ZntR modulates zinc homeostasis, oxidative stress resistance, and virulence of Vibrio parahaemolyticus

Abstract:

[Objective] To explore the regulatory role of the metalloregulator ZntR in metal homeostasis and clarify the effects of ZntR on the oxidative stress resistance and virulence of Vibrio parahemolyticus. [Methods] Growth curve analysis and intracellular metal content quantification were performed to investigate the regulatory effect of ZntR on the metal homeostasis in V. parahaemolyticus. The effects of ZntR on the oxidative stress resistance and virulence of V. parahaemolyticus were explored by the growth curve analysis and the competitive infection assay in the zebrafish model, respectively. The genes regulated by ZntR were identified by RNA sequencing. [Results] The zntR-deleted strain (ΔzntR) exhibited growth defects under zinc, nickel excess and iron restriction conditions, and the growth defects were related to zinc homeostasis disturbance. The overexpression of zntA in ΔzntR promoted the growth under zinc, nickel excess and iron restriction conditions. In the case of zinc excess, ΔzntR demonstrated weakened resistance to H₂O₂-induced oxidative stress. The virulence of ΔzntR was attenuated in a competitive infection assay in the zebrafish model. RNA sequencing revealed that ZntR regulated the expression of several virulence genes. [Conclusion] ZntR modulates zinc homeostasis and improves oxidative stress resistance and virulence of V. parahaemolyticus.