Proteomic analysis reveals responsive proteins of Vibrio parahaemolyticus on exposure to cationic antimicrobial peptides

Aims: To investigate whether Vibrio parahaemolyticus can sense and directly respond to the presence of cationic antimicrobial peptides (AMPs). Methods and Results: We performed proteomic methodologies to investigate the responsive proteins of V. parahaemolyticus on exposure to AMP Q6. Differential expression patterns of the outer membrane, inner membrane and cytoplasmic proteins (OMPs, IMPs and CPs) from the bacteria with or without Q6 treatment were obtained using two‐dimensional gel electrophoresis (2‐DE). Three OMPs (maltoporin, flagellin and OmpV), two IMPs (ATP synthase F1, alpha subunit; and OmpV) and three CPs (pyruvate dehydrogenase subunit E1, glyceraldehyde‐3‐phosphate dehydrogenase and inositol‐5‐monophosphate dehydrogenase) were identified using LC‐ESI‐Q‐TOF MS/MS and Mascot program. Real‐time quantitative polymerase chain reaction was also performed to determine the mRNA expression level of the target genes. Conclusions: Our results suggested that V. parahaemolyticus may directly respond to AMPs through the upregulation of the efflux channel, increased yield of energy, effective repair of damaged membranes and downregulation of carbohydrate and nucleotide metabolism for energy preservation. Significance and Impact of the Study: AMP‐responsive proteins identified in the current study could serve as attractive targets for developing more effective antimicrobial agents.