Please use this identifier to cite or link to this item: https://doi.org/10.1128/AEM.70.6.3500-3505.2004
Title: Adaptation of Escherichia coli O157:H7 to pH alters membrane lipid composition, verotoxin secretion, and resistance to simulated gastric fluid acid
Authors: Yuk, H.-G 
Marshall, D.L
Keywords: Cells
Composition
Genes
Lipids
Membranes
Organic acids
pH
Gastric fluids
Membrane fluidity
Escherichia coli
membrane lipid
palmitic acid
vaccenic acid
verotoxin
microbiology
adaptation
article
bacterial survival
bacterial virulence
bacterium mutant
cell membrane fluidity
Escherichia coli
hemolytic uremic syndrome
hemorrhagic colitis
lipid composition
nonhuman
stomach acid
stomach pH
thrombotic thrombocytopenic purpura
toxin synthesis
Adaptation, Physiological
Drug Resistance, Bacterial
Escherichia coli
Escherichia coli O157
Gastric Acid
Humans
Hydrogen-Ion Concentration
Membrane Lipids
Shiga Toxins
Bacteria (microorganisms)
Escherichia coli
Negibacteria
Purpura
Issue Date: 2004
Citation: Yuk, H.-G, Marshall, D.L (2004). Adaptation of Escherichia coli O157:H7 to pH alters membrane lipid composition, verotoxin secretion, and resistance to simulated gastric fluid acid. Applied and Environmental Microbiology 70 (6) : 3500-3505. ScholarBank@NUS Repository. https://doi.org/10.1128/AEM.70.6.3500-3505.2004
Rights: Attribution 4.0 International
Abstract: The influence of adaptation to pH (from pH 5.0 to 9.0) on membrane lipid composition, verotoxin concentration, and resistance to acidic conditions in simulated gastric fluid (SGF) (pH 1.5, 37°C) was determined for Escherichia coli O157:H7 (HEC, ATCC 43895), an rpoS-deficient mutant of ATCC 43895 (HEC-RM, FRIK 816-3), and nonpathogenic E. coli (NPEC, ATCC 25922). Regardless of the strain, D values (in SGF) of acid-adapted cells were higher than those of non-acid-adapted cells, with HEC adapted at pH 5.0 having the greatest D value, i.e., 25.6 min. Acid adaptation increased the amounts of palmitic acid (C16:0) and decreased cis-vaccenic acid (C18:?7c) in the membrane lipids of all strains. The ratio of cis-vaccenic acid to palmitic acid increased at acidic pH, causing a decrease in membrane fluidity. HEC adapted to pH 8.3 and HEC-RM adapted to pH 7.3 exhibited the greatest verotoxin concentrations (2,470 and 1,460 ng/ml, respectively) at approximately 108 CFU/ml. In addition, the ratio of extracellular to intracellular verotoxin concentration decreased at acidic pH, possibly due to the decrease of membrane fluidity. These results suggest that while the rpoS gene does not influence acid resistance in acid-adapted cells it does confer decreased membrane fluidity, which may increase acid resistance and decrease verotoxin secretion.
Source Title: Applied and Environmental Microbiology
URI: https://scholarbank.nus.edu.sg/handle/10635/181107
ISSN: 00992240
DOI: 10.1128/AEM.70.6.3500-3505.2004
Rights: Attribution 4.0 International
Appears in Collections:Elements
Staff Publications

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
10_1128_AEM_70_6_3500-3505_2004.pdf202.84 kBAdobe PDF

OPEN

NoneView/Download

SCOPUSTM   
Citations

118
checked on Oct 27, 2021

Page view(s)

82
checked on Oct 28, 2021

Google ScholarTM

Check

Altmetric


This item is licensed under a Creative Commons License Creative Commons