DNA-encoded Bimetallic Au-Pt Dumbbell Nanozyme for High-performance Detection and Eradication of Escherichia coli O157:H7

The efficacy of cetylpyridinium chloride (CPC) immersion to reduce the numbers of three pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7) on three different fresh-cut vegetables (broccoli, cauliflower, and radishes) was studied. The fresh-cut vegetables were inoculated with one of the three pathogenic bacteria at a concentration of 105 CFU/ml for 1 h at room temperature and then treated with 0.1 or 0.5% CPC immersion for 1 min. Both Salmonella Typhimurium and E. coli O157:H7 plates were incubated from 48 to 72 h at 37°C, and L. monocytogenes plates were incubated from 72 to 96 h before being counted. The results of three experiments showed that for the average of the three vegetables treated with 0.1 and 0.5% CPC, L. monocytogenes was reduced by 2.85 and 3.70 log CFU/g, Salmonella Typhimurium by 2.37 and 3.15 log CFU/g, and E. coli O157:H7 by 1.01 and 1.56 log CFU/g, respectively, in comparison with the vegetables treated with water only. The 0.5% CPC treatment was significantly different (P < 0.05) from the 0.1% CPC treatment on reduction of L. monocytogenes, Salmonella Typhimurium, and E. coli O157:H7. The CPC residual on the treated vegetables and their washing solutions were evaluated by using high-performance liquid chromatography.

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Increase in Activity of Essential Oil Components Carvacrol and Thymol against Escherichia coli O157:H7 by Addition of Food Stabilizers

Journal of Food Protection ◽

10.4315/0362-028x-68.5.919 ◽

2005 ◽

Vol 68 (5) ◽

pp. 919-926 ◽

Cited By ~ 124

Author(s):

SARA A. BURT ◽

RENÉ VLIELANDER ◽

HENK P. HAAGSMAN ◽

EDWIN J. A. VELDHUIZEN

Keyword(s):

Escherichia Coli ◽

High Performance ◽

Phage Type ◽

Density Measurement ◽

Growth Curves ◽

Ethanol Solution ◽

Escherichia Coli O157 ◽

E Coli ◽

Bactericidal Properties ◽

Liquid Chromatographic

The major components of oregano and thyme essential oils that had previously been shown to inhibit Escherichia coli O157:H7 were determined by high-performance liquid chromatography with UV detection and liquid chromatographic tandem mass spectrometry. The MICs and MBCs of carvacrol, thymol, p-cymene, and γ-terpinene against a strain of E. coli O157: H7 phage type 34 isolated from bovine feces were determined by microdilution assay. The constituents were then tested in checkerboard assays to detect possible interactions. Carvacrol and thymol displayed bacteriostatic and bactericidal properties with MICs of 1.2 mmol/liter and were additive in combination. p-Cymene and γ-terpinene displayed no measurable antibacterial activity up to 50 mmol/liter, and neither influenced the activity of carvacrol or thymol. Growth curves in the presence of nonlethal concentrations of carvacrol with the addition of agar (0.05%, wt/vol) or carrageenan (0.125%, wt/vol) as stabilizer were produced by optical density measurement. The stabilizers agar and carrageenan both significantly improved the effectiveness of carvacrol in broth, possibly because of a delay in the separation of the hydrophobic substrate from the aqueous phase of the medium. When carvacrol was dissolved in ethanol before addition to broth, stabilizers were not needed. Carvacrol and thymol, particularly when used in combination with a stabilizer or in an ethanol solution, may be effective in reducing the number or preventing growth of E. coli O157:H7 in liquid foods.

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Bedeutung von Escherichia coli O157 beim Schlachtschaf in der Schweiz

Schweizer Archiv für Tierheilkunde ◽

10.1024/0036-7281.148.6.289 ◽

2006 ◽

Vol 148 (6) ◽

pp. 289-295 ◽

Cited By ~ 8

Author(s):

C. Zweifel ◽

M. Kaufmann ◽

J. Blanco ◽

R. Stephan

Keyword(s):

Escherichia Coli ◽

Escherichia Coli O157

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

BULGARIAN JOURNAL OF VETERINARY MEDICINE ◽

10.15547/bjvm.2263 ◽

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.

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