ABSTRACT
The members of the genus Vibrio are a major bacterial population in the marine environment. Although their natural habitat is the marine environment, some species can cause disease in humans through consumption of contaminated seafood or contact with the marine environment. Twelve species are described as clinically important vibrios in Bergey's Manual of Determinative Bacteriology, 9th edition (Holt et al. 1994). Of the seafood-borne pathogenic vibrios, Vibrio cholerae and Vibrio parahaemolyticus represent vibrios that cause enteric infections and Vibrio vulnificus a systemic infection (Tison 1999). A number of studies on these established pathogens have been reported. In addition, seafood-associated enteric infections due to Vibrio mimicus, Vibrio hollisae, Vibrio fluvialis, and possibly due also to Vibrio furnissii were reported much less frequently (Oliver and Kaper 1997). As soon as cloning and nucleotide sequence determination of bacterial genes became possible, this technique was applied to the study of the three major pathogenic Vibrio species to help understand their pathogenic mechanisms. Therefore, the virulenceassociated genes from these species dominate the vibrio genes for which the nucleotide sequences were determined and reported to date. The nucleotide sequences reported from the genes of various Vibrio species encoding other functions are gradually increasing these days. These include the genes useful for the analysis of phylogeny, physiological function of the cellular component, and those that are potentially of industrial use. As the sequencing technology advanced, the entire genome of the clinically important vibrios has become the target of sequence determination.
