Prevalence of non-O157 Shiga Toxin-producing E. Coli in Children and Calves in Al- Muthanna Province, Iraq

2021 ◽  
Vol 14 (2) ◽  
pp. 78-90
Author(s):  
Ahmed Jarad ◽  
Kh. Al- Jeboori

The present study focus on non-O157 Shiga toxin-producing E. Coli (STEC), included a bacteriological study was subjected to provide additional information for non-O157 STEC prevalence in children and calves. Isolation by using selective culturing media (CHROMagar STEC and CHROMagar O157) from 127 children suffering from diarrhea and 133 calves in Al- Muthanna province. Characterization depends on culturing positive colony on MacConkey agar and Levin’s Eosin Methylene blue agar, staining single colony from the growth by gram stain, biochemical tests; Indole, the Methyl Red, Voges-Proskauer, Citrate test, Oxidase, Catalase, Urease, Motility, Kligler Iron and Api-20E, were done to confirm a diagnosis of non-O157 STEC, The reliable isolation as non-O157 STEC serotyping by specific latex agglutination test for the target non-O157 STEC (big six) serogroup (O26, O45, O103, O111, O121 and O145). The current study showed the prevalence of non-O157 STEC was 20 of out 127 (15.73%) in samples collected from children and 27 / 133 (20.30%) in calves samples in conclusion the Non-O157 STEC is an important cause of diarrhea in children, and calves; finally, the calves play an important reservoir for Non-O157 STEC.

2010 ◽  
Vol 9 (3) ◽  
pp. 76
Author(s):  
H. N. A'aiz, And F. A. Abdulla A. H. Al- Hama

This study was undertaken to detect STEC isolates, gene(Stx2) in Escherichia coli isolatesand characterize them by biochemical tests , enterohemolysin production and PCR.During aperiod of seven months (November 2007 to May 2008), a total of 280 fecal samples werecollected from 120 hospitalized children suffering from diarrhea and 160 cattle fecal samples .Feces specimens were screened for the presence of NSF E. coli and STEC by cultured onsorbitol MacConkey agar (SMAC).A total of 209 (74.6%) non-sorbitol fermenting (NSF)bacterial isolates were obtained , 69 (57.5%) from children fecal samples and 140 (87.5%) fromcattle feces . Of which 5 (4.16%) NSF E. coli isolated from children fecal samples and 38(23.75%) from cattle feces. NSF isolates were identified as Shiga toxin producing E. coli(STEC), but only 16 (10%) isolates of cattle and 2 (1.6%)isolates of children were PCR-positivefor (Stx2) gene which gave amplification bands at 346 bp using DNA marker in the interpretationof the results. Among 18 STEC studied, a total of 16 (88.8%) isolates expressed enterohemolysinon washing sheep blood agar plates.On the other hand, the study was showed that the sensitivityand specificity of PCR technique in diagnosis of STEC were 41.8% , 100% respectively, incomparison with other tests like biochemical tests, sensitivity and specificity of these tests were(100% , 86.9%) respectively.


2005 ◽  
Vol 68 (8) ◽  
pp. 1593-1599 ◽  
Author(s):  
MICHAEL A. GRANT

A new procedure for enrichment of Escherichia coli O157:H7 and other Shiga toxin–producing E. coli was compared to five standard methods: the British Public Health Laboratory Service, International Standard Method, U.S. Department of Agriculture, Canadian Health Products and Food Branch, and U.S. Food and Drug Administration. The new procedure was comparable to the standard methods in its ability to detect target cells inoculated into foods at approximately 1 CFU g−1. Comparisons were also made of the ability of the six enrichment procedures to detect E. coli O157:H7 against a large background of competitor microorganisms. In these experiments the new procedure yielded more target cells than the other five enrichments by two to three orders of magnitude as determined by enumeration on sorbitol MacConkey agar with tellurite and cefixime and Rainbow agar with tellurite and novobiocin and by verification of presumptive colonies by real-time PCR. For example, the population of enterohemorrhagic E. coli strain 6341 recovered on sorbitol MacConkey agar with tellurite and cefixime after enrichment with the experimental method was 2.42 × 108 CFU ml−1 and 1.80 × 106 CFU ml−1 after enrichment with the Canadian Health Products and Food Branch method, the second most effective in this experiment. In addition, broth cultures resulting from each of the six enrichment procedures were used to prepare templates for real-time PCR detection of stx1/stx2. Resulting threshold cycle (Ct) values after the experimental enrichment were similar to positive control values, whereas the five standard methods produced delayed Ct values or were not detected.


2019 ◽  
Vol 23 (10) ◽  
pp. 40 ◽  
Author(s):  
Wisal R. Yaseen AL- Hayali1 ◽  
Alaa Younis Mahdy2 ◽  
Muhammad Abdul Zaraq Ibrahim3

This study was designed to detect the presence of genes encoding autotranspoter proteins in E. coli that causes UTI by using PCR techniques. Seventy two urine sample were collected from patients infected with UTI whom attended to Salah-AL-deen general hospital in Tikrit city, during three months period (September to November 2016). All samples were cultivated on Blood agar and MacConkey agar. The 47(65.2%) E. coli isolates were confirmed using standard biochemical tests for E. coli. The results indicate the frequencies of Sat gene was 27 strains(57.5%) while Vat gene was 12 strains (25.5%) while the Duplex PCR detected 8(17%) strains of E. coli contained two genes. With this method, we confirmed that autotransporter genes are pathospecifically distributed among the E. coli strains studied.   http://dx.doi.org/10.25130/tjps.23.2018.167


2020 ◽  
Author(s):  
Dawood Al-Ajmi ◽  
Shafeeq Rahman ◽  
Sharmila Banu

Abstract Background: Shiga toxin-producing Escherichia coli (STEC) are associated with major food illness around the world. E.coli O157, has been widely reported as the most common STEC serogroup, and has emerged as an important enteric pathogen. Further, cattle have been identified as a major E. coli O157:H7 reservoir for human infection; however, the ecology of this organism in camels, sheep and goats is less understood. The current study aims to evaluate the prevalence of E. coli serotype O157 in feces of cattle, camels, sheep and goats slaughtered in United Arab Emirates (UAE) for meat consumption. This study was carried out on fecal samples of healthy cattle (n = 137), camels (n = 140), sheep (n = 141) and goats (n = 150) during the period of September 2017 to August 2018. We have used the traditional sensitive immunomagnetic separation technique (IMS) coupled with a culture plating method for detection of E. coli O157. Non-sorbitol fermenting colonies were assessed via the latex agglutination test and the positive cultures were subjected to PCR for detection of attaching and effacing genes (eaeA), hemolysin A (hlyA) and Shiga toxin-producing genes (stx1 and stx2) and genes specific for E. coli O157:H7 (rfb O157, uid A and flic H7). All E. coli O157 isolates were analyzed for their susceptibility pattern toward 20 select antibiotics.Results: E. coli O157 was present in the fecal samples of goats, camels and cattle at 2%, 3.3%, and 1.6%, respectively. In sheep we failed to detect any E. coli O157 strains. The most prevalent E.coli O157 gene identified across all species’ isolates was stx2, while stx1 was not detected in any of the samples. ­After testing samples from camels, goats and cattle, Cefotaxime (100%), Chloramphenicol (100%), Ciprofloxacin (100%), Norfloxacin (100%) and Polymixin B (100%) showed susceptibility showed susceptibility to all E.coli O157 isolates.Conclusion: This is the first study, to our knowledge, to report on the prevalence of E. coli O157 in the slaughter animals in UAE and clearly demonstrates the presence of these pathogens in slaughtered animals, which could possibly contaminate the meat products intended for human consumption.


2000 ◽  
Vol 38 (4) ◽  
pp. 1684-1687 ◽  
Author(s):  
Hiroshi Fukushima ◽  
Ken Hoshina ◽  
Manabu Gomyoda

Culture on cefixime, tellurite, and sorbitol-MacConkey agar after HCl treatment facilitated the growth of 410 (94%) of 436eae-positive Shiga toxin-producing Escherichia coli (STEC) strains and 17 (16%) of 107 eae-negative STEC strains. This selectivity was closely related to acid resistance in E. coli and tellurite resistance ineae-positive STEC strains.


2014 ◽  
Vol 142 (12) ◽  
pp. 2548-2558 ◽  
Author(s):  
H. IRSHAD ◽  
A. L. COOKSON ◽  
D. J. PRATTLEY ◽  
M. DUFOUR ◽  
N. P. FRENCH

SUMMARYThe objective of this study was to determine the distribution of Shiga toxin-producingEscherichia coli(STEC) virulence markers (stx1,stx2,eae,ehxA) inE. colistrains isolated from young calves aged fewer than 7 days (bobby calves). In total, 299 recto-anal mucosal swabs were collected from animals at two slaughter plants and inoculated onto tryptone bile X-glucuronide and sorbitol MacConkey agar supplemented with cefixime and potassium tellurite. Isolates were analysed using multiplex polymerase chain reaction to detectstx1,stx2,eaeandehxAgenes. The most common combination of virulence markers wereeae, ehxA(n = 35) followed byeae(n = 9). In total, STEC and atypical enteropathogenicE. coli(aEPEC) were isolated from 8/299 (2·6%) and 37/299 (12·3%) calves, respectively. All the isolates could be assigned to 15 genotype clusters with >70% similarity cut-off usingXbaI pulsed-field gel electrophoresis. It may be concluded that healthy calves from the dairy industry are asymptomatic carriers of a diverse population of STEC and aEPEC in New Zealand.


2021 ◽  
Author(s):  
Ghassan Tayh ◽  
Salma Mariem Boubaker ◽  
Rym Ben Khedher ◽  
Mounir Jbeli ◽  
Faten Ben Chehida ◽  
...  

Abstract Background: Shiga toxin-producing Escherichia coli (STEC) O157:H7 is associated with intestinal infection in human and considered a main cause of food-borne diseases. It was isolated from animals, human and food. The aim of the study was to assess the incidence of E. coli O157:H7 in fecal samples of healthy cattle collected in slaughterhouses (n=160) and from farms (n=100).Methods: E. coli isolates were detected on MacConkey agar. A total of 236 E. coli isolates were recovered from fecal samples of healthy cattle. We used sorbitol MacConkey to detect non-sorbitol fermenting colonies that were examined for the presence of O157 antigen by latex agglutination, and positive bacteria were screened for the existence of stx1, stx2, eaeA and ehxA by PCR as well as rfbEO157 and fliCH7 genes specific for serotype O157. All isolates were examined for the susceptibility against 21antibiotics discs.Results: Of the 236 E. coli isolates, 4.2% (10/236) were positive for STEC O157:H7. Shiga toxin gene (stx2) was present in 70% of isolates, stx1 and ehxA were confirmed in 60% of the isolates, whereas eae was identified in two isolates. Other virulence factors screened (fimH, sfa/focDE, cdt3, traT, iutA and hly) were present among the 10 isolates. All E. coli O157:H7 isolates were sensitive to amoxicillin/clavulanic acid, cefotaxime, cefepime, aztreonam, colistin and sulfamethoxazole/trimethoprim. All isolates belong to the phylo-group E.Conclusion: This is the first study of the incidence of E. coli O157:H7 in cattle in Tunisia. Our finding proves the existence of STEC O157:H7 in healthy animals producing food for human consumption which could be a source of human contamination.


2006 ◽  
Vol 69 (3) ◽  
pp. 689-692 ◽  
Author(s):  
KIERAN N. JORDAN ◽  
MATTHEW M. MAHER

The direct detection and estimation of concentration of Escherichia coli O157:H7 down to 1 CFU/g of cheese was achieved by conventional plating techniques. Cheese was manufactured with unpasteurized milk inoculated with E. coli O157: H7 at 34 ± 3 CFU/ml. The numbers of E. coli O157:H7 were monitored during cheese ripening by plating on sorbitol MacConkey agar supplemented with cefixime and potassium tellurite (CT-SMAC) and on CT-O157:H7 ID medium. Using the pour plate method, E. coli O157:H7 colonies could easily be distinguished from non-O157:H7 colonies on CT-O157:H7 ID medium but not on CT-SMAC. Higher numbers of E. coli O157:H7 were detectable with O157:H7 ID medium. Latex agglutination and PCR were used to confirm the identification of typical E. coli O157:H7 colonies, and nontypical colonies as not being E. coli O157:H7. As few as 1 CFU/g of cheese could be detected. E. coli O157:H7 also was detected in deliberately contaminated milk at concentrations as low as 4 CFU/10 ml.


2013 ◽  
Vol 79 (18) ◽  
pp. 5710-5720 ◽  
Author(s):  
Shuang Yin ◽  
Mark A. Jensen ◽  
Jiawei Bai ◽  
Chitrita DebRoy ◽  
Rodolphe Barrangou ◽  
...  

ABSTRACTThe Shiga toxin-producingEscherichia coli(STEC) strains, including those of O157:H7 and the “big six” serogroups (i.e., serogroups O26, O45, O103, O111, O121, and O145), are a group of pathogens designated food adulterants in the United States. The relatively conserved nature ofclusteredregularlyinterspacedshortpalindromicrepeats (CRISPRs) in phylogenetically relatedE. colistrains makes them potential subtyping markers for STEC detection, and a quantitative PCR (qPCR)-based assay was previously developed for O26:H11, O45:H2, O103:H2, O111:H8, O121:H19, O145:H28, and O157:H7 isolates. To better evaluate the sensitivity and specificity of this qPCR method, the CRISPR loci of 252 O157 and big-six STEC isolates were sequenced and analyzed along with 563 CRISPR1 and 624 CRISPR2 sequences available in GenBank. General conservation of spacer content and order was observed within each O157 and big-six serogroup, validating the qPCR method. Meanwhile, it was found that spacer deletion, the presence of an insertion sequence, and distinct alleles within a serogroup are sources of false-negative reactions. Conservation of CRISPR arrays among isolates expressing the same flagellar antigen, specifically, H7, H2, and H11, suggested that these isolates share an ancestor and provided an explanation for the false positives previously observed in the qPCR results. An analysis of spacer distribution acrossE. colistrains provided limited evidence for temporal spacer acquisition. Conversely, comparison of CRISPR sequences between strains along the stepwise evolution of O157:H7 from its O55:H7 ancestor revealed that, over this ∼7,000-year span, spacer deletion was the primary force generating CRISPR diversity.


2002 ◽  
Vol 65 (5) ◽  
pp. 752-759 ◽  
Author(s):  
S. E. MURINDA ◽  
L. T. NGUYEN ◽  
S. J. IVEY ◽  
B. E. GILLESPIE ◽  
R. A. ALMEIDA ◽  
...  

A study on the prevalence of Escherichia coli O157:H7 was conducted on 30 dairy farms in east Tennessee between May 2000 and April 2001. This pathogen was isolated from 8 of 30 (26.7%) dairy farms at various sampling times. A total of 415 fecal samples from cull dairy cows and 268 bulk tank milk samples were analyzed. Overall, 10 of 683 (1.46%) samples (2 of 268 [0.75%] milk samples and 8 of 415 [1.93%] fecal samples) tested positive for E. coli O157:H7. Food and Drug Administration Bacteriological Analytical Manual protocols were used for the conventional isolation and confirmation of E. coli O157:H7. Samples were shake cultured (150 rpm) at 42°C for 24 h in tryptic soy broth containing 2 mg of novobiocin per liter. White colonies isolated on cefixime-tellurite sorbitol MacConkey agar plates were evaluated for fluorescence on sorbitol MacConkey agar supplemented with 0.025 g of methylumbelliferyl-β-d-glucuronide per liter. Nonfluorescing white colonies were biochemically typed and serologically confirmed. Multiplex polymerase chain reaction profiles of E. coli O157: H7 isolates indicated the presence of common virulence factors (Shiga toxin, enterohemolysin, and intimin) of Shiga toxin–producing E. coli, suggesting the potential human pathogenicity of bacterial isolates. Pulsed-field gel electrophoresis profiles of SpeI and XbaI restriction enzyme–digested genomic DNA were used to establish relatedness among bacterial isolates. Data from this study indicate that both cull dairy cows and bulk tank milk pose a potential hazard with regard to human foodborne illness. It is therefore imperative to develop on-farm and preharvest pathogen reduction programs to control the carriage of E. coli O157:H7 pathogens.


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