scholarly journals Escherichia coli O157:H7 Acid Sensitivity Correlates with Flocculation Phenotype during Nutrient Limitation

2017 ◽  
Vol 8 ◽  
Author(s):  
Kathryn L. Kay ◽  
Frederick Breidt ◽  
Pina M. Fratamico ◽  
Gian M. Baranzoni ◽  
Gwang-Hee Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nutrient Limitation ◽  
Escherichia Coli O157 ◽  
Acid Sensitivity

Molecular profiling and antimicrobial susceptibility of Escherichia coli O157:H7 isolated in Bulgaria

2020 ◽  
Vol 23 (3) ◽  
pp. 310-318
Author(s):  
K. Koev ◽  
T. Stoyanchev ◽  
G. Zhelev ◽  
P. Marutsov ◽  
K. Gospodinova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Acid Sensitivity ◽  
Lower Extent ◽  
Phenotype Analysis ◽  
Anal Swab ◽  
Amoxicillin Clavulanic Acid ◽  
Primary Identification ◽  
Stx1 Gene ◽  
Cattle Farms

The purpose of this study was to detect the presence of shiga-toxin producing Escherichia coli (STEC) in faeces of healthy dairy cattle and to determine the sensitivity of isolates to several anti­microbial drugs. A total of 1,104 anal swab samples originating from 28 cattle farms were examined. After the primary identification, 30 strains were found to belong to serogroup О157. By means of conventional multiplex PCR, isolates were screened for presence of resistance genes stx1, stx2 and eaeА. Twenty-nine strains possesses amplicons with a size corresponding to genes stx2 and eaeA, one had amplicons also for the stx1 gene and one lacked amplicons of all three genes. Twenty-eight strains demonstrated amplicons equivalent to gene H7. The results from phenotype analysis of resistance showed preserved sensitivity to ceftriaxone, ceftazidime, cefotaxime, cephalothin, streptomycin, gentamicin, tetracycline, enrofloxacin and combinations sulfamethoxazole/trimethoprim and amoxicillin/clavulanic acid. Sensitivity to ampicillin was relatively preserved, although at a lower extent.

Role of Nutrient Limitation in the Competition between Pseudomonas fluorescens and Escherichia coli O157:H7

2007 ◽  
Vol 70 (7) ◽  
pp. 1739-1743 ◽  
Author(s):  
R. C. MCKELLAR
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Fluorescens ◽  
Nutrient Limitation ◽  
Foodborne Pathogens ◽  
Raw Milk ◽  
Inhibitory Effect ◽  
Nutrient Broth ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Spoilage Microflora

Competition between spoilage microorganisms and foodborne pathogens provides a potentially simple approach to limiting the growth of pathogens. A strain of Pseudomonas fluorescens isolated from raw milk repressed growth of Escherichia coli O157:H7 at 22°C in nutrient broth once the maximum population density of the pseudomonad had been reached (9.6 log CFU ml−1). The presence of iron in the growth medium and the parallel inhibitory effect of a siderophore-deficient mutant of P. fluorescens precluded iron limitation as the mechanism of action. Medium depleted by prior growth of P. fluorescens prevented the growth of E. coli, and this effect was reversed by the replenishment of the nutrient broth, its component fractions, or the addition of soy peptones but not peptones derived from milk protein. This is the first report of competition between spoilage microflora and foodborne pathogens in which the mechanism was clearly shown to be nutrient limitation. These results suggest possible improvements in biocontrol systems to prevent pathogen growth on foods.

scholarly journals Enhanced Acid Sensitivity of Pressure-Damaged Escherichia coli O157 Cells

2001 ◽  
Vol 67 (4) ◽  
pp. 1983-1985 ◽  
Author(s):  
Rafael Pagán ◽  
Sarah Jordan ◽  
Amparo Benito ◽  
Bernard Mackey
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Cytoplasmic Ph ◽  
Ph Homeostasis ◽  
Acid Sensitivity ◽  
Acid Labile

ABSTRACT Pressure-damaged Escherichia coli O157 cells were more acid sensitive than native cells and were impaired in pH homeostasis. However differences in acid sensitivity were not related to differences in cytoplasmic pH (pHi). Cellular β-galactosidase was more acid labile in damaged cells. Sensitization to acid may thus involve loss of protective or repair functions.

Bedeutung von Escherichia coli O157 beim Schlachtschaf in der Schweiz

2006 ◽  
Vol 148 (6) ◽  
pp. 289-295 ◽  
Author(s):  
C. Zweifel ◽  
M. Kaufmann ◽  
J. Blanco ◽  
R. Stephan
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157

Crystal Structure of Murein-Tripeptide Amidase MpaA from Escherichia coli O157 at 2.6 Å Resolution

2017 ◽  
Vol 24 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Yinliang Ma ◽  
Guohui Bai ◽  
Yaqi Cui ◽  
Jing Zhao ◽  
Zenglin Yuan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Escherichia Coli O157
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