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

2005 ◽  
Vol 68 (5) ◽  
pp. 919-926 ◽  
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.

Escherichia coli O157 Diversity with Respect to Survival during Drying on Concrete

2003 ◽  
Vol 66 (5) ◽  
pp. 780-786 ◽  
Author(s):  
S. M. AVERY ◽  
S. BUNCIC
Keyword(s):  
Escherichia Coli ◽  
Survival Rate ◽  
Phage Type ◽  
Survival Rates ◽  
Pfge Type ◽  
Meat Production ◽  
Escherichia Coli O157 ◽  
Production Chain ◽  
E Coli ◽  
Wide Range

Shiga toxin (Stx)–producing Escherichia coli O157 isolates (n = 123) were divided into groups according to origin, genotype (pulsed-field gel electrophoresis [PFGE] type, or ribotype), type of Stx produced, or phage type (PT). The survival rate ([number of CFU after 24 h of drying/number of CFU before drying] × 100) for each isolate was determined in triplicate after drying on concrete for 24.0 h. The overall mean survival rate among the 123 E. coli O157 isolates studied was 22.9%, but there was a wide range of responses to drying on concrete, with a minimum of 1.2% and a maximum of 61.9% of the initial inocula being recovered after drying. Among the groups, those isolates that originated from cases of human disease were, on average, significantly more sensitive (P < 0.001) to drying (with a mean survival rate of 15.3%) than isolates from the other three sources (with mean survival rates of 27.7, 26.0, and 22.9% for meats, bovine or ovine feces, and bovine hides, respectively). When the isolates were grouped by genotype, three of the PFGE types were, on average, significantly more resistant to drying than two other PFGE types were, and similarly, significant differences in average resistance to drying between groups of E. coli O157 with different ribotypes were seen. There were no differences between the abilities of isolates producing different Stxs (Stx 1 or Stx 1 and Stx 2) to survive drying. E. coli O157 isolates of PT4, PT21/28, and PT32 survived drying on concrete better than groups of other PTs did. Since the E. coli O157 isolates had various abilities to survive drying on concrete, drying could contribute to a kind of E. coli O157 natural selection along the meat chain. This possibility may have significant meat safety implications if a range of E. coli O157 isolates are simultaneously exposed to drying at any point along the meat production chain. Those E. coli O157 isolates that are more able to survive drying could be more likely to pass farther along the meat chain and ultimately reach consumers.

scholarly journals Escherichia coli O157[ratio ]H7 diarrhoea associated with well water and infected cattle on an Ontario farm

1998 ◽  
Vol 120 (1) ◽  
pp. 17-20 ◽  
Author(s):  
S. G. JACKSON ◽  
R. B. GOODBRAND ◽  
R. P. JOHNSON ◽  
V. G. ODORICO ◽  
D. ALVES ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phage Type ◽  
Dairy Farm ◽  
Female Child ◽  
Well Water ◽  
Escherichia Coli O157 ◽  
Cattle Farm ◽  
E Coli ◽  
Unpasteurized Milk ◽  
Hydrogeological Investigation

A 16-month old female child living on an Ontario dairy farm was taken to hospital suffering from bloody diarrhoea. Escherichia coli O157[ratio ]H7 was isolated from her stool. Initial tests of well water samples were negative for E. coli by standard methods but culture of selected coliform colonies on sorbitol-MacConkey agar led to isolation of E. coli O157[ratio ]H7. E. coli O157[ratio ]H7 was also isolated from 63% of cattle on the farm. The E. coli O157[ratio ]H7 isolates from the child, the water and the cattle were phage type 14, produced verotoxins 1 and 2, and were highly related on analysis by pulsed field gel electrophoresis. The child did not have known direct contact with the cattle and did not consume unpasteurized milk. Hydrogeological investigation revealed the design and location of the well would allow manure-contaminated surface water to flow into the well. This investigation demonstrates that cattle farm well water is a potential source of E. coli O157[ratio ]H7 which may not be identified by standard screening for E. coli in water.

scholarly journals An outbreak of Escherichia coli O157 phage type 2 infection in Paisley, Scotland

2007 ◽  
Vol 12 (34) ◽  
Author(s):  
A Stirling ◽  
G McCartney ◽  
S Ahmed ◽  
J Cowden
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
National Health ◽  
Phage Type ◽  
Health Protection ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Public Health Protection

The National Health Service’s (NHS) Greater Glasgow and Clyde Public Health Protection Unit is currently investigating an outbreak of E. coli O157 infection in Paisley.

Growth of Escherichia coli O157:H7 at Fluctuating Incubation Temperatures

1995 ◽  
Vol 58 (12) ◽  
pp. 1307-1313 ◽  
Author(s):  
KATHLEEN T. RAJKOWSKI ◽  
BENNE S. MARMER
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogen ◽  
Brain Heart Infusion ◽  
Growth Curves ◽  
Escherichia Coli O157 ◽  
Growth Responses ◽  
Growth Data ◽  
Fluctuating Temperature ◽  
E Coli ◽  
Fluctuating Temperatures

Temperature abuse of foods is often transitory and little information is available describing the response of the foodborne pathogen, Escherichia coli O157:H7, to nonisothermal and/or fluctuating temperature storage. Growth responses were determined for a mixture of three E. coli O157:H7 strains in brain heart infusion (BHI) broth as a function of temperature (static and fluctuating), initial pH (5, 6, and 7), and NaCl content (0.5, 1, 2, and 3%). Five 6-h “square-wave” fluctuating temperature regimes were used: 4 to 12, 4 to 19, 4 to 28, 8 to 19, and 12 to 28°C and compared with growth at 8, 10, 12, 19, and 28°C. The growth curves obtained from fitting the Gompertz equation for the fluctuating temperatures were compared to those obtained for the static temperatures. Increased NaCl concentration decreased growth temperature both for the fluctuating temperature growth curves and the static growth data. The cells grew or remained viable for up to 21 days under all conditions and fluctuating temperatures. Growth kinetics at fluctuating temperatures more closely approximated the higher temperature than the midpoint temperature of each cyclic range. The results indicate that transitory abuse could lead to more rapid growth than expected of E. coli O157:H7 in foods and that given sufficient time E. coli O157:H7 can grow at as low as 8°C.

Efficacy of Cetylpyridinium Chloride in Immersion Treatment for Reducing Populations of Pathogenic Bacteria on Fresh-Cut Vegetables

2001 ◽  
Vol 64 (12) ◽  
pp. 2071-2074 ◽  
Author(s):  
HONG WANG ◽  
YANBIN LI ◽  
MICHAEL F. SLAVIK
Keyword(s):  
Escherichia Coli ◽  
High Performance Liquid Chromatography ◽  
Salmonella Typhimurium ◽  
High Performance ◽  
Pathogenic Bacteria ◽  
Room Temperature ◽  
Cetylpyridinium Chloride ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Fresh Cut

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.

scholarly journals Large E. coli O157 outbreak in Ireland, October-November 2005

2005 ◽  
Vol 10 (51) ◽  
Author(s):  
Collective Multi-agency Outbreak Control Team
Keyword(s):  
Escherichia Coli ◽  
Rural Area ◽  
Phage Type ◽  
Escherichia Coli O157 ◽  
E Coli

Between 15 October and 30 November 2005, 18 cases of Escherichia coli O157, phage type 32, verotoxin 2 positive were identified in a small rural area of midwest Ireland.

scholarly journals Analysis of Feces Samples Collected from a Wild-Bird Garden Feeding Station in Scotland for the Presence of Verocytotoxin-Producing Escherichia coli O157

2006 ◽  
Vol 72 (3) ◽  
pp. 2265-2267 ◽  
Author(s):  
Geoffrey Foster ◽  
Judith Evans ◽  
Hazel I. Knight ◽  
Alastair W. Smith ◽  
George J. Gunn ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wild Bird ◽  
Phage Type ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Feeding Station ◽  
Bird Feces

ABSTRACT Composite wild bird feces collected at regular intervals from a garden feeding station in southwest Scotland over a 3-year period were examined for verocytotoxin-producing Escherichia coli O157. One sample was positive for Escherichia coli O157. The isolate belonged to phage type 21/28 and possessed vtx 2, eaeA, and enterohemorrhagic E. coli hlyA genes.

Characterization of bacteriophages with a lytic effect on various Salmonella serotypes and Escherichia coli O157:H7

2011 ◽  
Vol 57 (12) ◽  
pp. 1042-1051 ◽  
Author(s):  
Osvaldo López-Cuevas ◽  
Nohelia Castro-del Campo ◽  
Josefina León-Félix ◽  
Arturo González-Robles ◽  
Cristóbal Chaidez
Keyword(s):  
Escherichia Coli ◽  
Burst Size ◽  
Growth Curves ◽  
Escherichia Coli O157 ◽  
Genetic Characteristics ◽  
E Coli ◽  
Lytic Effect ◽  
One Step ◽  
Salmonella Serotypes

Four phages isolated from cattle and poultry feces were analyzed for their ability to lyse Salmonella serotypes and Escherichia coli O157:H7. The phage one-step growth curves, morphology, and genetic characteristics were determined. All phages showed a lytic effect on various Salmonella serotypes and E. coli O157:H7, which lysed at least 70% of the 234 strains tested. The phages had latent periods ranging from 10 to 15 min and generation times of 30 to 45 min, while burst size fluctuated between 154 and 426 PFU/cell. Phages morphology showed isometric and elongated heads and rigid contractile tails, consistent with morphology of the Myoviridae family. Phages’ DNA dendrograms showed a distinctive RFLP when digested by HindIII and EcoRV, and SDS–PAGE profile showed distinctive proteins expression as well. In vitro phage challenge showed a total reduction of E. coli O157:H7, Salmonella Typhimurium and Saintpaul counts at 2 h, whereas for Salmonella Montevideo a reduction and retardation growth, at a multiplicity of infection (MOI) of 100, was observed; however, under a MOI of 10 000, no viable cells were detected after 4 h. The wide host ranges of these phages suggested they could be used for simultaneous biocontrol of some Salmonella serotypes and E. coli O157:H7.

Antimicrobial Effects of Zataria multiflora and Ocimum basilicum on Escherichia coli O157:H7 During Ripening of Traditional Lighvan Cheese

2020 ◽  
Vol 16 (3) ◽  
pp. 373-380
Author(s):  
Mohammad B. Zendeh ◽  
Vadood Razavilar ◽  
Hamid Mirzaei ◽  
Khosrow Mohammadi
Keyword(s):  
Escherichia Coli ◽  
Essential Oils ◽  
Dairy Products ◽  
Antimicrobial Agents ◽  
Escherichia Coli O157 ◽  
Zataria Multiflora ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Common Causes ◽  
Lighvan Cheese

Background: Escherichia coli O157:H7 is one of the most common causes of contamination in Lighvan cheese processing. Using from natural antimicrobial essential oils is applied method to decrease the rate of microbial contamination of dairy products. The present investigation was done to study the antimicrobial effects of Z. multiflora and O. basilicum essential oils on survival of E. coli O157:H7 during ripening of traditional Lighvan cheese. Methods: Leaves of the Z. multiflora and O. basilicum plants were subjected to the Clevenger apparatus. Concentrations of 0, 100 and 200 ppm of the Z. multiflora and 0, 50 and 100 ppm of O. basilicum essential oils and also 103 and 105 cfu/ml numbers of E. coli O157:H7 were used. The numbers of the E. coli O157:H7 bacteria were analyzed during the days 0, 30, 60 and 90 of the ripening period. Results: Z. multiflora and O. basilicum essential oils had considerable antimicrobial effects against E. coli O157:H7. Using the essential oils caused decrease in the numbers of E. coli O157:H7 bacteria in 90th days of ripening (P <0.05). Using from Z. multiflora at concentration of 200 ppm can reduce the survival of E. coli O157:H7 in Lighvan cheese. Conclusion: Using Z. multiflora and O. basilicum essential oils as good antimicrobial agents can reduce the risk of foodborne bacteria and especially E. coli O157:H7 in food products.

Biodecomposition of Phenanthrene and Pyrene by a Genetically Engineered Escherichia coli

2020 ◽  
Vol 14 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Maryam Ahankoub ◽  
Gashtasb Mardani ◽  
Payam Ghasemi-Dehkordi ◽  
Ameneh Mehri-Ghahfarrokhi ◽  
Abbas Doosti ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Performance ◽  
Human Cancer ◽  
Genetically Engineered ◽  
Hazardous Substances ◽  
E Coli ◽  
Spiked Soil ◽  
Engineered Escherichia Coli ◽  
Genetically Manipulated ◽  
Hplc Measurement

Background: Genetically engineered microorganisms (GEMs) can be used for bioremediation of the biological pollutants into nonhazardous or less-hazardous substances, at lower cost. Polycyclic aromatic hydrocarbons (PAHs) are one of these contaminants that associated with a risk of human cancer development. Genetically engineered E. coli that encoded catechol 2,3- dioxygenase (C230) was created and investigated its ability to biodecomposition of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC) measurement. We revised patents documents relating to the use of GEMs for bioremediation. This approach have already been done in others studies although using other genes codifying for same catechol degradation approach. Objective: In this study, we investigated biodecomposition of phenanthrene and pyrene by a genetically engineered Escherichia coli. Methods: Briefly, following the cloning of C230 gene (nahH) into pUC18 vector and transformation into E. coli Top10F, the complementary tests, including catalase, oxidase and PCR were used as on isolated bacteria from spiked soil. Results: The results of HPLC measurement showed that in spiked soil containing engineered E. coli, biodegradation of phenanthrene and pyrene comparing to autoclaved soil that inoculated by wild type of E. coli and normal soil group with natural microbial flora, were statistically significant (p<0.05). Moreover, catalase test was positive while the oxidase tests were negative. Conclusion: These findings indicated that genetically manipulated E. coli can provide an effective clean-up process on PAH compounds and it is useful for bioremediation of environmental pollution with petrochemical products.

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