Correlation between medium acidification and pathogenicity in environmental halophilic non-cholera vibrios.

Aims: The metabolic characterization and pathogenicity of vibrios isolated from seafood were studied.
Methods and Results: Strains of halophilic vibrios, grown in the presence of 0.5% glucose, induced high medium acidification and were non-culturable after 24 h, while moderately acidifying strains were culturable, produced cytotoxins, and remained lethal when inoculated intraperitoneally in mice. Highly acidifying strains failed to elicit pathogenicity in vivo and in vitro.
Conclusion: The high acidification of the medium and the self-killing activity of NCVs might be considered a significant phenotypic marker of virulence and/or cytotoxicity.
Significance and Impact of the Study: We suggest the medium acidification test as possible screening method for pathogenic NCVs in food microbiology.