Ferrous sulfate efficiently kills Vibrio parahaemolyticus and protects salmon sashimi from its contamination.

The primary seafood-borne pathogen Vibrio parahaemolyticus seriously threats the health of consumers preferring raw-fish products, becoming a global concern in food safety. In the present study, we found ferrous sulfate (FeSO ₄ ), a nutritional iron supplement, could efficiently induce the death of V. parahaemolyticus. Further, the bactericidal mechanisms of FeSO ₄ were explored. With a fluorescent probe of Fe ²⁺ , a significant influx of Fe ²⁺ was determined in V. parahaemolyticus exposed to FeSO ₄ , and the addition of an intracellular Fe ²⁺ chelator was able to block the cell death. This suggested that cell death in V. parahaemolyticus induced by FeSO ₄ was dependent on the influx of Fe ²⁺ . It was intriguing that we did not observe the eruption of reactive oxygen species (ROS) and lipid hydroperoxides by Fe ²⁺ , but the application of liproxstatin-1 (a ferroptosis inhibitor) significantly modified the occurrence of cell death in V. parahaemolyticus. These results suggested FeSO ₄ -induced cell death in V. parahaemolyticus be a ferroptosis differing from that in mammalian cells. Through transcriptome analysis, it was discovered that the exposure of FeSO ₄ disturbed considerable amounts of gene expression in V. parahaemolyticus including those involved in protein metabolism, amide biosynthesis, two-component system, amino acid degradation, carbon metabolism, citrate cycle, pyruvate metabolism, oxidative phosphorylation, and so on. These data suggested that FeSO ₄ was a pleiotropic antimicrobial agent against V. parahaemolyticus. Notably, FeSO ₄ was able to eliminate V. parahaemolyticus in salmon sashimi as well, without affecting the color, texture, shearing force, and sensory characteristics of salmon sashimi. Taken together, our results deciphered a unique ferroptosis in V. parahaemolyticus by FeSO ₄ , and highlighted its potential in raw-fish products to control V. parahaemolyticus.
Competing Interests: Declaration of competing interest The authors (Yanyan Zhao, Xiaofeng Kang, Wei Zhou, Jintae Lee，Shuyan Wang, Zhenkun Cui, Hao Zhang, Haizhen Mo, Liangbin Hu) declare that there are no financial interests or personal relationships that will influence the work reported in this paper.
(Copyright © 2022. Published by Elsevier B.V.)