gene . The study revealed prevalence of Vibrio mimicus in 4.7% aquaculture samples whereas water and sediment samples didn’t harbour this bacterium. Out of 37 samples screened from retail market and landing centers 16% harboured Vibrio mimicus. Vibrio mimicus is disseminated in the aquatic environment through fish and may transfer to water birds that consume them. Thus fish are reservoirs of Vibrio mimicus and may play an important role in its global spread. Reports indicate gastrointestinal disorders caused by the contamination of raw and improper cooked Vibrio mimicus contaminated fish. This study asks for preventive measures to avoid health hazards caused by Vibrio mimicus.