Comparison of Enrichment Procedures for Shiga Toxin–Producing Escherichia coli in Wastes from Commercial Swine Farms†

2009 ◽  
Vol 72 (9) ◽  
pp. 1982-1986 ◽  
Author(s):  
MICHAEL A. GRANT ◽  
MARK A. MOGLER ◽  
DELBERT L. HARRIS
Keyword(s):  
Escherichia Coli ◽  
Drug Administration ◽  
Shiga Toxin ◽  
Swine Production ◽  
Department Of Agriculture ◽  
E Coli ◽  
Swine Farms ◽  
Heat Stable ◽  
Enrichment Procedure ◽  
Pooled Samples

Three methods for enrichment of Shiga toxin–producing Escherichia coli (STEC) were compared using waste pit samples from swine production facilities housing 50 to 3,000 animals. The STEC gene stx2 was detected in 5 of 17 pooled samples using a U.S. Department of Agriculture (USDA) enrichment procedure, 6 of 17 samples using a U.S. Food and Drug Administration (FDA) enrichment procedure, and 8 of 17 samples using an experimental acid enrichment. All isolates were non-O157 and 5 of 6 were positive for enterotoxigenic E. coli–associated heat stable toxins a and b. The three enrichment procedures were also tested for their ability to support growth of 31 strains of STEC. The acid enrichment media supported growth of 100% of the strains, the FDA medium supported 77% of the strains, and the USDA medium supported 16% of the strains.

scholarly journals Prevalence of a Gene Encoding Adhesin Involved in Diffuse Adherence among Escherichia Coli Isolates in Pigs with Postweaning Diarrhea or Edema Disease

2003 ◽  
Vol 15 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Seung-Kwon Ha ◽  
Changsun Choi ◽  
Chanhee Chae
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Coli Strain ◽  
Isolation Rate ◽  
Gene Encoding ◽  
Edema Disease ◽  
E Coli ◽  
Heat Stable ◽  
Fimbrial Adhesins ◽  
Postweaning Diarrhea

A total of 604 Escherichia coli strains isolated from weaned pigs with diarrhea or edema disease on 653 swine farms were screened for the presence of the adhesin involved in diffuse adherence (AIDA) gene by polymerase chain reaction (PCR). Escherichia coli isolates that carried AIDA genes were also tested by PCR for the detection of 5 fimbriae (F4, F5, F6, F18, and F41), 3 heat-stable (STa, STb, and EAST1) and 1 heat-labile (LT) enterotoxin, and Shiga toxin 2e (Stx2e) genes. Forty-five (7.5%) of the 604 E. coli isolates carried the gene for AIDA. Of these 45 isolates, 5 (11.1%) carried EAST1 genes only, 1 (2.2%) carried genes for at least one of the fimbrial adhesins, 12 (26.7%) carried genes for at least one of the toxins, and 27 (60%) carried genes for at least one of the fimbrial adhesins and toxins. Fifty-one percent of strains that carried AIDA genes carried Stx2e genes, and 40% of strains that carried AIDA genes carried F18ab. The isolation rate of enterotoxigenic E. coli strain carrying genes for AIDA was 87%, and the isolation rate of Shiga toxin-producing E. coli strain carrying genes for AIDA was 49%. AIDA may represent an important virulence determinant in pigs with postweaning diarrhea or edema disease.

scholarly journals Molecular Characterization of Shiga Toxin-Producing Escherichia coli Strains Isolated in Poland

2016 ◽  
Vol 65 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Aleksandra Januszkiewicz ◽  
Waldemar Rastawicki
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Virulence Gene ◽  
Virulence Determinants ◽  
E Coli ◽  
Heat Stable ◽  
Food Borne ◽  
Wide Range ◽  
Uremic Syndrome

Shiga toxin-producing Escherichia coli (STEC) strains also called verotoxin-producing E. coli (VTEC) represent one of the most important groups of food-borne pathogens that can cause several human diseases such as hemorrhagic colitis (HC) and hemolytic – uremic syndrome (HUS) worldwide. The ability of STEC strains to cause disease is associated with the presence of wide range of identified and putative virulence factors including those encoding Shiga toxin. In this study, we examined the distribution of various virulence determinants among STEC strains isolated in Poland from different sources. A total of 71 Shiga toxin-producing E. coli strains isolated from human, cattle and food over the years 1996 – 2010 were characterized by microarray and PCR detection of virulence genes. As stx1a subtype was present in all of the tested Shiga toxin 1 producing E. coli strains, a greater diversity of subtypes was found in the gene stx2, which occurred in five subtypes: stx2a, stx2b, stx2c, stx2d, stx2g. Among STEC O157 strains we observed conserved core set of 14 virulence factors, stable in bacteria genome at long intervals of time. There was one cattle STEC isolate which possessed verotoxin gene as well as sta1 gene encoded heat-stable enterotoxin STIa characteristic for enterotoxigenic E. coli. To the best of our knowledge, this is the first comprehensive analysis of virulence gene profiles identified in STEC strains isolated from human, cattle and food in Poland. The results obtained using microarrays technology confirmed high effectiveness of this method in determining STEC virulotypes which provides data suitable for molecular risk assessment of the potential virulence of this bacteria.

Prevalence and Characterization of Escherichia coli O157:H7 on Pork Carcasses and in Swine Colon Contents from Provincially Licensed Abattoirs in Alberta, Canada

2020 ◽  
Vol 83 (11) ◽  
pp. 1909-1917
Author(s):  
SAIDA ESSENDOUBI ◽  
XIANQIN YANG ◽  
ROBIN KING ◽  
JULIA KEENLISIDE ◽  
JAVIER BAHAMON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Gel Electrophoresis ◽  
Mean Value ◽  
Pulsed Field Gel Electrophoresis ◽  
Escherichia Coli O157 ◽  
Pulsed Field ◽  
E Coli ◽  
Swine Farms

ABSTRACT The objective of this study was to determine the prevalence of Shiga toxin–producing Escherichia coli (STEC) O157:H7 in colon contents and on carcasses from pigs slaughtered at provincially licensed abattoirs (PLAs) in Alberta, Canada. In 2017, carcass sponge samples and colon content samples were collected from 504 healthy market hogs at 39 PLAs and analyzed for E. coli O157:H7. Carcass samples were also analyzed for E. coli and aerobic colony count (ACC). Nine (1.8%) of 504 carcass samples were confirmed positive for E. coli O157:H7. Seven (1.4%) of 504 colon content samples were confirmed positive for E. coli O157:H7. These positives were found in 5 (12.8%) of 39 PLAs from hogs originating from eight farms. The E. coli O157:H7 isolates recovered from the positive samples (n = 1 isolate per sample) were clonal, as determined by pulsed-field gel electrophoresis. Six E. coli O157:H7 isolates obtained over 8 months from one PLA that only processed hogs and sourced hogs from one farm had indistinguishable pulsed-field gel electrophoresis patterns. All 16 E. coli O157:H7 isolates harbored eae and ehxA and were of stx2a subtype, suggesting that swine can carry E. coli O157:H7 of importance to human health. All carcass sponge swabs (100%) were positive for ACC. E. coli was present in 72% of carcass swabs. Carcasses from PLAs slaughtering both beef and hogs had a numerically higher ACC mean value but not statistically different compared with the carcasses from PLAs slaughtering only swine (2,799 and 610 CFU/cm2, respectively). E. coli showed a similar trend with a mean value of 0.88 CFU/cm2 in PLAs slaughtering both species and 0.26 CFU/cm2 in PLAs slaughtering only swine (P ≤ 0.05). This study provides evidence that healthy market hogs from different producers and farms in Alberta can carry E. coli O157:H7, and some strains of the organism may be able to establish persistence on some swine farms. HIGHLIGHTS

Evaluating the Efficacy of Three U.S. Department of Agriculture–Approved Antimicrobial Sprays for Reducing Shiga Toxin–Producing Escherichia coli Surrogate Populations on Bob Veal Carcasses

2016 ◽  
Vol 79 (6) ◽  
pp. 956-962 ◽  
Author(s):  
N. J. SEVART ◽  
N. BAUMANN ◽  
H. THIPPAREDDI ◽  
T. A. HOUSER ◽  
J. B. LUCHANSKY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Control Point ◽  
Spray Application ◽  
Department Of Agriculture ◽  
E Coli ◽  
Log Reduction ◽  
Instrumental Color ◽  
Antimicrobial Intervention ◽  
Spray Treatment

ABSTRACT Effective antimicrobial intervention strategies to reduce Shiga toxin–producing Escherichia coli (STEC) risks associated with veal are needed. This study evaluated the efficacy of lactic acid (4.5%, pH 2.0), Citrilow (pH 1.2), and Beefxide (2.25%, pH 2.3) for reducing STEC surrogates on prerigor and chilled bob veal carcasses and monitored the effects of these interventions on chilled carcass color. Dehided bob veal carcasses were inoculated with a five-strain cocktail of rifampin-resistant, surrogate E. coli bacteria. E. coli surrogates were enumerated after inoculation, after water wash, after prechill carcass antimicrobial spray application, after chilling for 24 h, and after postchill carcass antimicrobial spray application; carcass color was measured throughout the process. A standard carcass water wash (~50°C) reduced the STEC surrogate population by 0.9 log CFU/cm2 (P ≤ 0.05). All three antimicrobial sprays applied to prerigor carcasses delivered an additional ~0.5-log reduction (P ≤ 0.05) of the surrogates. Chilling of carcasses for 24 h reduced (P ≤ 0.05) the surrogate population by an additional ~0.4 log cycles. The postchill application of the antimicrobial sprays provided no further reductions. Carcass L*, a*, and b* color values were not different (P > 0.05) among carcass treatments. Generally, the types and concentrations of the antimicrobial sprays evaluated herein did not negatively impact visual or instrumental color of chilled veal carcasses. This study demonstrates that warm water washing, followed by a prechill spray treatment with a low-pH chemical intervention, can effectively reduce STEC risks associated with veal carcasses; this provides processors a validated control point in slaughter operations.

A Novel Selective Medium for Simultaneous Enrichment of Shiga Toxin–Producing Escherichia coli and Salmonella in Ground Beef

2018 ◽  
Vol 81 (8) ◽  
pp. 1252-1257 ◽  
Author(s):  
JOSEPH EGGERS ◽  
JOELLEN M. FEIRTAG ◽  
ALAN D. OLSTEIN ◽  
JOSEPH M. BOSILEVAC
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Ground Beef ◽  
Performance Standards ◽  
Selective Medium ◽  
Microbiological Analysis ◽  
Department Of Agriculture ◽  
Selective Enrichment ◽  
E Coli ◽  
Inspection Service

ABSTRACT Microbiological analysis of ground beef for contamination by both Salmonella and Shiga toxin–producing Escherichia coli (STEC) is performed by the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS), as part of its Performance Standards Verification Testing program. FSIS has established a zero tolerance for STEC serotype O157:H7 and serogroups O26, O45, O103, O111, O121, and O145 because they are regarded as adulterants. The detection and isolation of these specific serogroups presents a technical challenge necessitating time-consuming and costly laboratory procedures that often exceed the technical capabilities of many small internal and reference laboratories. We describe here a method using a novel STEC and Salmonella selective (SSS) broth that allows for simultaneous selective enrichment of STEC and Salmonella sp., providing isolation and detection from the same broth. The method only involves direct plating from beef enrichments to detect suspect isolates that can be easily confirmed by using immunoassays or PCR, rendering the isolation simpler and less costly than the current described methods. In a side-by-side comparison with modified tryptic soy broth (mTSB), the use of SSS broth resulted in primarily isolating STEC and Salmonella sp., while substantially suppressing the growth of other gram-negative Enterobacteriacae by 90%. Significantly more (χ2 < 3.84) samples containing E. coli O157:H7 and STEC O26, O111, O121, and O145 and a nondifferent (χ2 > 3.84) number of samples containing STEC O103 and O45 were identified when enriching in SSS broth. Coenrichment using six different Salmonella serovars showed numerically greater but not significant (χ2 < 3.84) positive samples by using SSS broth compared with mTSB for a majority of serotypes.

scholarly journals Virulence Genes in Expanded-Spectrum-Cephalosporin-Resistant and -Susceptible Escherichia coli Isolates from Treated and Untreated Chickens

2015 ◽  
Vol 60 (3) ◽  
pp. 1874-1877 ◽  
Author(s):  
S. Baron ◽  
S. Delannoy ◽  
S. Bougeard ◽  
E. Larvor ◽  
E. Jouy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Phylogenetic Groups ◽  
Content Type ◽  
E Coli ◽  
Heat Stable ◽  
Intestinal Infections

This study investigated antimicrobial resistance, screened for the presence of virulence genes involved in intestinal infections, and determined phylogenetic groups ofEscherichia coliisolates from untreated poultry and poultry treated with ceftiofur, an expanded-spectrum cephalosporin. Results show that none of the 76 isolates appeared to be Shiga toxin-producingE. colior enteropathogenicE. coli. All isolates were negative for the major virulence factors/toxins tested (ehxA,cdt, heat-stable enterotoxin [ST], and heat-labile enterotoxin [LT]). The few virulence genes harbored in isolates generally did not correlate with isolate antimicrobial resistance or treatment status. However, some of the virulence genes were significantly associated with certain phylogenetic groups.

scholarly journals Presence of Escherichia coli O157 and O157:H7 in raw milk and Van herby cheese

2015 ◽  
Vol 59 (4) ◽  
pp. 511-514 ◽  
Author(s):  
Yakup Can Sancak ◽  
Hakan Sancak ◽  
Ozgur Isleyici
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Drug Administration ◽  
Shiga Toxin ◽  
Raw Milk ◽  
Escherichia Coli O157 ◽  
Human Pathogens ◽  
Emerging Pathogens ◽  
E Coli ◽  
Milk Samples

Abstract The Shiga toxin-producing Escherichia coli (STEC) strains are currently considered important emerging pathogens threatening public health. Among Shiga toxin-producing Escherichia coli, E. coli O157:H7 strains have emerged as important human pathogens. This study was conducted to determine the presence of Escherichia coli O157 and O157:H7 in raw milk samples and Van herby cheese samples. For this purpose, 100 samples of raw milk were collected and 100 samples of herby cheese sold for consumption in Van province in Turkey were obtained from grocers and markets in order to detect the presence of Escherichia coli O157 and O157:H7. The method of E. coli O157 and O157:H7 isolation proposed by the Food and Drug Administration (FDA) was used. E. coli O157 in raw milk and herby cheese samples was found in 11% and 6% of samples respectively, and E. coli O157:H7 was found in 2% of herby cheese samples. No E. coli O157:H7 was detected in raw milk samples. This study showed that raw milk was contaminated with E. coli O157 and herby cheese was contaminated with both E. coli O157 and E. coli O157:H7; therefore, herby cheese poses a serious risk to public health.

scholarly journals Genomic Characteristics of Stx2e-Producing Escherichia coli Strains Derived from Humans, Animals, and Meats

Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1551
Author(s):  
Xi Yang ◽  
Yannong Wu ◽  
Qian Liu ◽  
Hui Sun ◽  
Ming Luo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Wide Distribution ◽  
Genetic Characteristics ◽  
E Coli ◽  
Heat Stable ◽  
Genetic Feature ◽  
Genetic Features ◽  
Encoding Genes ◽  
Different Sources

Shiga toxin (Stx) can be classified into two types, Stx1 and Stx2, and different subtypes. Stx2e is a subtype commonly causing porcine edema disease and rarely reported in humans. The purpose of this study was to analyze the prevalence and genetic characteristics of Stx2e-producing Escherichia coli (Stx2e-STEC) strains from humans compared to strains from animals and meats in China. Stx2e-STEC strains were screened from our STEC collection, and whole-genome sequencing was performed to characterize their genetic features. Our study showed a wide distribution of Stx2e-STEC among diverse hosts and a higher proportion of Stx2e-STEC among human STEC strains in China. Three human Stx2e-STEC isolates belonged to O100:H30, Onovel26:H30, and O8:H9 serotypes and varied in genetic features. Human Stx2e-STECs phylogenetically clustered with animal- and food-derived strains. Stx2e-STEC strains from animals and meat showed multidrug resistance, while human strains were only resistant to azithromycin and tetracycline. Of note, a high proportion (55.9%) of Stx2e-STEC strains, including one human strain, carried the heat-stable and heat-labile enterotoxin-encoding genes st and lt, exhibiting a STEC/enterotoxigenic E. coli (ETEC) hybrid pathotype. Given that no distinct genetic feature was found in Stx2e-STEC strains from different sources, animal- and food-derived strains may pose the risk of causing human disease.

scholarly journals Interlaboratory Evaluation of the U.S. Food and Drug Administration Escherichia coli Identification Microarray for Profiling Shiga Toxin–Producing Escherichia coli

2018 ◽  
Vol 81 (8) ◽  
pp. 1275-1282 ◽  
Author(s):  
ISHA R. PATEL ◽  
JAYANTHI GANGIREDLA ◽  
DAVID W. LACHER ◽  
MARK K. MAMMEL ◽  
LORI BAGI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quality Assurance ◽  
Drug Administration ◽  
Shiga Toxin ◽  
Food And Drug Administration ◽  
External Quality Assurance ◽  
External Quality ◽  
E Coli ◽  
Molecular Serotyping ◽  
The U.S

ABSTRACT The U.S. Food and Drug Administration Escherichia coli Identification (FDA-ECID) microarray provides rapid molecular characterization of E. coli. The effectiveness of the FDA-ECID for characterizing Shiga toxin–producing E. coli (STEC) was evaluated by three federal laboratories and one reference laboratory with a panel of 54 reference E. coli strains from the External Quality Assurance program. Strains were tested by FDA-ECID for molecular serotyping (O and H antigens), Shiga toxin subtyping, and the presence of the ehxA and eae genes for enterohemolysin and intimin, respectively. The FDA-ECID O typing was 96% reproducible among the four laboratories and 94% accurate compared with the reference External Quality Assurance data. Discrepancies were due to the absence of O41 target loci on the array and to two pairs of O types with identical target sequences. H typing was 96% reproducible and 100% accurate, with discrepancies due to two strains from one laboratory that were identified as mixed by FDA-ECID. Shiga toxin (Stx) type 1 subtyping was 100% reproducible and accurate, and Stx2 subtyping was 100% reproducible but only 64% accurate. FDA-ECID identified most Stx2 subtypes but had difficulty distinguishing among stx2a, stx2c, and stx2d genes because of close similarities of these sequences. FDA-ECID was 100% effective for detecting ehxA and eae and accurately subtyped the eae alleles. This interlaboratory study revealed that FDA-ECID for STEC characterization was highly reproducible for molecular serotyping, stx and eae subtyping, and ehxA detection. However, the array was less useful for distinguishing among the highly homologous O antigen genes and the stx2a, stx2c, and stx2d subtypes.

scholarly journals Multiplex PCR for Enterotoxigenic, Attaching and Effacing, and Shiga Toxin-Producing Escherichia coli Strains from Calves

1998 ◽  
Vol 36 (6) ◽  
pp. 1795-1797 ◽  
Author(s):  
Sophia M. Franck ◽  
Brad T. Bosworth ◽  
Harley W. Moon
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Shiga Toxin ◽  
Shiga Toxins ◽  
E Coli ◽  
Heat Stable ◽  
Genes Encoding

A multiplex PCR was developed to identify enterotoxigenic, attaching and effacing, and Shiga toxin-producing Escherichia coli strains by amplifying genes encoding K99 and F41 fimbriae, heat-stable enterotoxin a, intimin, and Shiga toxins 1 and 2. This multiplex PCR was specific and sensitive. It will be useful for identification of E. coli strains which cause diarrhea in calves.

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