This study investigated whether sodium hypochlorite(NaClO)can induce Vibrio parahaemolyticus(Vp)into viable but nonculturable(VBNC)state and change its characteristics.When exposed to 40 mg/L chlorine for 20 min,plate...This study investigated whether sodium hypochlorite(NaClO)can induce Vibrio parahaemolyticus(Vp)into viable but nonculturable(VBNC)state and change its characteristics.When exposed to 40 mg/L chlorine for 20 min,plate counts decreased from 10^(6)CFU/mL to undetectable but fluorescent staining indicated that 11.94±1.24%of cells still remained viable,suggesting that Vp had entered a VBNC state.Light microscopy showed that VBNC-Vp cells had changed from a short rod-shape to coccoid with a rough surface,aggregation,and additional ma-terial in the intercellular spaces.In VBNC-Vp cells,intracellular pHi and respiratory activity were lower than in normal cells and the ATP concentration was 81.25±1.64%in normal cells.VBNC-Vp cells exhibited lower surface zeta potential and reduced adhesion and invasion capacity compared to normal cells but their ability to survive in food-associated stresses was markedly enhanced.RT-qPCR results revealed that changes in morphology,metabolism,and adhesion of VBNC-Vp cells may be due to down-regulation of mreB,cysD,atpA,ompA,flaA,and flgM genes.The potential adversity-resistant capacity of VBNC-Vp cells were due to soxR and katG up-regulation.Overall,NaClO induced Vp into a VBNC state,thereby altering its biological properties to withstand adverse conditions.展开更多
基金The National Natural Science Foundation of China(32201929,32202134)2025 Guangdong Basic and Applied Basic Research Foundation of Natural Science Foundation project(2025A1515011748)High-level talent Project of Lingnan Normal University(ZL2415)supported this study.
文摘This study investigated whether sodium hypochlorite(NaClO)can induce Vibrio parahaemolyticus(Vp)into viable but nonculturable(VBNC)state and change its characteristics.When exposed to 40 mg/L chlorine for 20 min,plate counts decreased from 10^(6)CFU/mL to undetectable but fluorescent staining indicated that 11.94±1.24%of cells still remained viable,suggesting that Vp had entered a VBNC state.Light microscopy showed that VBNC-Vp cells had changed from a short rod-shape to coccoid with a rough surface,aggregation,and additional ma-terial in the intercellular spaces.In VBNC-Vp cells,intracellular pHi and respiratory activity were lower than in normal cells and the ATP concentration was 81.25±1.64%in normal cells.VBNC-Vp cells exhibited lower surface zeta potential and reduced adhesion and invasion capacity compared to normal cells but their ability to survive in food-associated stresses was markedly enhanced.RT-qPCR results revealed that changes in morphology,metabolism,and adhesion of VBNC-Vp cells may be due to down-regulation of mreB,cysD,atpA,ompA,flaA,and flgM genes.The potential adversity-resistant capacity of VBNC-Vp cells were due to soxR and katG up-regulation.Overall,NaClO induced Vp into a VBNC state,thereby altering its biological properties to withstand adverse conditions.
