Validation of a Modified ANSR® for E. coli O157:H7 Method for Detection of E. coli O157:H7 in Select Foods

2019 ◽  
Vol 102 (1) ◽  
pp. 96-107
Author(s):  
Susan Alles ◽  
Brooke Roman ◽  
Quynh-Nhi Le ◽  
Edan Hosking ◽  
Wesley Colangelo ◽  
...  
Keyword(s):  
Validation Study ◽  
Laboratory Testing ◽  
Ground Beef ◽  
Nucleic Acid Amplification ◽  
Method Performance ◽  
E Coli ◽  
Independent Laboratory ◽  
Accelerated Stability ◽  
Nucleic Acid Amplification Technology ◽  
The U.S

Abstract Background: The ANSR method is based on isothermal nucleic acid amplification technology. The modifications to assay components improve sensitivity of the assay and robustness of the internal positive control. Objective: A Performance Tested MethodSM validation study was conducted to assess performance of a modified version of the ANSR® for Escherichia coli O157:H7 method. Methods: The validation study included inclusivity/exclusivity, matrix, robustness, accelerated stability, and independent laboratory testing. Results: In inclusivity testing of 55 strains of E. coli O157:H7 and E. coli O157:NM variants, all strains produced positive results. In exclusivity testing of 41 strains including E. coli of other serotypes and bacteria of closely related genera, all strains produced negative results. In matrix testing of beef trim, raw ground beef, spinach, and sprout-irrigation water, ANSR method performance was compared with that of the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook or the U.S. Food and Drug Administration Bacteriological Analytical Manual reference culture procedures. Conclusions: all trials, ANSR method performance was not statistically different from that of the reference methods. Results of independent laboratory testing of ground beef corroborated those of internal testing. Introducing modest changes to three assay operating parameters did not materially affect ANSR method performance. Finally, accelerated stability testing results of three independently manufactured lots of ANSR reagents support a shelf-life of 1 year when stored at 2–8°C.

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.

SAS™ Molecular tests Escherichia coli O157 Detection Kit

2014 ◽  
Vol 97 (3) ◽  
pp. 798-807 ◽  
Author(s):  
Chandra Bapanpally ◽  
Laura Montier ◽  
Shah Khan ◽  
Akif Kasra ◽  
Sharon L Brunelle
Keyword(s):  
Escherichia Coli ◽  
Hold Time ◽  
Method Comparison ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Test Portion ◽  
Method Performance ◽  
E Coli ◽  
Molecular Tests ◽  
The U.S

Abstract The SAS™ Molecular tests Escherichia coli O157 Detection method, a loop-mediated isothermal amplification method, performed as well as or better than the U.S. Department of Agriculture, Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, bagged mixed lettuce, and fresh spinach. Ground beef (30% fat, 25 g test portion) was validated for 7–8 h enrichment, leafy greens were validated in a 6–7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16–20 h enrichment. The method performance for meat and leafy green matrixes was also shown to be acceptable under conditions of co-enrichment with Salmonella. Thus, after a short co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. The SAS Molecular tests Salmonella Detection Kit was validated using the same test portions as for the SAS Molecular tests E. coli O157 Detection Kit and those results are presented in a separate report. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 E. coli O157 strains, including H7 and non-motile strains, and 30 non-E. coli O157 strains examined. Finally, the method was shown to be robust when variations to DNA extract hold time and DNA volume were varied. The method comparison and robustness data suggest a full 7 h enrichment time should be used for 25 g ground beef test portions.

Validation of the ANSR®E. coli O157:H7 Method for Detection of E. coli O157:H7

2016 ◽  
Vol 99 (3) ◽  
pp. 705-716 ◽  
Author(s):  
Ryan Viator ◽  
Susan Alles ◽  
Quynh-Nhi Le ◽  
Edan Hosking ◽  
Evan Meister ◽  
...  
Keyword(s):  
Target Genes ◽  
Ground Beef ◽  
Reference Method ◽  
Single Step ◽  
Fluorescence Detector ◽  
Method Performance ◽  
E Coli ◽  
Reference Methods ◽  
Inspection Service ◽  
The U.S

Abstract A performance validation of the ANSR® for E. coli O157:H7 method was conducted in selected food matrixes. This assay uses selective nicking enzyme amplification technology to amplify target genes. Samples are enriched for 12–24 h and then lysed. The assay is completed within 40 min using real-time detection in a combination incubator/fluorescence detector and software. When 44 distinct strains of Escherichia coli O157:H7 and 6 strains of E. coli O157:NM were tested for inclusivity, all 50 strains produced positive results. In exclusivity testing, 57 strains representing 33 species of closely related Gram-negative bacteria belonging to the Enterobacteriaceae family, including 11 non-H7 O157 strains and shiga toxin-producing E. coli other than O157:H7, were evaluated. All 57 nontarget strains generated negative ANSR assay results. Using 80% lean ground beef and beef trim (approximately 20% fat), ANSR method performance was compared to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure. ANSR performance with baby spinach and sprout irrigation water was measured against the U.S. Food and Drug Administration Bacteriological Analytical Manual reference method. ANSR method performance was not statistically different to that of the reference methods using two different enrichment options. For ground beef and beef trim, the standard enrichment in modified Tryptone Soya Broth can be analyzed using the ANSR assay with a 1:10 dilution of the enrichment in phosphate-buffered saline and produces equivalent results to the reference method. Additionally, in most matrixes tested (exception is spinach which required 24 h enrichment) the assay offers great efficiency and flexibility over the reference method with a 12–24 h single-step enrichment. Equivalent results were observed at both time points (12 and 24 h) to reference methods. Small changes to the assay parameters minimally affected ANSR method performance. Finally, accelerated stability results from three independently manufactured lots support a shelf-life of 6 months when stored at 4°C.

scholarly journals Validation of iQ-Check E. coli O157:H7 Real-Time PCR Test Kit for Detection of Escherichia coli O157:H7 in Selected Foods

2009 ◽  
Vol 92 (4) ◽  
pp. 1095-1104 ◽  
Author(s):  
Wendy F Lauer ◽  
Sylvie Tymciu ◽  
Caroline D Sidi ◽  
Pierre Sonigo
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Ground Beef ◽  
Reference Method ◽  
Target Sequence ◽  
Apple Cider ◽  
E Coli ◽  
Test Kit ◽  
Significant Difference ◽  
The U.S

Abstract iQ-Check E. coli O157:H7 (Bio-Rad Laboratories, Hercules, CA) is a real-time PCR kit for detection of E. coli O157:H7 from selected foods. Specific fluorescent oligonucleotide probes are used to detect target DNA during the amplification, by hybridizing to the amplicons. These fluorescent probes are linked to a fluorophore which fluoresces only when hybridized to the target sequence. Three foods (ground beef, apple cider, fresh spinach) were selected to compare the performance of iQ-Check E. coli O157:H7 to the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook (MLG) reference method for ground beef and the U.S. Food and Drug Administration/Bacteriological Analytical Manual reference method for apple cider and fresh spinach. Three protocols were tested in this study: a shortened 8 h primary enrichment in buffered peptone water (BPW), a 24 h enrichment in BPW, and an enrichment in appropriate reference method enrichment broth. The iQ-Check E. coli O157:H7 method was able to identify more true/confirmed positive samples than the reference method. Inclusivity and exclusivity rates of the method were 100. iQ-Check E. coli O157:H7 performed as expected when minor procedural variations were introduced, validating the ruggedness of the method. There was no significant difference observed in performance over the shelf life of the kit.

scholarly journals Sensitivity and Specificity of the Test Kit BAX® for Screening/ E. coli O157:H7 in Ground Beef: Independent Laboratory Study

2000 ◽  
Vol 83 (6) ◽  
pp. 1349-1356 ◽  
Author(s):  
Alan M Hochberg ◽  
Paul N M Gerhardt ◽  
Thoa K Cao ◽  
Wilfredo Ocasio ◽  
W Mark Barbour ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Laboratory Study ◽  
Ground Beef ◽  
Culture Method ◽  
E Coli ◽  
Independent Laboratory ◽  
Test Kit ◽  
And Performance ◽  
Food Laboratory ◽  
Product Claims

Abstract An independent laboratory study of the BAX® for Screening/E. coli O157:H7 kit was conducted at the National Food Laboratory, Inc., Dublin, CA, to complete AOAC® Performance Tested MethodSM certification. The BAX system kit was compared with the BAM culture method and a modified BAM culture method for detection of E. coli O157:H7 in ground beef. The BAX system kit detected the target organism at levels approximately 10-fold lower than those that gave positive BAM results. This study validated product claims, and Performance Tested Method status was granted.

scholarly journals Reveal 8-Hour Test System for Detection of Escherichia coli O157:H7 in Raw Ground Beef, Raw Beef Cubes, and Iceberg Lettuce Rinse: Collaborative Study

2001 ◽  
Vol 84 (3) ◽  
pp. 719-736 ◽  
Author(s):  
Charles B Bird ◽  
Rebecca J Hoerner ◽  
Lawrence Restaino ◽  
G Anderson ◽  
W Birbari ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Ground Beef ◽  
Culture Method ◽  
The United States ◽  
Test System ◽  
Private Industry ◽  
E Coli ◽  
Inspection Service ◽  
High Level ◽  
The U.S

Abstract Five different food types were analyzed by the Reveal for E. coli O157:H7 8-Hour Test System (Reveal 8) and either the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) culture method or the U.S. Department of Agriculture Food Safety Inspection Service (FSIS) culture method for the presence of E. coli O157:H7. A total of 27 laboratories representing academia and private industry in the United States and Canada participated. Food types were inoculated with E. coli O157:H7 at 2 different levels: a high level where predominantly positive results were expected, and a low level where fractional recovery was anticipated. During this study, 1110 samples and controls were analyzed by both the Reveal 8 and by BAM or FSIS by each of the collaborators (2220 samples in total). For each set of samples, 740 were artificially inoculated with E. coli O157:H7, and 370 were uninoculated controls. The Reveal 8 detected 528 presumptive positives of which 487 were confirmed positive by the BAM culture method. In comparison, BAM and FSIS detected 489 of the 740 artificially contaminated samples as positive. In an additional in-house study performed only on chilled and frozen raw ground beef, 240 artificially inoculated samples were analyzed by both the Reveal 8 and by FSIS. The Reveal 8 detected and confirmed 104 samples as positive compared to 79 confirmed positive by FSIS.

scholarly journals Evaluation of the GeneQuence® DNA Hybridization Method in Conjunction with 24-Hour Enrichment Protocols for Detection of Salmonella spp. in Select Foods: Collaborative Study

2007 ◽  
Vol 90 (3) ◽  
pp. 738-755 ◽  
Author(s):  
Mark A Mozola ◽  
Xuan Peng ◽  
Michael Wendorf ◽  
S Alles ◽  
L Artiga ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Ground Beef ◽  
Pet Food ◽  
Salmonella Spp ◽  
Milk Chocolate ◽  
Method Performance ◽  
Significant Difference ◽  
Chi Square Analysis ◽  
Whole Egg ◽  
The U.S

Abstract A multilaboratory study was conducted to compare performance of the GeneQuence® DNA hybridization (DNAH) method incorporating new 24 h enrichment protocols and reference culture procedures for detection of Salmonella spp. in select foods. Six food types (raw ground turkey, raw ground beef, dried whole egg, milk chocolate, walnuts, and dry pet food) were tested by the DNAH method and by the culture methods of either the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) or the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM). Fifteen laboratories participated in the study. Four of the foods tested (raw ground turkey, dried whole egg, milk chocolate, and dry pet food), showed no statistically significant differences in performance between the DNAH method and the reference procedure as determined by Chi square analysis. Sensitivity rates for the DNAH method ranged from 92 to 100. The DNAH method, with the specific enrichment protocol evaluated, was found to be ineffective for detection of Salmonella spp. in walnuts. For raw ground beef, results from one trial showed a statistically significant difference in performance, with more positives obtained by the reference method. However, evidence suggests that the difference in the number of positives was likely due to lack of homogeneity of the test samples rather than to DNAH method performance.

Reveal®E. coli 2.0 Method for Detection of Escherichia coli O157:H7 in Raw Beef

2011 ◽  
Vol 94 (6) ◽  
pp. 1835-1845 ◽  
Author(s):  
Rebecca Hoerner ◽  
Jill Feldpausch ◽  
R Lucas Gray ◽  
Stephanie Curry ◽  
Paul Lewis ◽  
...  
Keyword(s):  
Test Performance ◽  
Test Procedure ◽  
Ground Beef ◽  
Test Sample ◽  
Sample Volume ◽  
Method Performance ◽  
E Coli ◽  
Test Specificity ◽  
Inspection Service ◽  
Positive Results

Abstract Reveal®E. coli 2.0 is a new lateral-flow immunodiagnostic test for detection of E. coli O157:H7 and O157:NM in raw beef trim and ground beef. Compared with the original Reveal E. coli O157:H7 assay, the new test utilizes a unique antibody combination resulting in improved test specificity. The device architecture and test procedure have also been modified, and a single enrichment protocol was developed which allows the test to be performed at any point during an enrichment period of 12 to 20 h. Results of inclusivity and exclusivity testing showed that the test is specific for E. coli serotypes O157:H7 and O157:NM, with the exception of two strains of O157:H38 and one strain of O157:H43 which produced positive reactions. In internal and independent laboratory trials comparing the Reveal 2.0 method to the U.S. Department of Agriculture–Food Safety and Inspection Service reference culture procedure for detection of E. coli O157:H7 in 65 and 375 g raw beef trim and ground beef samples, there were no statistically significant differences in method performance with the exception of a single internal trial with 375 g ground beef samples in which the Reveal method produced significantly more positive results. There were no unconfirmed positive results by the Reveal assay, for specificity of 100%. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device incubation time or temperature. However, addition of the promoter reagent to the test sample prior to introducing the test device is essential to proper test performance.

scholarly journals Genetics-Based Methods for Detection of Salmonella spp. in Foods

2006 ◽  
Vol 89 (2) ◽  
pp. 517-529 ◽  
Author(s):  
Mark A Mozola
Keyword(s):  
Foodborne Pathogen ◽  
Dna Probe ◽  
Nucleic Acid Amplification ◽  
Analytical Sensitivity ◽  
Salmonella Spp ◽  
Method Performance ◽  
Methods Development ◽  
Nucleic Acid Amplification Technology ◽  
Pathogen Testing ◽  
Sensitivity Specificity

Abstract Genetic methods are now at the forefront of foodborne pathogen testing. The sensitivity, specificity, and inclusivity advantages offered by deoxyribonucleic acid (DNA) probe technology have driven an intense effort in methods development over the past 20 years. DNA probe-based methods for Salmonella spp. and other pathogens have progressed from time-consuming procedures involving the use of radioisotopes to simple, high throughput, automated assays. The analytical sensitivity of nucleic acid amplification technology has facilitated a reduction in analysis time by allowing enriched samples to be tested for previously undetectable quantities of analyte. This article will trace the evolution of the development of genetic methods for detection of Salmonella in foods, review the basic assay formats and their advantages and limitations, and discuss method performance characteristics and considerations for selection of methods.

SAS™ Molecular Tests Salmonella Detection Kit

2014 ◽  
Vol 97 (3) ◽  
pp. 808-819 ◽  
Author(s):  
Chandra Bapanpally ◽  
Laura Montier ◽  
Shah Khan ◽  
Akif Kasra ◽  
Sharon L Brunelle
Keyword(s):  
Hold Time ◽  
Ground Beef ◽  
Department Of Agriculture ◽  
Test Portion ◽  
Method Performance ◽  
Molecular Tests ◽  
Amplification Method ◽  
Chicken Carcass ◽  
Inspection Service ◽  
The U.S

Abstract The SAS™ Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6–7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16–20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli O157. Thus, after a short 6–7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non- Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied.

Sign in / Sign up

Export Citation Format

Share Document