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

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.

2001 ◽  
Vol 84 (3) ◽  
pp. 737-751 ◽  
Author(s):  
Charles B Bird ◽  
Rebecca J Hoerner ◽  
Lawrence Restaino ◽  
G Anderson ◽  
W Birbari ◽  
...  

Abstract Four different food types along with environmental swabs were analyzed by the Reveal for E. coli O157:H7 test (Reveal) and the Bacteriological Analytical Manual (BAM) culture method for the presence of Escherichia coli O157:H7. Twenty-seven laboratories representing academia and private industry in the United States and Canada participated. Sample types were inoculated with E. coli O157:H7 at 2 different levels. Of the 1095 samples and controls analyzed and confirmed, 459 were positive and 557 were negative by both methods. No statistical differences (p <0.05) were observed between the Reveal and BAM methods.


2006 ◽  
Vol 69 (5) ◽  
pp. 1154-1158 ◽  
Author(s):  
MARGARET L. KHAITSA ◽  
MARC L. BAUER ◽  
GREGORY P. LARDY ◽  
DAWN K. DOETKOTT ◽  
REDEMPTA B. KEGODE ◽  
...  

Cattle are an important reservoir of Escherichia coli O157:H7, which can lead to contamination of food and water, and subsequent human disease. E. coli O157:H7 shedding in cattle has been reported as seasonal, with more animals shedding during summer and early fall than during winter. North Dakota has relatively cold weather, especially in winter and early spring, compared with many other regions of the United States. The objective was to assess fecal shedding of E. coli O157: H7 in North Dakota feedlot cattle over the fall, winter, and early spring. One hundred forty-four steers were assigned randomly to 24 pens on arrival at the feedlot. Samples of rectal feces were obtained from each steer four times (October and November 2003, and March and April 2004) during finishing. On arrival (October 2003), 2 (1.4%) of 144 cattle were shedding E. coli O157:H7. The shedding increased significantly to 10 (6.9%) of 144 after 28 days (November 2003), to 76 (53%) of 143 at the third sampling (March 2004), and dropped significantly to 30 (21%) of 143 at the fourth (last) sampling (March 2004) before slaughter. Unfortunately, we were unable to sample the cattle during winter because of the extreme weather conditions. Sampling time significantly (P < 0.0001) influenced variability in E. coli O157:H7 shedding, whereas herd (P = 0.08) did not. The prevalence of E. coli O157:H7 shedding in North Dakota steers in fall and early spring was comparable to what has been reported in other parts of the United States with relatively warmer weather. Further research into E. coli O157:H7 shedding patterns during extreme weather such as North Dakota winters is warranted in order to fully assess the seasonal effect on the risk level of this organism.


1997 ◽  
Vol 60 (5) ◽  
pp. 462-465 ◽  
Author(s):  
DALE D. HANCOCK ◽  
DANIEL H. RICE ◽  
LEE ANN THOMAS ◽  
DAVID A. DARGATZ ◽  
THOMAS E. BESSER

Fecal samples from cattle in 100 feedlots in 13 states were bacteriologically cultured for Escherichia coli O157 that did not ferment sorbitol, lacked beta-glucuronidase, and possessed genes coding for Shiga-like toxin. In each feedlot 30 fresh fecal-pat samples were collected from each of four pens: with the cattle shortest on feed, with cattle longest on feed, and with cattle in two randomly selected pens. E. coli O157 was isolated from 210 (1.8%) of 11,881 fecal samples. One or more samples were positive for E. coli O157 in 63 of the 100 feedlots tested. E. coli O157 was found at roughly equal prevalence in all the geographical regions sampled. The prevalence of E. coli O157 in the pens with cattle shortest on feed was approximately threefold higher than for randomly selected and longest on feed pens. Of the E. coli O157 isolates found in this study, 89.52% expressed the H7 flagellar antigen. E. coli O157 was found to be widely distributed among feedlot cattle, but at a low prevalence, in the United States.


2006 ◽  
Vol 69 (2) ◽  
pp. 260-266 ◽  
Author(s):  
M. KAUFMANN ◽  
C. ZWEIFEL ◽  
M. BLANCO ◽  
J. E. BLANCO ◽  
J. BLANCO ◽  
...  

Fecal samples from 630 slaughtered finisher pigs were examined by PCR to assess the shedding of Escherichia coli O157 (rfbE) and Shiga toxin–producing E. coli (STEC, stx). The proportion of positive samples was 7.5% for rfbE and 22% for stx. By colony hybridization, 31 E. coli O157 and 45 STEC strains were isolated, and these strains were further characterized by phenotypic and genotypic traits. Among E. coli O157 strains, 30 were sorbitol positive, 30 had an H type other than H7, and none harbored stx genes. Intimin (eae), enterohemolysin (ehxA), EAST1 (astA), and porcine A/E–associated protein (paa) were present in 10, 3, 26, and 6% of strains. Among them, one eae-γ1–positive O157:H7 strain testing positive for ehxA and astA and two eae-α1–positive O157:H45 strains were classified as enteropathogenic E. coli (EPEC). The O157:H45 EPEC harbored the EAF plasmid and the bfpA gene, factors characteristic for typical EPEC. The isolated STEC strains (43 sorbitol positive) belonged to 11 O:H serotypes, including three previously reported in human STEC causing hemolytic uremic syndrome (O9:H−, O26:H−, and O103:H2). All but one strain harbored stx2e. The eae and ehxA genes, which are strongly correlated with human disease, were present in only one O103:H2 strain positive for stx1 and paa, whereas the astA gene was found more frequently (14 strains). High prevalence of STEC was found among finisher pigs, but according to the virulence factors the majority of these strains seem to be of low virulence.


Toxins ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 607 ◽  
Author(s):  
Gillian A.M. Tarr ◽  
Taryn Stokowski ◽  
Smriti Shringi ◽  
Phillip I. Tarr ◽  
Stephen B. Freedman ◽  
...  

Escherichia coli O157:H7 is the predominant cause of diarrhea-associated hemolytic uremic syndrome (HUS) worldwide. Its cardinal virulence traits are Shiga toxins, which are encoded by stx genes, the most common of which are stx1a, stx2a, and stx2c. The toxins these genes encode differ in their in vitro and experimental phenotypes, but the human population-level impact of these differences is poorly understood. Using Shiga toxin-encoding bacteriophage insertion typing and real-time polymerase chain reaction, we genotyped isolates from 936 E. coli O157:H7 cases and verified HUS status via chart review. We compared the HUS risk between isolates with stx2a and those with stx2a and another gene and estimated additive interaction of the stx genes. Adjusted for age and symptoms, the HUS incidence of E. coli O157:H7 containing stx2a alone was 4.4% greater (95% confidence interval (CI) −0.3%, 9.1%) than when it occurred with stx1a. When stx1a and stx2a occur together, the risk of HUS was 27.1% lower (95% CI −87.8%, −2.3%) than would be expected if interaction were not present. At the population level, temporal or geographic shifts toward these genotypes should be monitored, and stx genotype may be an important consideration in clinically predicting HUS among E. coli O157:H7 cases.


2002 ◽  
Vol 82 (4) ◽  
pp. 475-490 ◽  
Author(s):  
S. J. Bach ◽  
T. A. McAllister ◽  
D. M. Veira ◽  
V. P. J. Gannon ◽  
R. A. Holley

Escherichia coli 157:H7 has evolved as an important foodborne pathogen since its initial description in 1982. Outbreaks of illness associated with E. coli O157:H7 have been reported throughout the northern hemisphere, most frequently in Canada, the United States, Japan, and the United Kingdom. In Canada, infections due to E. coli O157: H7 appear to be more common in the western provinces than in the east, in rural vs. urban environments, and during summer as opposed to winter months. Undercooked ground beef has been implicated as the primary vehicle in E. coli O157:H7 infection, but contaminated fruits, vegetables and water have also been linked to E. coli O157:H7 outbreaks. Epidemiological investigations demonstrate that dairy and beef cattle are primary reservoirs of this organism, carrying it asymptomatically and shedding it intermittently and seasonally in their feces. Surveys in Canada and the United States indicate widespread distribution of E. coli O157:H7 in cattle operations. The prevalence of E. coli O157:H7 in cattle has been increasing in recent reports, likely due to the development of more sensitive methods for the detection of the organism. Escherichia coli O157:H7 has been isolated from feed, water for livestock, manure, soil and flies, all of which represent potential sources of contamination for cattle and their environment. To date, effective methods for controlling E. coli O157:H7 in cattle have not been identified, although dietary manipulation, vaccination and bacteriophage therapy have been reported to have potential as intervention strategies. Effective control of E. coli O157:H7 requires reducing the frequency and intensity of fecal shedding of this pathogen by cattle, in addition to targeting environmental sources of the organism. Key words: Escherichia coli O157:H7, cattle, sources, diet, transmission


2011 ◽  
Vol 74 (12) ◽  
pp. 2148-2156
Author(s):  
J. C. CHEN ◽  
B. A. CARLSON ◽  
J. N. SOFOS ◽  
G. C. SMITH ◽  
K. E. BELK ◽  
...  

Escherichia coli O157:H7 colonizes the gastrointestinal tract of ruminants asymptomatically and may enter the human food supply through fecal contamination. A fraction of individuals infected by E. coli O157:H7 develop hemolytic uremic syndrome, a life-threatening condition. When individuals infected by E. coli O157:H7 are treated with certain antibiotics, an increased incidence of hemolytic uremic syndrome may result. This finding supports the need to identify novel compounds that can either reduce the load of E. coli O157:H7 entering the human food supply or serve as alternative therapeutic treatments for infected individuals. We developed a high-throughput turbidometric assay to identify novel compounds that inhibit E. coli O157:H7 growth. Pin transfers were performed to introduce small molecule libraries into 384-well plates, where each well contained approximately 5.0 log CFU of E. coli O157:H7. Plates were incubated at 37°C for 18 h, and the optical density was measured to determine the effect of each small molecule. A total of 64,562 compounds were screened in duplicate, and 43 unique compounds inhibited E. coli O157:H7 growth. Thirty-eight of the 43 inhibitory compounds belonged to known bioactive libraries, and the other 5 compounds were from commercial libraries derived from splitting and pooling. Inhibitory compounds from known bioactive libraries were most frequently therapeutic antibiotics (n = 34) but also included an antiviral compound, a compound that disrupts the citric acid cycle, and two biguanide compounds, which have been used for various nonclinical applications. We identified two novel compounds (i.e., biguanides) that should be studied further for their ability to reduce pathogen populations in foods.


2009 ◽  
Vol 72 (6) ◽  
pp. 1272-1278 ◽  
Author(s):  
JOSEPH M. BOSILEVAC ◽  
TERRANCE M. ARTHUR ◽  
JAMES L. BONO ◽  
DAYNA M. BRICHTA-HARHAY ◽  
NORASAK KALCHAYANAND ◽  
...  

A significant portion (15 to 20%) of beef in the United States is produced in small beef processing plants that harvest fewer than 1,000 cattle per day. However, there are little data on the prevalence and levels of Escherichia coli O157:H7 and Salmonella in these processing plants. To address this lack of data, hides (n = 1,995) and carcasses (n = 1,995) of cattle at seven small processing plants located across the United States were analyzed for E. coli O157:H7 and Salmonella. Across all plants, hide prevalence of E. coli O157:H7 and Salmonella was 71 and 91%, respectively. Twelve percent of hides had E. coli O157:H7 at enumerable levels (≥40 CFU/100 cm2), while 36% of hides had Salmonella at enumerable levels. Across all plants, the prevalence of E. coli O157:H7 on preevisceration carcasses was 33%, with 2% at an enumerable level (≥0.8 CFU/100 cm2). Across all plants, Salmonella prevalence on preevisceration carcasses was 58%, with 8% at an enumerable level. Significant plant-to-plant variations in levels and prevalence of pathogens on carcasses were detected. Reduced levels of pathogens on carcasses were noted among small processors that had incorporated a hide-directed intervention. The results obtained are comparable to those observed previously for larger processors, showing that smaller beef processors face and address the same challenges as do larger beef processors.


2004 ◽  
Vol 67 (2) ◽  
pp. 295-302 ◽  
Author(s):  
MILDRED RIVERA-BETANCOURT ◽  
STEVEN D. SHACKELFORD ◽  
TERRANCE M. ARTHUR ◽  
KURT E. WESTMORELAND ◽  
GINA BELLINGER ◽  
...  

For two large beef processing plants, one located in the southern United States (plant A) and one located in the northern United States (plant B), prevalence of Escherichia coli O157:H7, Listeria spp., Listeria monocytogenes, and Salmonella was determined for hide, carcass, and facility environmental samples over the course of 5 months. The prevalence of E. coli O157: H7 (68.1 versus 55.9%) and Salmonella (91.8 versus 50.3%) was higher (P < 0.05), and the prevalence of Listeria spp. (37.7 versus 75.5%) and L. monocytogenes (0.8 versus 18.7%) was lower (P < 0.05) for the hides of cattle slaughtered at plant A versus plant B. Similarly, the prevalence of Salmonella (52.0 versus 25.3%) was higher (P < 0.05) and the prevalence of Listeria spp. (12.0 versus 40.0%) and L. monocytogenes (1.3 versus 14.7%) was lower (P < 0.05) for the fence panels of the holding pens of plant A versus plant B. The prevalence of E. coli O157:H7 (3.1 versus 10.9%), Listeria spp. (4.5 versus 14.6%), and L. monocytogenes (0.0 versus 1.1%) was lower (P < 0.05) for preevisceration carcasses sampled at plant A versus plant B. Salmonella (both plants), Listeria spp. (plant B), and L. monocytogenes (plant B) were detected on fabrication floor conveyor belts (product contact surfaces) late during the production day. For plant B, 21 of 148 (14.2%) late-operational fabrication floor conveyor belt samples were L. monocytogenes positive. For plant B, E. coli O157:H7 and L. monocytogenes were detected in preoperational fabrication floor conveyor belt samples. Overall results suggest that there are regional differences in the prevalence of pathogens on the hides of cattle presented for harvest at commercial beef processing plants. While hide data may reflect the regional prevalence, the carcass data is indicative of differences in harvest practices and procedures in these plants.


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