A susceptible protein by proteomic analysis from Vibrio anguillarum under various environmental conditions.

Vibrio anguillarum is a halophilic Gram-negative bacterium causing vibriosis in marine fish and other aquatic animals. Most bacteria have developed strategies to survive in harsh environments, and V. anguillarum also encounters various stresses in seawater and hosts. In this study, we investigated changes in protein expression of V. anguillarum in response to diverse stress conditions of temperature, pH, and NaCl. Proteins were separated by 2D-PAGE, differences in expression patterns under each of the above conditions were observed, and proteins were identified using MALDI-TOF MS/MS. We found an oxidoreductase short-chain dehydrogenase/reductase family protein (OSDR), commonly down-regulated under all applied stresses (temperature 15 °C, pH 5 or 10, and NaCl 2 M). Analysis at transcriptional level using RT-PCR showed that osdr gene expression was reduced over time under these stress conditions. Among the various stresses, pH 10 was the most effective for reduction of osdr mRNA transcription. Our findings provide a useful candidate protein for detection of environmental change using V. anguillarum.