scholarly journals The Antimicrobial Susceptibility and Detection of Virulence Genes of Escherichia coli O157:H7 Isolated from Leafy Green Vegetables

2021 ◽  
Vol 2 (3) ◽  
pp. 70-74
Author(s):  
S. E. Haramain ◽  
S. O. Yagoub
Keyword(s):  
Virulence Genes ◽  
Leafy Vegetables ◽  
Escherichia Coli O157 ◽  
Gastrointestinal Mucosa ◽  
Green Leafy Vegetable ◽  
E Coli ◽  
Green Leafy Vegetables ◽  
Negative Results ◽  
Causative Factors ◽  
Different Types

Vegetables can be vehicles for transmission of E. coli O157:H7 to humans, therefore, this study carried out in order to investigate the presence of Enterohemorrhagic E. coli in ten different types of leafy green vegetables, determined their susceptibility to thirteen antibiotics and detected the presence of some virulence genes. Method: Five-hundred samples of green leafy vegetables namely (Lettuce, Spanish, Rocket, Parsley, Mallow, Coriander, Portulaca, Lettuce, Dill, Basil and Chard) were examined for presence of E. coli O157:H7, by using standard microbiological tests (CHROMagarTM O157:H7), further detection of E. coli O157:H7 was done by Multiplex PCR (mPCR) for the detection of virulence genes (stx1, stx2, intmin and hlyA) These genes are causative factors of settlement, adhesion, and attack of STEC bacteria to gastrointestinal mucosa. Results: E. coli O157:H7 was isolated from eight (80%) out of ten types of green leafy vegetable as 12 (2.40%) in which the highest percentage of isolation was shown in Dill and Chards samples as (4.2%), Coriander and Mallow showed percentage of isolation as (3.33% and 3.03%) respectively, Parsley, Portulaca and Lettuce showed percentages of isolation as 2.43%, 1.92%, respectively, the least percentage of isolation was shown in Rocket (1.7%), No E. coli O157:H7, was detected in Spinach and Basil. Makkah collected samples showed isolation of 7 isolates out of 12 (58.33%). All isolates were resistant to Methicillin (5µg), Metronidazole (5 µg) and Ampicillin (10 µg). Stx2 (110 bp), Stx1 (349 bp), hly A (165 bp) genes were detected. All isolates showed negative results for presence of intimin gene (890 bp). This study concluded that there is a high risk for occurrence of E. coli O157:H7 outbreaks due to consumption of the green leafy vegetables sold in Jeddah Central Market. 

scholarly journals Escherichia coli O157:H7 SURVIVAL IN TRADITIONAL AND LOW LACTOSE YOGURT DURING FERMENTATION AND COOLING PERIODS

2017 ◽  
Vol 18 (0) ◽  
Author(s):  
Camila Sampaio Cutrim ◽  
Raphael Ferreira de Barros ◽  
Robson Maia Franco ◽  
Marco Antonio Sloboda Cortez
Keyword(s):  
Escherichia Coli ◽  
The Other ◽  
Lactose Hydrolysis ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Gas Formation ◽  
Whole Milk ◽  
Milk Contamination ◽  
Different Types ◽  
Fermentation Period

Abstract The purpose of this study was to evaluate the behavior of E. coli O157:H7 during lactose hydrolysis and fermentation of traditional and low lactose yogurt. It also aimed to verify E. coli O157:H7 survival after 12 h of storage at 4 ºC ±1 ºC. Two different types of yogurts were prepared, two with whole milk and two with pre-hydrolyzed whole milk; in both groups one yogurt was inoculated with E. coli O157:H7 and the other one was not inoculated. The survival of E. coli and pH of yogurt were determined during fermentation and after 12-h refrigeration. The results showed that E. coli O157:H7 was able to grow during the fermentation period (from 4.34 log CFU.mL-1 to 6.13 log CFU.mL-1 in traditional yogurt and 4.34 log CFU.mL-1 to 6.16 log CFU.mL-1 in low lactose yogurt). The samples with E. coli O157:H7 showed gas formation and syneresis. Thus, E. coli O157:H7 was able to survive and grow during fermentation of traditional and low lactose yogurts affecting the manufacture technology. Moreover, milk contamination by E. coli before LAB addition reduces the growth of L. bulgaricus and S. thermophilus especially when associated with reduction of lactose content.

Prevalence of shiga toxin-producing Escherichia coli O157, O26 and O111 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Benin

2020 ◽  
Vol 152 ◽  
pp. 15667-15675
Author(s):  
Chakirath Folakè Arikè Salifou ◽  
Cyrille Boko ◽  
Isidore Houaga ◽  
Raoul Agossa ◽  
Isabelle Ogbankotan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Animal Origin ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Milk Samples ◽  
Food Of Animal Origin ◽  
Cattle Faeces ◽  
Risk Assessment And Management

Objectives: The study aimed to search for E. coli O157 and non-O157 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Cotonou. Methodology and Results: One hundred and Seventy-Five (175) samples including 25 meat, 25 faeces per species and 25 milk from cattle were analysed for E. coli O157; O26 and O111 and the virulence genes were identified by PCR. The SAS software (1998) and the bilateral Z test were used to calculate and compare the identification frequencies. E. coli O157 was identified in 4% of cattle faeces, 4% of sheep faeces, and 20% of beef and, in 20% of milk samples. E. coli O26 was identified in 12% of cattle faeces and, in 8% of beef samples. E. coli O111 was identified at frequencies of 8%, and 12% in faeces of sheep and pigs, respectively. The eae gene was detected in 4% of beef, ovine meat, milk, pig faeces and in sheep faeces. stx1 was detected in 8% of milk, and in 4% of bovine and sheep faeces. The strains possessing the gene were all of E. coli O157 with the exception of one from pig faeces identified as O111. Conclusions and application of findings: The presence of these serogroups of E. coli with virulence genes poses a real food safety problem in Benin. This study findings must be taken into account for risk assessment and management related to the consumption of food of animal origin. Keywords: Benin, E. coli O157, O26, O111, faeces, meat, milk

How Does Escherichia coli O157:H7 Testing in Meat Compare with What We Are Seeing Clinically?

2000 ◽  
Vol 63 (6) ◽  
pp. 819-821 ◽  
Author(s):  
DAVID W. K. ACHESON
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Shiga Toxin ◽  
Food Supply ◽  
The United States ◽  
Escherichia Coli O157 ◽  
Current Policy ◽  
E Coli ◽  
Different Types ◽  
Uremic Syndrome

Escherichia coli O157:H7 is but one of a group of Shiga toxin-producing E. coli (STEC) that cause both intestinal disease such as bloody and nonbloody diarrhea and serious complications like hemolytic uremic syndrome (HUS). While E. coli O157: H7 is the most renowned STEC, over 200 different types of STEC have been documented in meat and animals, at least 60 of which have been linked with human disease. A number of studies have suggested that non-O157 STEC are associated with clinical disease, and non-O157 STEC are present in the food supply. Non-O157 STEC, such as O111 have caused large outbreaks and HUS in the United States and other countries. The current policy in the United States is to examine ground beef for O157:H7 only, but restricting the focus to O157 will miss other important human STEC pathogens.

Virulence Characterization and Molecular Subtyping of Typical and Atypical Escherichia coli O157:H7 and O157:H(−) Isolated from Fecal Samples and Beef Carcasses in Mexico

2015 ◽  
Vol 78 (2) ◽  
pp. 264-272 ◽  
Author(s):  
CLAUDIA NARVÁEZ-BRAVO ◽  
ALEJANDRO ECHEVERRY ◽  
MARKUS F. MILLER ◽  
ARGENIS RODAS-GONZÁLEZ ◽  
M. TODD BRASHEARS ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Immunomagnetic Separation ◽  
Latex Agglutination ◽  
Escherichia Coli O157 ◽  
High Genetic Diversity ◽  
E Coli ◽  
System A ◽  
Metabolic Genes ◽  
Beef Carcasses

The objective of the study was to characterize virulence genes and subtype Escherichia coli O157:H7 and O157:H(−) isolates obtained from a vertically integrated feedlot slaughter plant in Mexico. A total of 1,695 samples were collected from feedlots, holding pens, colon contents, hides, and carcasses. E. coli O157:H7 detection and confirmation was carried out using conventional microbiology techniques, immunomagnetic separation, latex agglutination, and the BAX system. A total of 97 E. coli O157 strains were recovered and screened for key virulence and metabolic genes using multiplex and conventional PCR. Eighty-eight (91.72%) of the strains carried stx2, eae, and ehxA genes. Ten isolates (8.25%) were atypical sorbitol-fermenting strains, and nine were negative for the flicH7 gene and lacked eae, stx1, stx2, and ehxA. One sorbitol-positive strain carried stx2, eae, tir, toxB, and iha genes but was negative for stx1 and ehxA. Pulsed-field gel electrophoresis (PFGE) analysis yielded 49 different PFGE subtypes, showing a high genetic diversity; however, the majority of the typical isolates were closely related (80 to 90% cutoff). Atypical O157 isolates were not closely related within them or to typical E. coli O157:H7 isolates. Identical PFGE subtypes were found in samples obtained from colon contents, feedlots, holding pens, and carcasses. Isolation of a sorbitol-fermenting E. coli O157 positive for a number of virulence genes is a novel finding in Mexico. These data showed that genetically similar strains of E. coli O157:H7 can be found at various stages of beef production and highlights the importance of preventing cross-contamination at the pre- and postharvest stages of processing.

Survival of Escherichia coli O157:H7 and Campylobacter jejuni in Bottled Purified Drinking Water under Different Storage Conditions

2011 ◽  
Vol 74 (2) ◽  
pp. 254-260 ◽  
Author(s):  
HAMZAH M. AL-QADIRI ◽  
XIAONAN LU ◽  
NIVIN I. AL-ALAMI ◽  
BARBARA A. RASCO
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Campylobacter Jejuni ◽  
Culture Media ◽  
False Negative ◽  
Storage Conditions ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction ◽  
Negative Results

Survival of Escherichia coli O157:H7 and Campylobacter jejuni that were separately inoculated into bottled purified drinking water was investigated during storage at 22, 4, and −18°C for 5, 7, and 2 days, respectively. Two inoculation levels were used, 1 and 10 CFU/ml (102 and 103 CFU/100 ml). In samples inoculated with 102 CFU/100 ml, C. jejuni was not detectable (>2-log reduction) after storage under the conditions specified above. E. coli O157:H7 was detected on nonselective and selective media at log reductions of 1.08 to 1.25 after storage at 22°C, 1.19 to 1.56 after storage at 4°C, and 1.54 to 1.98 after storage at −18°C. When the higher inoculation level of 103 CFU/100 ml was used, C. jejuni was able to survive at 22 and 4°C, with 2.25- and 2.17-log reductions, respectively, observed on nonselective media. At these higher inoculation levels, E. coli O157:H7 was detectable at 22, 4, and −18°C, with log reductions of 0.76, 0.97, and 1.21, respectively, achieved on nonselective media. Additionally, E. coli O157:H7 showed significant differences in culturability (P < 0.05) on the nonselective and selective culture media under the different storage conditions, with storage at −18°C for 2 days being the treatment most inhibiting. The percentage of sublethal injury of E. coli O157:H7 ranged from ~33 to 75%, indicating that microbial examination of bottled water must be done carefully, otherwise false-negative results or underestimation of bacterial numbers could pose a health risk when low levels of pathogens are present.

scholarly journals Evaluation of stx1, stx2, hlyA, and eaeA Virulence Genes in Escherichia coli O157:H7 Isolated from Meat (Beef and Mutton) in Hamedan, Iran, During 2015-2016

2020 ◽  
Vol 8 (2) ◽  
pp. 55-59
Author(s):  
Fatemeh Binandeh ◽  
Mohammadreza Pajohi-Alamoti ◽  
Pezhman Mahmoodi ◽  
Azam Ahangari
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Escherichia Coli O157 ◽  
Isolation And Identification ◽  
E Coli ◽  
Multiplex Pcr Assay ◽  
Agar Media ◽  
Cattle Meat ◽  
Meat Samples ◽  
Encoding Genes

Background and Objectives: Consuming raw or undercooked cattle meat is the most common transmission way of infection with Escherichia coli O157:H7. The present study aimed to identify virulence genes stx1, stx2, hlyA, and eaeA in E. coli isolated from meat samples (beef and mutton) in Hamedan during 2015 and 2016. Materials and Methods: For this purpose, the swabs were randomly taken from 160 meat samples including 80 beef samples and 80 mutton samples from butcher shops. Isolation and identification of E. coli cells were conducted by culturing the swab samples on MacConkey agar and Eosin methylene blue agar media. Then, the identity of the suspected E. coli O157:H7 colonies was investigated by a multiplex PCR assay and eventually, the isolates were evaluated for the presence of stx1, stx2, hlyA, eaeA virulence genes. Results: The results showed that out of 160 cultured samples on the selective media, 60 samples (37.5%) were contaminated with E. coli. O157:H7, O157, and H7 strains were identified using PCR, among which only E. coli O157:H7 possessed all four virulence factor encoding genes. Conclusion: The results of this study showed that beef could be a reservoir for E. coli O157:H7, and it may be involved in the transmission of this pathogen to humans.

scholarly journals Escherichia Coli O157:H7: Distribution, molecular characterization, antimicrobial resistance patterns and source of contamination of sheep and goat carcasses at an export Abattoir, Mojdo, Ethiopia

2019 ◽  
Author(s):  
Solomon Abreham ◽  
Akafete Teklu ◽  
Eric Cox ◽  
Tesfaye Sisay Tessema
Keyword(s):  
Escherichia Coli ◽  
Molecular Characterization ◽  
Virulence Genes ◽  
Antibiotic Sensitivity ◽  
Latex Agglutination ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Source Of Infection ◽  
Resistance Patterns

Abstract Background : Cattle have been identified as a major reservoir of E. coli O157:H7 for human infection; the ecology of the organism in sheep and goats is less understood. This study was carried out to determine prevalence, source of infection, antibiotic resistance and molecular characterization of Escherichia coli O157: H7 isolated from sheep and goat. Methods : Systematic random sampling was carried out at Modjo export abattoir, Ethiopia, from November 2012 to April 2013 to collect 408 samples from 72 sheep and 32 goats. Samples collected were skin swabs, fecal samples, intestinal mucosal swabs and the inside and outside part of carcasses as well as carcass in contacts such as workers hands, knife, hook and carcass washing water. Then, samples were processed following standard bacteriological procedures. Non-Sorbitol fermenting colonies were tested on latex agglutination test and the positives are subjected to PCR for detection of attaching and effacing genes ( eaeA) and shiga toxin producing genes ( stx1 and stx2 ). All E. coli O157:H7 isolates were checked for their susceptibility pattern towards 15 selected antibiotics. Results : E. coli O157:H7 were detected in only 20/408 samples (4.9%). Among these 20 positive samples, 70% (14/20), 25% (5/20) and 5% (1/20) were from sheep, goats and knife samples, respectively. No significant associations were found between carcasses and the assumed sources of contaminations. Of all the 20 isolates virulence genes were found in 10 (50%) of them; 3 (15%) with only the eaeA gene and 7(35%) expressing eaeA and stx2 genes. All the isolates were susceptible to Norfloxacin (NOR) (100%). Conclusions : The presence of virulence genes shows E. coli O157:H7 is a potential source of human infection in Ethiopia. Key words : Abattoir, antibiotic sensitivity, CT-SMAC, E. coli O157:H7, IMS, Latex agglutination, multiplex PCR.

scholarly journals The frequency of shiga-like toxin (stx1 and stx2) and EHEC-hlyA in food by multiplex PCR

2017 ◽  
Vol 25 (4) ◽  
pp. 317-326
Author(s):  
Cansu Onlen ◽  
Nizami Duran ◽  
Suphi Bayraktar ◽  
Emrah Ay ◽  
Burçin Ozer
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Multiplex Pcr ◽  
Foodborne Pathogens ◽  
Virulence Genes ◽  
Public Health Problem ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Food Borne ◽  
Stx1 Gene

Abstract Aim: The aim of the present study was to determine the frequency of shiga-like toxin (stx1 and stx2) and drug resistance profiles food-borne Escherichia coli O157:H7 in Hatay province, Turkey. Methods: The presence of the virulence genes (stx1, stx2, hlyA) in a total of 150 E.coli isolates were studied with multiplex PCR. Results: A total of 327 salad samples were analyzed. E. coli O157:H7 was detected in 150 (45.8 %) out of 327 analyzed samples. Of these 150 isolates, the presence of hly-A gene was detected in 32 (21.3%) E.coli isolates. A total of five (15.6%) isolates in this 32 hlyA positive isolates had stx2 gene, two (6.3%) of them had stx1 gene and one (3.1%) of the isolates was found to be positive for both stx1 and stx2 genes. It was found that all E.coli O157:H7 isolates were resistant to erythromycin. While the highest rate of antibiotic resistance was observed for ampicillin (68.8%), no antibiotic resistance against cefuroxime, ciprofloxacin and cephaperasone was identified. Conclusions: The results obtained in our province showed that E.coli strains isolated from salad samples were found to have some important virulence genes such as stx1, stx2, and hlyA. The stx2 frequency was found to be higher than stx1 frequency. Also, it was observed that there was not any significant correlation between drug resistance profiles and presence of toxin genes in E.coli O157:H7 strains. As a result, increasing frequency of STEC O157 serotype among foodborne pathogens is a growing public health problem.

A PDA-Based Solution for the Realization of Green Leafy Vegetable Water-Fertilizer System

2011 ◽  
Vol 366 ◽  
pp. 76-79
Author(s):  
Shun Kui Ke ◽  
Lei Li ◽  
Yu Bin Miao ◽  
Dan Feng Huang
Keyword(s):  
Personal Digital Assistant ◽  
Leafy Vegetable ◽  
Leafy Vegetables ◽  
Fertilizer Management ◽  
Long Distance ◽  
Green Leafy Vegetable ◽  
Green Leafy Vegetables ◽  
Whole Process ◽  
Distance Data ◽  
Fertilizer System

Water-fertilizer management is one of the most important parts in the realization of green leafy vegetables precise cultivation. This paper mainly focus on the problem of manual records are time-consuming and difficult to maintain, introduced to apply Personal Digital Assistant (PDA) into the whole process of green leafy vegetables water-fertilizer management. By the methods of real-time gaining of the site environment data, dynamical identifying the greenhouse ID and long-distance data transmission between PDA and database server water-fertilizer management in the green leafy vegetables production can be realized. The results show that the efficiency of green leafy vegetable water-fertilizer management can be improved by PDA-based solution.

scholarly journals First general outbreak of Verocytotoxin-producing Escherichia coli O157 in Denmark

2006 ◽  
Vol 11 (2) ◽  
pp. 1-2 ◽  
Author(s):  
C Jensen ◽  
S Ethelberg ◽  
A Gervelmeyer ◽  
E M Nielsen ◽  
K EP Olsen ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Case Control Study ◽  
Case Control ◽  
Escherichia Coli O157 ◽  
Surrounding Area ◽  
Outbreak Strain ◽  
E Coli ◽  
Surrounding Areas ◽  
Dna Profiles ◽  
Control Study

This report describes the first general outbreak of verocytotoxin-producing E. coli (VTEC) in Denmark. Twenty five patients, 18 children and seven adults, with culture-confirmed VTEC O157:H- infection and indistinguishable pulsed-field gel electrophoresis DNA profiles, were identified during a six month period from September 2003 to March 2004. The outbreak strain possessed the virulence genes: eae, vtx1 and vtx2c. All patients but one presented with diarrhoea; none developed haemolytic uraemic syndrome. The outbreak was restricted to Copenhagen and surrounding areas. A case-control study including 11 cases and 55 matched controls revealed an association between VTEC O157:H- infection and shopping in a specific supermarket chain in Copenhagen and surrounding area, matched odds ratio (OR): 8.7 (95% confidence interval (CI): 1.1-71). After exclusion of three assumed secondary cases, only consumption of a particular kind of organic milk from a small dairy was associated with disease OR: 8.7 (95% CI 1.6-48). Environmental and microbiological investigations at the suspected dairy did not confirm the presence of the outbreak strain, but the outbreak stopped once the dairy was closed and thoroughly cleaned.

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