scholarly journals Detex for Detection of Escherichia coli O157 in Raw Ground Beef and Raw Ground Poultry

2001 ◽  
Vol 84 (3) ◽  
pp. 752-760 ◽  
Author(s):  
Yvette M Henry ◽  
Nandini Natrajan ◽  
Wendy F Lauer
Keyword(s):  
Escherichia Coli ◽  
False Positive Rate ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Department Of Agriculture ◽  
E Coli ◽  
Metal Plating ◽  
Positive Rate ◽  
Meat Samples ◽  
Inspection Service

Abstract A method for detection of Escherichia coli O157 in beef and poultry is presented. The method is antibody-based and uses a patented antibody-specific metal-plating procedure for the detection of E. coli O157 in enriched meat samples. Both raw ground beef and raw ground poultry were tested as matrixes for the organism. The sensitivity and specificity of the assay were 98 and 90%, respectively. The accuracy of the assay was 96%. Overall, the method agreement between the E. coli O157 Detex assay and the U.S. Department of Agriculture/Food Safety Inspection Service method was 96%. Sample temperature upon loading of the apparatus was critical to the observed false-positive rate of the system.

Evaluating Lethality of Beef Roast Cooking Treatments against Escherichia coli O157:H7

2012 ◽  
Vol 75 (1) ◽  
pp. 48-61 ◽  
Author(s):  
KIMBERLY M. WIEGAND ◽  
STEVEN C. INGHAM ◽  
BARBARA H. INGHAM
Keyword(s):  
Escherichia Coli ◽  
Regression Line ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Department Of Agriculture ◽  
E Coli ◽  
Inspection Service ◽  
Whole Muscle ◽  
Nonisothermal Conditions ◽  
Added Salt

Added salt, seasonings, and phosphates, along with slow- and/or low-temperature cooking impart desirable characteristics to whole-muscle beef, but might enhance Escherichia coli O157:H7 survival. We investigated the effects of added salt, seasoning, and phosphates on E. coli O157:H7 thermotolerance in ground beef, compared E. coli O157:H7 thermotolerance in seasoned roasts and ground beef, and evaluated ground beef–derived D- and z-values for predicting destruction of E. coli O157:H7 in whole-muscle beef cooking. Inoculated seasoned and unseasoned ground beef was heated at constant temperatures of 54.4, 60.0, and 65.5°C to determine D- and z-values, and E. coli O157:H7 survival was monitored in seasoned ground beef during simulated slow cooking. Inoculated, seasoned whole-muscle beef roasts were slow cooked in a commercial smokehouse, and experimentally determined lethality was compared with predicted process lethality. Adding 5% seasoning significantly decreased E. coli O157:H7 thermotolerance in ground beef at 54.4°C, but not at 60 or 65.5°C. Under nonisothermal conditions, E. coli O157:H7 thermotolerance was greater in seasoned whole-muscle beef than in seasoned ground beef. Meeting U.S. Government (U.S. Department of Agriculture, Food Safety and Inspection Service, 1999, Appendix A) whole-muscle beef cooking guidance, which targets Salmonella destruction, would not ensure ≥6.5-log CFU/g reduction of E. coli O157:H7 in ground beef systems, but generally ensured ≥6.5-log CFU/g reduction of this pathogen in seasoned whole-muscle beef. Calculations based on D- and z-values obtained from isothermal ground beef studies increasingly overestimated destruction of E. coli O157:H7 in commercially cooked whole-muscle beef as process severity increased, with a regression line equation of observed reduction = 0.299 (predicted reduction) + 1.4373.

Food Safety and Inspection Service Regulatory Testing Program for Escherichia coli O157:H7 in Raw Ground Beef

2005 ◽  
Vol 68 (3) ◽  
pp. 462-468 ◽  
Author(s):  
ALECIA LAREW NAUGLE ◽  
KRISTIN G. HOLT ◽  
PRISCILLA LEVINE ◽  
RON ECKEL
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Ground Beef ◽  
Fiscal Year ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Inspection Service ◽  
Rate Ratios ◽  
Log Linear ◽  
Regulatory Actions

We analyzed raw ground beef testing data to determine whether a decrease in the rate of Escherichia coli O157:H7–positive raw ground beef samples has occurred since the inception of Food Safety and Inspection Service (U.S. Department of Agriculture) regulatory actions and microbiological testing concerning this commodity and pathogen. A main effects log-linear Poisson regression model was constructed to evaluate the association between fiscal year and the rate of E. coli O157: H7–positive raw ground beef samples while controlling for the effect of season for the subset of test results obtained from fiscal year (FY)2000 through FY2003. Rate ratios were used to compare the rate of E. coli O157:H7–positive raw ground beef samples between sequential years to identify year-to-year differences. Of the 26,521 raw ground beef samples tested from FY2000 through FY2003, 189 (0.71%) tested positive for E. coli O157:H7. Year-to-year comparisons identified a 50% reduction in the rate of positive ground beef samples from FY2002 to FY2003 when controlling for season (95% CI, 10 to 72% decrease; P = 0.02). This decrease was the only significant year-to-year change in the rate of E. coli O157:H7–positive raw ground beef samples but was consistent in samples obtained from both federally inspected establishments and retail outlets. We believe this decrease is attributed to specific regulatory actions by Food Safety and Inspection Service and subsequent actions implemented by the industry, with the goal of reducing E. coli O157:H7 adulteration of raw ground beef. Continued monitoring is necessary to confirm that the decrease in the rate of E. coli O157:H7 in raw ground beef samples we observed here represents the beginning of a sustained trend.

Crystal Diagnostics MultiPath System™

2014 ◽  
Vol 97 (6) ◽  
pp. 1592-1600 ◽  
Author(s):  
Curtis H Stumpf ◽  
Weidong Zhao ◽  
Brian Bullard ◽  
Christine Ammons ◽  
Karl I Devlin ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Laboratory Tests ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Department Of Agriculture ◽  
E Coli ◽  
Independent Laboratory ◽  
Diagnostics System ◽  
Inspection Service ◽  
The U.S

Abstract The Crystal Diagnostics MultiPath System™ provides rapid detection of Escherichia coli O157 in fresh raw ground beef, raw beef trim, and spinach. The Crystal Diagnostics system combines patented Liquid Crystal technology with antibody-coated paramagnetic microspheres to selectively capture and detect E. coli O157 in food matrixes. This is the only liquid crystal-based biosensor commercially available for the detection of pathogens. The Crystal Diagnostics system expeditiously provides the sensitivity and accuracy of the U.S. Department of Agriculture Food Safety Inspection Service (USDA-FSIS) and the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA-BAM) methods for detecting as low as one CFU of E. coli O157 per 375 g of raw ground beef and raw beef trim, or 200 g of raw spinach. An internal inclusivity validation demonstrated detection of all 50 tested strains of E. coli O157. The internal and independent laboratory tests demonstrate that the method is rapid and sensitive for detecting of E. coli O157 in fresh raw ground beef, beef trim, and spinach.

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.

A Screening Method for the Isolation of Escherichia coli O157:H7 from Ground Beef

1990 ◽  
Vol 53 (3) ◽  
pp. 249-252 ◽  
Author(s):  
ANITA J. G. OKREND ◽  
BONNIE E. ROSE ◽  
BARBARA BENNETT
Keyword(s):  
Escherichia Coli ◽  
Screening Method ◽  
Agar Plate ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Phenol Red ◽  
E Coli ◽  
Screening Programs ◽  
Meat Samples ◽  
Incubation Method

A screening method was developed for the isolation of Escherichia coli O157:H7 from raw ground beef. Suspensions at a 1:10 dilution of beef were made in a modified EC broth with novobiocin (mEC+n; EC broth with 1.12 g/L instead of 1.5 g/L Bile salts #3 and novobiocin at 20 mg/L). The samples were macerated in a Stomacher for 2 min and either shaken at 37°C (100 RPM) for 6 h, or incubated static at 35°C for 24 h. Appropriate dilutions of the cultures were then spread plated on 150×15 mm plates of MacConkey sorbitol agar (MSA). The MSA plates were incubated at 42°C overnight. A set of two plates consisting of a deep (40 ml/plate) phenol red sorbitol agar plate with 4-methylumbelliferyl ß-D-glucuronide (PRS-MUG), and a Levine EMB agar plate with added agar for a final concentration of 3%, were gridded into 12 numbered sections. Sorbitol negative colonies were picked from the MSA plates, spread on the appropriate section of the EMB, and stabbed into the corresponding section on the PRS-MUG plate. Those cultures that were sorbitol negative and MUG negative on PRS-MUG and were typically E. coli on EMB were confirmed biochemically and serologically. By this procedure O157:H7 was isolated from 5 of 10 meat samples inoculated at 0.6 organisms/g, and 10 of 10 samples at the 5/g level using the 6 h shaken method. With the 24 h static incubation method, O157:H7 was isolated from 8 of 10 samples at the 0.6/g level and 10 of 10 at the 5/g level. Thirteen strains of O157:H7 inoculated at levels between 0.4 and 0.6/g were tested and 9 of the 13 were isolated with the 6 h method, and 13 of the 13 with the 24 h method. The method is reliable and simple enough to be used in large screening programs.

Validation of Predictive Mathematical Models Describing the Growth of Escherichia coli O157:H7 in Raw Ground Beef

1996 ◽  
Vol 59 (12) ◽  
pp. 1331-1335 ◽  
Author(s):  
ISABEL WALLS ◽  
VIRGINIA N. SCOTT
Keyword(s):  
Escherichia Coli ◽  
Predictive Models ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Growth Data ◽  
Department Of Agriculture ◽  
Gompertz Equation ◽  
Temperature Requirements ◽  
Inspection Service ◽  
The U.S

The growth of Escherichia coli O157:H7 in raw ground beef was investigated at 12°C, 20°C, and 35°C at pH 5.7 (unadjusted) and adjusted to pH 6.3 to 6.4. These growth data were fitted to the Gompertz equation and the resulting growth kinetics were compared with predictions from the U.S. Department of Agriculture Pathogen Modeling Program. Close agreement with the model was obtained at pH 5.7, but at pH 6.4, growth was more rapid than predicted. The U.S. Department of Agriculture Food Safety and Inspection Service has used this predictive model for developing proposed regulations on time-temperature requirements for carcass cooling. As there may be considerable differences in the microenvironment of raw ground beef and a beef carcass, the validity of using predictive models for estimating growth rates on a carcass should be determined by performing growth studies on carcass surfaces.

Validation of Time and Temperature Values as Critical Limits for the Control of Escherichia coli O157:H7 during the Production of Fresh Ground Beef

2006 ◽  
Vol 69 (8) ◽  
pp. 1978-1982 ◽  
Author(s):  
J. E. MANN ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Room Temperature ◽  
Hazard Analysis ◽  
Control Point ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Meat Processing ◽  
E Coli ◽  
Critical Control Point ◽  
Critical Limits

In order to provide beef processors with valuable data to validate critical limits set for temperature during grinding, a study was conducted to determine Escherichia coli O157:H7 growth at various temperatures in raw ground beef. Fresh ground beef samples were inoculated with a cocktail mixture of streptomycin-resistant E. coli O157:H7 to facilitate recovery in the presence of background flora. Samples were held at 4.4, 7.2, and 10°C, and at room temperature (22.2 to 23.3°C) to mimic typical processing and holding temperatures observed in meat processing environments. E. coli O157:H7 counts were determined by direct plating onto tryptic soy agar with streptomycin (1,000 μg/ml), at 2-h intervals over 12 h for samples held at room temperature. Samples held under refrigeration temperatures were sampled at 4, 8, 12, 24, 48, and 72 h. Less than one log of E. coli O157:H7 growth was observed at 48 h for samples held at 10°C. Samples held at 4.4 and 7.2°C showed less than one log of E. coli O157:H7 growth at 72 h. Samples held at room temperature showed no significant increase in E. coli O157:H7 counts for the first 6 h, but increased significantly afterwards. These results illustrate that meat processors can utilize a variety of time and temperature combinations as critical limits in their hazard analysis critical control point plans to minimize E. coli O157:H7 growth during the production and storage of ground beef.

Thermal Inactivation of Escherichia coli O157: H7, Salmonella senftenberg, and Enzymes with Potential as Time-Temperature Indicators in Ground Beef

1997 ◽  
Vol 60 (5) ◽  
pp. 471-475 ◽  
Author(s):  
ALICIA ORTA-RAMIREZ ◽  
JAMES F. PRICE ◽  
YIH-CHIH HSU ◽  
GIRIDARAN J. VEERAMUTHU ◽  
JAMIE S. CHERRY-MERRITT ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Triose Phosphate ◽  
Beef Products ◽  
Z Value ◽  
D Values ◽  
Salmonella Senftenberg

The USDA has established processing schedules for beef products based on the destruction of pathogens. Several enzymes have been suggested as potential indicators of heat processing. However, no relationship between the inactivation rates of these enzymes and those of pathogenic microorganisms has been determined. Our objective was to compare the thermal inactivation of Escherichia coli O157:H7 and Salmonella senftenberg to those of endogenous muscle proteins. Inoculated and noninoculated ground beef samples were heated at four temperatures for predetermined intervals of time in thermal-death-time studies. Bacterial counts were determined and enzymes were assayed for residual activity. The D values for E. coli O157:H7 were 46.10, 6.44, 0.43, and 0.12 min at 53, 58, 63, and 68°C, respectively, with a z value of 5.60°C. The D values for S. senftenberg were 53.00, 15.17, 2.08, and 0.22 min at 53, 58, 63, and 68°C, respectively, with a z value of 6.24°C. Apparent D values at 53, 58, 63, and 68°C were 352.93, 26.31, 5.56, and 3.33 min for acid phosphatase; 6968.64, 543.48, 19.61, and 1.40 min for lactate dehydrogenase; and 3870.97, 2678.59, 769.23, and 42.92 min for peroxidase; with z values of 7.41,3.99, and 7.80°C, respectively. Apparent D values at 53, 58, 63, and 66°C were 325.03, 60.07, 3.07, and 1.34 min for phosphoglycerate mutase; 606.72, 89.86, 4.40, and 1.28 min for glyceraldehyde-3-phosphate dehydrogenase; and 153.06, 20.13, 2.25, and 0.74 min for triose phosphate isomerase; with z values of 5.18, 4.71, and 5.56°C, respectively. The temperature dependence of triose phosphate isomerase was similar to those of both E. coli O157 :H7 and S. senftenberg, suggesting that this enzyme could be used as an endogenous time-temperature indicator in beef products.

Viability of Acid-Adapted Escherichia coli O157:H7 in Ground Beef Treated with Acidic Calcium Sulfate

2004 ◽  
Vol 67 (3) ◽  
pp. 591-595 ◽  
Author(s):  
LARRY R. BEUCHAT ◽  
ALAN J. SCOUTEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Calcium Sulfate ◽  
Ground Beef ◽  
Storage Period ◽  
Acid Tolerance ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Acidic Environments ◽  
Subsequent Acid

The effects of lactic acid, acetic acid, and acidic calcium sulfate (ACS) on viability and subsequent acid tolerance of three strains of Escherichia coli O157:H7 were determined. Differences in tolerance to acidic environments were observed among strains, but the level of tolerance was not affected by the acidulant to which cells had been exposed. Cells of E. coli O157:H7 adapted to grow on tryptic soy agar acidified to pH 4.5 with ACS were compared to cells grown at pH 7.2 in the absence of ACS for their ability to survive after inoculation into ground beef treated with ACS, as well as untreated beef. The number of ACS-adapted cells recovered from ACS-treated beef was significantly (α = 0.05) higher than the number of control cells recovered from ACS-treated beef during the first 3 days of a 10-day storage period at 4°C, suggesting that ACS-adapted cells might be initially more tolerant than unadapted cells to reduced pH in ACS-treated beef. Regardless of treatment of ground beef with ACS or adaptation of E. coli O157:H7 to ACS before inoculating ground beef, the pathogen survived in high numbers.

scholarly journals Effect of Electron Beam Irradiation on Survival of Escherichia coli O157:H7 and Salmonella enterica serovar Thyphimurium in Minced Camel Meat during Refrigerated Storage

2019 ◽  
Author(s):  
A. Amiri ◽  
H. Zandi ◽  
H. Mozaffari Khosravi
Keyword(s):  
Escherichia Coli ◽  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Escherichia Coli O157 ◽  
Refrigerated Storage ◽  
Beam Irradiation ◽  
E Coli ◽  
Serovar Typhimurium ◽  
Camel Meat ◽  
Meat Samples

Background: Electron beam irradiation is one of the effective ways to control foodborne pathogens. We evaluated the effect of electron beam irradiation on survival of Escherichia coli O157:H7 and Salmonella enterica serovar Thyphimurium in minced camel meat during refrigerated storage. Methods: The meat samples were inoculated with E. coli O157:H7 and S. enterica serovar Thyphimurium and then irradiated with doses of 0, 1, 2, 3, and 5 kGy. The samples were stored at 4±1 °C and evaluated microbiologically up to 10 days. Data were analyzed using SPSS software version 18. Results: The microbial loads of minced camel meat samples were significantly reduced (p<0.0001) with increasing the dose of irradiation. The most effective dose was 5 kGy that highly reduced S. enterica serovar Typhimurium, and completely destroyed E. coli O157:H7. However, E. coli O157:H7 was more sensitive to electron beam irradiation than S. enterica serovar Typhimurium. Conclusion: Electron beam irradiation effectively reduced the population of both E. coli O157:H7 and S. enterica serovar Typhimurium in minced camel meat in a dose dependent manner.

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