Faculty Opinions recommendation of The ABC-type efflux pump MacAB protects Salmonella enterica serovar typhimurium from oxidative stress.

2014 ◽  
Author(s):  
David Stephens ◽  
Scott Chancey
Keyword(s):  
Oxidative Stress ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Efflux Pump ◽  
Serovar Typhimurium

scholarly journals Sub-Inhibitory Fosmidomycin Exposures Elicits Oxidative Stress in Salmonella enterica Serovar typhimurium LT2

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e95271 ◽  
Author(s):  
David T. Fox ◽  
Emily N. Schmidt ◽  
Hongzhao Tian ◽  
Suraj Dhungana ◽  
Michael C. Valentine ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Serovar Typhimurium

DsrA confers resistance to oxidative stress in Salmonella enterica serovar Typhimurium

Food Control ◽  
2021 ◽  
Vol 121 ◽  
pp. 107571
Author(s):  
Rui Dong ◽  
Xiaojie Qin ◽  
Shoukui He ◽  
Xiujuan Zhou ◽  
Yan Cui ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Serovar Typhimurium

scholarly journals Ciprofloxacin-Resistant Salmonella enterica Serovar Typhimurium Strains Are Difficult To Select in the Absence of AcrB and TolC

2006 ◽  
Vol 50 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Vito Ricci ◽  
Peter Tzakas ◽  
Anthony Buckley ◽  
Nick C. Coldham ◽  
Laura J. V. Piddock
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Efflux Pump ◽  
Multiple Antibiotic Resistance ◽  
Efflux System ◽  
Efflux Pump Inhibitor ◽  
Serovar Typhimurium ◽  
Resistant Mutants ◽  
Selection Of ◽  
Selection Of Resistance

ABSTRACT It has been proposed that lack of a functional efflux system(s) will lead to a lower frequency of selection of resistance to fluoroquinolones and other antibiotics. We constructed five strains of Salmonella enterica serovar Typhimurium SL1344 that lacked efflux gene components of resistance nodulation cell division pumps (acrB, acrD, acrF, acrBacrF, and tolC) plus three strains that lack genes that effect efflux gene expression (marA, soxS, and ramA) and a hypermutable strain (mutS::aph). Strains were exposed to ciprofloxacin at 2× the MIC in agar, in the presence and absence of Phe-Arg-β-naphthylamide, an efflux pump inhibitor. Mutants were selected from all strains except those lacking acrB, tolC, or acrBacrF. For strains from which mutants were selected, there were no significant differences between the frequencies of resistance. Except for mutants of the ramA::aph strain, two phenotypes arose: resistance to quinolones only and multiple antibiotic resistance (MAR). ramA::aph mutants were resistant to quinolones only, suggesting a role for ramA in MAR in S. enterica serovar Typhimurium. Phe-Arg-β-naphthylamide (20 μg/ml) had no effect on the frequencies of resistance or ciprofloxacin MICs. In conclusion, functional AcrB and TolC in S. enterica serovar Typhimurium are important for the selection of ciprofloxacin-resistant mutants.

scholarly journals The Ferritin-Like Dps Protein Is Required for Salmonella enterica Serovar Typhimurium Oxidative Stress Resistance and Virulence

2004 ◽  
Vol 72 (2) ◽  
pp. 1155-1158 ◽  
Author(s):  
Thomas A. Halsey ◽  
Andrés Vazquez-Torres ◽  
Daniel J. Gravdahl ◽  
Ferric C. Fang ◽  
Stephen J. Libby
Keyword(s):  
Oxidative Stress ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Bacterial Species ◽  
Phagocytic Cells ◽  
Evolutionarily Conserved ◽  
Serovar Typhimurium ◽  
Environmental Bacteria ◽  
Dps Protein

ABSTRACT Resistance to phagocyte-derived reactive oxygen species is essential for Salmonella enterica serovar Typhimurium pathogenesis. Salmonella can enhance its resistance to oxidants through the induction of specific genetic pathways controlled by SoxRS, OxyR, σS, σE, SlyA, and RecA. These regulons can be found in a wide variety of pathogenic and environmental bacteria, suggesting that evolutionarily conserved mechanisms defend against oxidative stress both endogenously generated by aerobic respiration and exogenously produced by host phagocytic cells. Dps, a ferritin-like protein found in many eubacterial and archaebacterial species, appears to protect cells from oxidative stress by sequestering iron and limiting Fenton-catalyzed oxyradical formation. In Escherichia coli and some other bacterial species, Dps has been shown to accumulate during stationary phase in a σS-dependent fashion, bind nonspecifically to DNA, and form a crystalline structure that compacts and protects chromatin from oxidative damage. In the present study, we provide evidence that Dps protects Salmonella from iron-dependent killing by hydrogen peroxide, promotes Salmonella survival in murine macrophages, and enhances Salmonella virulence. Reduced numbers of dps mutant bacteria in the livers and spleens of infected mice are consistent with a role of Dps in protecting Salmonella from oxidative stress encountered during infection.

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