Identification of a phosphoethanolamine transferase for lipid A modification in Vibrio parahaemolyticus

Abstract Vibrio parahaemolyticus is a foodborne pathogen and naturally resistant to polymyxins, the last line of therapy for infections caused by multidrug-resistant bacteria. Polymyxins resistance is typically facilitated by the modification of phosphoethanolamine group on the lipid A of lipopolysaccharide in Gram-negative bacteria. In this study, we found that VP_RS21300 encodes a phosphoethanolamine transferase in V. parahaemolyticus ATCC33846. Deletion of VP_RS21300 in ATCC33846 resulted in the defection of phosphoethanolamine addition to lipid A. Furthermore, VP_RS21300 could recover the modification of phosphoethanolamine to lipid A in E. coli MG1655ΔeptA. In addition, when mouse RAW264.7 cells were infected by ATCC33846 and ATCC33846ΔRS2130, and the survival rate of ATCC33846ΔRS21300 was much higher than that of ATCC33846. The results suggest that VP_RS21300 encodes a phosphoethanolamine transferase for lipid A in V. parahaemolyticus and plays an important role on polymyxins resistance and pathogenicity.