Stress Response Mechanisms of Salmonella Enteritidis to Sodium Hypochlorite at the Proteomic Level

Abstract

Salmonella Enteritidis (S. Enteritidis) can adapt to sublethal sodium hypochlorite conditions, which subsequently triggers stress resistance mechanisms in this pathogen. Hence, the current work aimed to reveal the underlying stress adaptation mechanisms in S. Enteritidis by phenotypic, proteomic, and physiological analyses. It was found that 130 ppm sodium hypochlorite resulted in a moderate inhibitory effect on bacterial growth and an increased accumulation of intracellular reactive oxygen species. In response to this sublethal treatment, a total of 492 proteins in S. Enteritidis showed significant differential abundance (p < 0.05; fold change >2.0 or <0.5), including 225 more abundant proteins and 267 less abundant proteins, as revealed by the tandem-mass-tags-based quantitative proteomics technology. Functional characterization further revealed that proteins related to flagellar assembly, two-component system, and phosphotransferase system were in less abundance, while those associated with ABC transporters were generally in more abundance. Specifically, the repression of flagellar-assembly-related proteins led to diminished swimming motility, which served as a potential energy conservation strategy. Moreover, altered abundance of lipid-metabolism-related proteins resulted in reduced cell membrane fluidity, which provided a survival advantage to S. Enteritidis. Taken together, these results indicate that S. Enteritidis employs multiple adaptation pathways to cope with sodium hypochlorite stress.

Comparative secretomic and proteomic analysis reveal multiple defensive strategies developed by Vibrio cholerae against the heavy metal (Cd2+, Ni2+, Pb2+, and Zn2+) stresses

“…For example, the comparative proteomic analysis revealed that the expression of fatty acid biosynthesis-associated proteins was significantly induced in V. cholerae J9-62 under the Pb 2+ stress (p < 0.05). The altered abundance of lipid-metabolism-related proteins likely led to the reduced cell membrane fluidity (Li D. et al, 2022). In addition, cell membrane hydrophobicity affected the activation free energy of passive lipid transport (Rogers et al, 2021).…”

An integrated transcriptome and proteomic investigation of the stress responses of VBNC state Salmonella Enteritidis triggered by sodium hypochlorite

“…[11; 82]. A previous study has revealed stress response mechanisms of S. Enteritidis to NaClO by proteomic [34]. Furthermore, proteomics has also been used in the study of VBNC Escherichia coli O157:H7 induced by low moisture [55].…”