Development of Digoxigenin-Labeled PCR Amplicon Probes for Use in the Detection and Identification of Enteropathogenic Yersinia and Shiga Toxin–Producing Escherichia coli from Foods

1999 ◽  
Vol 62 (5) ◽  
pp. 438-443 ◽  
Author(s):  
STEPHEN D. WEAGANT ◽  
JAMES A. JAGOW ◽  
KAREN C. JINNEMAN ◽  
CURTIS J. OMIECINSKI ◽  
CHARLES A. KAYSNER ◽  
...  

By including digoxigenin-11-dUTP in a polymerase chain reaction (PCR), amplification products were produced that contained nonisotopic markers for use as DNA hybridization probes. Because these labeled amplicons encode pathogenic traits for specific foodborne bacteria, they can be used to detect the presence of potentially virulent organisms that may be present in foods. This technology allows the synthesis of a variety of shelf-stable probe reagents for detecting a number of foodborne microbes of public health concern. We used this technology to detect four genes in two potential pathogens: virF and yadA in enteropathogenic Yersinia and stx1 and stx2 in Shiga-like toxin–producing Escherichia coli. Results of DNA hybridizations of dot blots of 68 Yersinia strains and 24 of 25 E. coli strains were consistent with results of equivalent PCR analyses. DNA colony hybridization with nonisotopic virF probes of colonies arising on spread plates from artificially contaminated food homogenates was able to detect potentially pathogenic Y. enterocolitica. When compared with oligonucleotide probes, amplicon probes are much less sensitive to changes in hybridization and wash temperatures, allowing greater reproducibility. Labeled probe preparations were reused more than five times and have been stored at −20°C for more than 8 months. This method conveniently generates probes that are safe, stable, inexpensive, reusable, and reliable.

1994 ◽  
Vol 57 (9) ◽  
pp. 780-783 ◽  
Author(s):  
TONG ZHAO ◽  
MICHAEL P. DOYLE

The fate of enterohemorrhagic Escherichia coli O157:H7 was determined in three different lots of commercial mayonnaise, including four different samples from a lot implicated in an outbreak of E. coli O157:H7 infection. The initial pH of the products ranged from 3.6 to 3.9. Products were inoculated with 6.5 × 103 E. coli O157:H7/g and incubated at 5 or 20°C. Escherichia coli O157:H7 did not grow at either temperature but survived for 34 to 55 days at 5°C and for 8 to 21 days at 20°C, depending on the lot. Survival was greatest in real mayonnaise purchased at retail among six mayonnaise samples which included a reduced calorie mayonnaise. Escherichia coli O157:H7 populations decreased between 2- and 100-fold by 3 weeks at 5°C, and between 10- and 1,000-fold by 7 days at 20°C. There was little or no change in pH (<0.1 unit), aerobic plate count, mold and yeast count or Lactobacillus count (< 1 log10 CFU/g) for the duration of the study. Commercial mayonnaise manufactured under good manufacturing practices is not a public health concern. Abusive handling of mayonnaise resulting in cross-contamination with E. coli O157:H7-contaminated food or contamination by an infected foodhandler is the principal basis for concern.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Pouya Reshadi ◽  
Fatemeh Heydari ◽  
Reza Ghanbarpour ◽  
Mahboube Bagheri ◽  
Maziar Jajarmi ◽  
...  

Abstract Background Transmission of antimicrobial resistant and virulent Escherichia coli (E. coli) from animal to human has been considered as a public health concern. This study aimed to determine the phylogenetic background and prevalence of diarrheagenic E. coli and antimicrobial resistance in healthy riding-horses in Iran. In this research, the genes related to six main pathotypes of E. coli were screened. Also, genotypic and phenotypic antimicrobial resistance against commonly used antibiotics were studied, then phylo-grouping was performed on all the isolates. Results Out of 65 analyzed isolates, 29.23 % (n = 19) were determined as STEC and 6.15 % (n = 4) as potential EPEC. The most prevalent antimicrobial resistance phenotypes were against amoxicillin/clavulanic acid (46.2 %) and ceftriaxone (38.5 %). blaTEM was the most detected resistance gene (98.4 %) among the isolates and 26.15 % of the E. coli isolates were determined as multi-drug resistant (MDR). Three phylo-types including B1 (76.92 %), A (13.85 %) and D (3.08 %) were detected among the isolates. Conclusions Due to the close interaction of horses and humans, these findings would place emphasis on the pathogenic and zoonotic potential of the equine strains and may help to design antimicrobial resistance stewardship programs to control the dissemination of virulent and multi-drug resistant E. coli strains in the community.


2019 ◽  
Author(s):  
Elizabeth Muligisa Muonga ◽  
Geoffrey Mainda ◽  
Mercy Mukuma ◽  
Geoffrey Kwenda ◽  
Bernard Hang'ombe ◽  
...  

Abstract Background Antimicrobial resistance (AMR) of foodborne pathogens is of public health concern, especially in developing countries like Zambia. This study was undertaken to determine the resistance profiles of Escherichia coli ( E. coli ) and Salmonella isolated from dressed broiler chickens purchased from open markets and supermarkets in Zambia.Results A total of 189 E. coli and five Salmonella isolates were isolated. Identification and confirmation of the isolates was done using Analytical Profile Index (API 20E) (Biomerieux ® ) and 16S rRNA sequencing. Antimicrobial susceptibility tests (AST) were performed using the Kirby Bauer disk diffusion technique using a panel of 10 different antibiotics and multiplex PCR was used to determine the presence of three target genes encoding for resistance: tetA, Sul1 and CTXM. AST results were entered and analyzed in WHONET 2018 software. A total of 189 E. coli and five Salmonella isolates were identified. Among the E. coli isolates, Tetracycline recorded the highest resistance of 79.4%, followed by Ampicillin 51.9%, Trimethoprim/Sulfamethoxazole 49.7%, Nalidixic Acid 24.3%, Chloramphenicol 16.4%, Cefotaxime 16.4%, Ciprofloxacin 10.1%, Colistin 7.4%, Amoxicillin/Clavulanic acid 6.9%, and Imipenem 1.1%. Two of the five Salmonella isolates were resistant to at least one antibiotic. Forty- seven (45.2%) of the isolates possessed at least one of the targeted resistance genes.Conclusion This study has demonstrated the presence of AMR E. coli and Salmonella on raw broiler chickens from both open markets and supermarkets. Such resistance is of public health concern and measures need to be put in place to regulate the use of these antimicrobials in poultry production.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Neha Giri ◽  
Anchal Lodhi ◽  
Devendra Singh Bisht ◽  
Suvarna Bhoj ◽  
Deepak Kumar Arya

Researchers have encountered new challenges with the discovery of multiple drug resistance in microbes. Currently, multidrug resistant bacteria are considered a major public health concern and an emerging global epidemic. Presence of Escherichia coli in water is used as a faecal pollution measure. In this study E. coli isolates were collected from 20 sample collection sites at Lake Nainital. 20 E. coli isolates, 1 from each sample collection sites, were examined for their antibiotic response patterns against a panel of widely used 15 antibiotics. The result of this study showed 100% resistance to Penicillin G followed by Erythromycin (80%). All isolates (100%) were found susceptible for Gentamycin. The susceptibilities for Chloramphenicol and Co-trimoxazaole were found next to Gentamycin as 90 and 85% respectively. Multiple antibiotic resistance (MAR) index was also determined. 0.73 MAR index was observed as highest in 1 isolate. 13 out of 20 isolates had more than 0.2 MAR indices. The result reveals the origin of E. coli isolates from an area of high antibiotics use.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 396 ◽  
Author(s):  
Michaela Sannettha van den Honert ◽  
Pieter Andries Gouws ◽  
Louwrens Christiaan Hoffman

Studies have shown that antibiotic resistance among wild animals is becoming a public health concern, owing to increased contact and co-habitation with domestic animals that, in turn, results in increased human contact, indirectly and directly. This type of farming practice intensifies the likelihood of antibiotic resistant traits in microorganisms transferring between ecosystems which are linked via various transfer vectors, such as rivers and birds. This study aimed to determine whether the practice of wildlife supplementary feeding could have an influence on the antibiotic resistance of the bacteria harboured by the supplementary fed wildlife, and thus play a potential role in the dissemination of antibiotic resistance throughout nature. Escherichia coli and Enterococcus were isolated from the faeces of various wildlife species from seven different farms across South Africa. The Kirby-Bauer disk diffusion method was used according to the Clinical and Laboratory Standards Institute 2018 guidelines. The E. coli (F: 57%; N = 75% susceptible) and Enterococcus (F: 67%; N = 78% susceptible) isolates from the supplementary fed (F) wildlife were in general, found to be more frequently resistant to the selection of antibiotics than from those which were not supplementary fed (N), particularly towards tetracycline (E. coli F: 56%; N: 71%/Enterococcus F: 53%; N: 89% susceptible), ampicillin (F: 82%; N = 95% susceptible) and sulphafurazole (F: 68%; N = 98% susceptible). Interestingly, high resistance towards streptomycin was observed in the bacteria from both the supplementary fed (7% susceptible) and non-supplementary fed (6% susceptible) wildlife isolates. No resistance was found towards chloramphenicol and ceftazidime.


2019 ◽  
Vol 18 (1) ◽  
pp. 67-76 ◽  
Author(s):  
David Ortega-Paredes ◽  
Pedro Barba ◽  
Santiago Mena-López ◽  
Nathaly Espinel ◽  
Verónica Crespo ◽  
...  

Abstract Urban river pollution by multidrug-resistant (MDR) bacteria constitutes an important public health concern. Epidemiologically important strains of MDR Escherichia coli transmissible at the human–animal–environment interfaces are especially worrying. Quantifying and characterizing MDR E. coli at a molecular level is thus imperative for understanding its epidemiology in natural environments and its role in the spread of resistance in precise geographical areas. Cefotaxime-resistant E. coli was characterized along the watercourse of the major urban river in Quito. Our results showed high quantities of cefotaxime-resistant E. coli (2.7 × 103–5.4 × 105 CFU/100 mL). The antimicrobial resistance index (ARI) revealed the exposure of the river to antibiotic contamination, and the multiple antibiotic resistance index indicated a high risk of contamination. The blaCTX-M-15 gene was the most prevalent in our samples. Isolates also had class 1 integrons carrying aminoglycoside-modifying enzymes and folate pathway inhibitors. The isolates belonged to phylogroups A, B1 and D. Clonal complex 10 was found to be the most prevalent (ST10, ST44 and ST 167), followed by ST162, ST394 and ST46. Our study provides a warning about the high potential of the major urban river in Quito for spreading the epidemiologically important MDR E. coli.


2015 ◽  
Vol 59 (9) ◽  
pp. 5171-5180 ◽  
Author(s):  
M. A. Fleury ◽  
G. Mourand ◽  
E. Jouy ◽  
F. Touzain ◽  
L. Le Devendec ◽  
...  

ABSTRACTResistance to extended-spectrum cephalosporins (ESCs) is an important health concern. Here, we studied the impact of the administration of a long-acting form of ceftiofur on the pig gut microbiota and ESC resistance inEscherichia coli. Pigs were orally inoculated with an ESC-resistantE. coliM63 strain harboring a conjugative plasmid carrying a gene conferring resistance,blaCTX-M-1. On the same day, they were given or not a unique injection of ceftiofur. Fecal microbiota were studied using quantitative PCR analysis of the main bacterial groups and quantification of short-chain fatty acids.E. coliand ESC-resistantE. coliwere determined by culture methods, and the ESC-resistantE. coliisolates were characterized. The copies of theblaCTX-M-1gene were quantified. After ceftiofur injection, the main change in gut microbiota was the significant but transitory decrease in theE. colipopulation. Acetate and butyrate levels were significantly lower in the treated group. In all inoculated groups,E. coliM63 persisted in most pigs, and theblaCTX-M-1gene was transferred to otherE. coli. Culture and PCR results showed that the ceftiofur-treated group shed significantly more resistant strains 1 and 3 days after ESC injection. Thereafter, on most dates, there were no differences between the groups, but notably, one pig in the nontreated group regularly excreted very high numbers of ESC-resistantE. coli, probably leading to a higher contamination level in its pen. In conclusion, the use of ESCs, and also the presence of high-shedding animals, are important features in the spread of ESC resistance.


1998 ◽  
Vol 64 (11) ◽  
pp. 4134-4141 ◽  
Author(s):  
Carlton Gyles ◽  
Roger Johnson ◽  
Anli Gao ◽  
Kim Ziebell ◽  
Denis Pierard ◽  
...  

ABSTRACT In this study we investigated whether the enterohemorrhagicEscherichia coli (EHEC) hemolysin gene ehxAcould be used as an indicator of pathogenicity in Shiga-like-toxin-producing Escherichia coli (SLTEC) isolates. The isolates in a collection of 770 SLTEC strains of human and bovine origins were assigned to group 1 (230 human and 138 bovine SLTEC isolates belonging to serotypes frequently implicated in human disease), group 2 (85 human and 183 bovine isolates belonging to serotypes less frequently implicated in disease), and group 3 (134 bovine isolates belonging to serotypes not implicated in disease). PCR amplification was used to examine all of the SLTEC isolates for the presence of ehxA and the virulence-associated geneseae, slt-I, and slt-II. The percentages of human isolates in groups 1 and 2 that were positive forehxA were 89 and 46%, respectively, and the percentages of bovine isolates in groups 1 to 3 that were positive forehxA were 89, 51, and 52%, respectively. The percentages of human isolates in groups 1 and 2 that were positive foreae were 92 and 27%, respectively, and the percentages of bovine isolates in groups 1 to 3 that were positive for eaewere 78, 15, and 19%, respectively. The frequencies of bothehxA and eae were significantly higher for group 1 isolates than for group 2 isolates. The presence of the ehxA gene was associated with serotype, as was the presence of the eae gene. Some serotypes, such as O117:H4, lacked both eae and ehxA and have been associated with severe disease, but only infrequently. Theslt-I genes were more frequent in group 1 isolates than in group 2 isolates, and the slt-II genes were more frequent in group 2 isolates than in group 1 isolates. In a second experiment we determined the occurrence of the ehxA andslt genes in E. coli isolated from bovine feces. Fecal samples from 175 animals were streaked onto washed sheep erythrocyte agar plates. Eight E. coli-like colonies representing all of the morphological types were transferred to MacConkey agar. A total of 1,080 E. coli isolates were examined, and the ehxA gene was detected in 12 independent strains, only 3 of which were positive for slt. We concluded that the ehxA gene was less correlated with virulence than the eae gene was and that EHEC hemolysin alone has limited value for screening bovine feces for pathogenic SLTEC because of presence of the ehxA gene in bovine isolates that are not SLTEC.


2017 ◽  
Vol 81 (2) ◽  
pp. 302-307 ◽  
Author(s):  
Nahla O. Eltai ◽  
Elmoubasher A. Abdfarag ◽  
Hamad Al-Romaihi ◽  
Eman Wehedy ◽  
Mahmoud H. Mahmoud ◽  
...  

ABSTRACT Antibiotic resistance (AR) is a growing public health concern worldwide, and it is a top health challenge in the 21st century. AR among Enterobacteriaceae is rapidly increasing, especially in third-generation cephalosporins and carbapenems. Further, strains carrying mobilized colistin resistance (mcr) genes 1 and 2 have been isolated from humans, food-producing animals, and the environment. The uncontrolled use of antibiotics in food-producing animals is a major factor in the generation and spread of AR. No studies have been done to evaluate AR in the veterinary sector of Qatar. This study aimed at establishing primary baseline data for the prevalence of AR among food-producing animals in Qatar. Fecal samples (172) were obtained from two broiler farms and one live bird market in Qatar, and 90 commensal Escherichia coli bacteria were isolated and subjected to susceptibility testing against 16 clinically relevant antibiotics by using the E-test method. The results found that 81 (90%) of 90 isolates were resistant to at least one antibiotic, 14 (15.5%) of 90 isolates were colistin resistant, 2 (2.2%) of 90 isolates were extended-spectrum β-lactamase producers, and 2 (2.2%) of 90 isolates were multidrug resistant to four antibiotic classes. Extended-spectrum β-lactamase–producing E. coli and colistin-resistant isolates were confirmed by using double-disc susceptibility testing and PCR, respectively. Such a high prevalence of antibiotic-resistant E. coli could be the result of a long application of antibiotic treatment, and it is an indicator of the antibiotic load in food-producing animals in Qatar. Pathogens carrying AR can be easily transmitted to humans through consumption of undercooked food or noncompliance with hygiene practices, mandating prompt development and implementation of a stewardship program to control and monitor the use of antibiotics in the community and agriculture.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Mourouge Saadi Alwash ◽  
Hawraa Mohammed Al-Rafyai

Surface water contamination remains a major worldwide public health concern and may contribute to the dissemination of antibiotic-resistant bacteria. The Al-Hillah River in the city of Babylon Province, Iraq, diverts flows from the Euphrates River. Because of its importance in irrigation and population density, it faces several forced and unforced changes due to anthropogenic activities. To evaluate water quality, water samples were collected from three sites with different anthropogenic pressures along the Al-Hillah River. These samples were subjected to bacteriological analyses, i.e., total coliforms, Escherichia coli, and faecal enterococci. The phylogenetic groups of the E. coli isolates (n = 61) were typed by rapid PCR-based analyses. Representatives of each isolate were tested phenotypically for resistance to six classes of antibiotics and characterized according to their phylogenetic groups. The results demonstrated the highest resistance levels were to β-lactam antibiotics, followed by fosfomycin and aminoglycosides. Escherichia coli isolates belonging to phylogenetic groups A and B2 were the most common and were characterized by a higher prevalence of antibiotic resistance. This study is important for understanding the current conditions of the Al-Hillah River, as the data reveal a high prevalence of multiresistance among E. coli isolates circulating at the three sampling sites.


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