Hydrophobicity, cell adherence, cytotoxicity, and enterotoxigenicity of starved Vibrio parahaemolyticus

Abstract

Vibrio parahaemolyticus is a ubiquitous gram-negative enteropathogenic bacterium that may encounter starvation or other environmental stresses during food processing or human infection. Pathogenic V. parahaemolyticus ST550 cultures starved in modified Morita mineral salt solution with 3 or 0.5% NaCl exhibited similar resistance against challenges of environmental stresses. Changes in virulence of the starved V. parahaemolyticus was determined using HEp-2 cell culture and suckling mouse assay. The starved cells exhibited greater cell adherence and hydrophobicity than did the cells in exponential growth phase. Expression of virulence in terms of cytotoxicity and mouse lethality was lower in the starved cells than in the exponential-phase cells at the same postinfection time. An additional 1 h of in vitro or in vivo incubation was required to enable these starved cells to reach the same cytotoxicity and mouse lethality levels as exhibited by the exponential-phase cells.