Membrane fatty acids composition and fluidity modification in <i>Salmonella</i> Typhimurium by culture temperature and resistance under pulsed electric fields

Wang, Ruo‐Yong; Yun, Ou; Zeng, Xin‐An; Guo, Chang‐Jiang

doi:10.1111/ijfs.14137

Cited by 9 publications

(1 citation statement)

References 37 publications

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“…Thus, the mutant strain lacking the catalases and reductases accumulates ROS in a more rapid manner downregulating the expression and the function of efflux pumps, and so causing terminal damage to the cell envelope. Other studies show that, under exogenous stress, Salmonella Typhimurium modifies its outer membrane fatty acid composition, increasing unsaturated oleic and linoleic acid and resulting in enhanced fluidity of the cellular membrane that affects permeabilization [63,64]. This is in accordance with our results when analysing the high degree of lipid peroxidation of the mutant strain in comparison with its parental strain (Figure 6).…”

Section: Supplementary Materialssupporting

confidence: 92%

Role of Platinum Nanozymes in the Oxidative Stress Response of Salmonella Typhimurium

et al. 2023

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Platinum nanoparticles (PtNPs) are being intensively explored as efficient nanozymes due to their biocompatibility coupled with excellent catalytic activities, which make them potential candidates as antimicrobial agents. Their antibacterial efficacy and the precise mechanism of action are, however, still unclear. In this framework, we investigated the oxidative stress response of Salmonella enterica serovar Typhimurium cells when exposed to 5 nm citrate coated PtNPs. Notably, by performing a systematic investigation that combines the use of a knock-out mutant strain 12023 HpxF- with impaired response to ROS (ΔkatE ΔkatG ΔkatN ΔahpCF ΔtsaA) and its respective wild-type strain, growth experiments in both aerobic and anaerobic conditions, and untargeted metabolomic profiling, we were able to disclose the involved antibacterial mechanisms. Interestingly, PtNPs exerted their biocidal effect mainly through their oxidase-like properties, though with limited antibacterial activity on the wild-type strain at high particle concentrations and significantly stronger action on the mutant strain, especially in aerobic conditions. The untargeted metabolomic analyses of oxidative stress markers revealed that 12023 HpxF- was not able to cope with PtNPs-based oxidative stress as efficiently as the parental strain. The observed oxidase-induced effects comprise bacterial membrane damage as well as lipid, glutathione and DNA oxidation. On the other hand, in the presence of exogenous bactericidal agents such as hydrogen peroxide, PtNPs display a protective ROS scavenging action, due to their efficient peroxidase mimicking activity. This mechanistic study can contribute to clarifying the mechanisms of PtNPs and their potential applications as antimicrobial agents.

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Section: Supplementary Materialssupporting

confidence: 92%