Roka Listeria Detection Method Using Transcription Mediated Amplification to Detect Listeria Species in Select Foods and Surfaces

2012 ◽  
Vol 95 (6) ◽  
pp. 1672-1688 ◽  
Author(s):  
Hua Yang ◽  
Shannon Kaplan ◽  
Michael Reshatoff ◽  
Ernie Hu ◽  
Alexis Zukowski ◽  
...  

Abstract The Roka Listeria Detection Assay was compared to the reference culture methods for nine select foods and three select surfaces. The Roka method used Half-Fraser Broth for enrichment at 35 ± 2°C for 24–28 h. Comparison of Roka's method to reference methods requires an unpaired approach. Each method had a total of 545 samples inoculated with a Listeria strain. Each food and surface was inoculated with a different strain of Listeria at two different levels per method. For the dairy products (Brie cheese, whole milk, and ice cream), our method was compared to AOAC Official MethodSM993.12. For the ready-to-eat meats (deli chicken, cured ham, chicken salad, and hot dogs) and environmental surfaces (sealed concrete, stainless steel, and plastic), these samples were compared to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG) method MLG 8.07. Cold-smoked salmon and romaine lettuce were compared to the U.S. Food and Drug Administration/Bacteriological Analytical Manual, Chapter 10 (FDA/BAM) method. Roka's method had 358 positives out of 545 total inoculated samples compared to 332 positive for the reference methods. Overall the probability of detection analysis of the results showed better or equivalent performance compared to the reference methods.

2013 ◽  
Vol 96 (4) ◽  
pp. 822-841 ◽  
Author(s):  
William Kwong ◽  
Kristin Livezey ◽  
Michael Reshatoff ◽  
Steve Vaughn ◽  
Anna Freed ◽  
...  

Abstract The Atlas™ Salmonella detection assay was compared to the reference culture methods for 12 foods and three surfaces. Comparison of the Atlas method to the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA/BAM) and U.S. Department of Agriculture-Food Safety and Inspection Service/Microbiology Laboratory Guidebook (USDA-FSIS/MLG) reference methods required an unpaired approach. Each method had a total of 320 samples inoculated with an S. enterica strain. Each food and surface was inoculated with a different strain of S. enterica at two different levels/method. Meat and egg products were compared to the USDA-FSIS/MLG 4.05 method. All other foods were compared to the FDA/BAM-5 method. The Atlas method had 148 positives out of 320 total inoculated samples, compared to 119 positives for the reference methods. Overall, the probability of detection analysis of the results showed equivalent or better performance by the Atlas Salmonella detection method compared to the reference methods. The Atlas Salmonella detection assay detected all 100 inclusive organisms and none of the 30 exclusive organisms. The lot-to-lot and kit stability studies showed no statistical differences between lots or over the term of the shelf-life. Instrument-to-instrument testing showed no statistical difference between instruments. Finally, the robustness study showed no difference when the sample volume added to the Atlas Salmonella detection assay varied by 10%, storage time was extended up to 5 days before analysis, or enrichment times were varied from 12 to 24 h.


2018 ◽  
Vol 101 (5) ◽  
pp. 1490-1507
Author(s):  
Gregory Juck ◽  
Verapaz Gonzalez ◽  
Ann-Christine Olsson Allen ◽  
Meredith Sutzko ◽  
Kody Seward ◽  
...  

Abstract The Romer Labs RapidChek®Listeria monocytogenes test system (Performance Tested Method 011805) was validated against the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook (USDA-FSIS/MLG), U.S. Food and Drug Association Bacteriological Analytical Manual (FDA/BAM), and AOAC Official Methods of Analysis (AOAC/OMA) cultural reference methods for the detection of L. monocytogenes on selected foods including hot dogs, frozen cooked breaded chicken, frozen cooked shrimp, cured ham, and ice cream, and environmental surfaces including stainless steel and plastic in an unpaired study design. The RapidChek method uses a proprietary enrichment media system, a 44–48 h enrichment at 30 ± 1°C, and detects L. monocytogenes on an immunochromatographic lateral flow device within 10 min. Different L. monocytogenes strains were used to spike each of the matrixes. Samples were confirmed based on the reference method confirmations and an alternate confirmation method. A total of 140 low-level spiked samples were tested by the RapidChek method after enrichment for 44–48 h in parallel with the cultural reference method. There were 88 RapidChek presumptive positives. One of the presumptive positives was not confirmed culturally. Additionally, one of the culturally confirmed samples did not exhibit a presumptive positive. No difference between the alternate confirmation method and reference confirmation method was observed. The respective cultural reference methods (USDA-FSIS/MLG, FDA/BAM, and AOAC/OMA) produced a total of 63 confirmed positive results. Nonspiked samples from all foods were reported as negative for L. monocytogenes by all methods. Probability of detection analysis demonstrated no significant differences in the number of positive samples detected by the RapidChek method and the respective cultural reference method.


2019 ◽  
Vol 102 (3) ◽  
pp. 815-827
Author(s):  
David E Kerr ◽  
George Shen ◽  
Andrew H Lienau ◽  
Mandeep Kaur ◽  
Amy L Immermann ◽  
...  

Abstract Background: VIP® Gold for Salmonella is a lateral flow immunodetection device that was validated by AOAC in 1999 as Official Method of Analysis 999.09. It was improved upon in 2009 by introducing gold colloid as the detection method. Objective: A simple next-day enrichment protocol using modified enterohemorrhagic Escherichia coli media was developed for the VIP Gold for Salmonella to improve the time-to-results and laboratory work flow. Methods: We tested 128 Salmonella strains, representing all serotypes from A to Z and 51 to 66 as well as 50 non-Salmonella strains for inclusivity/exclusivity. Performance of the VIP using the new enrichment protocol was compared with the U.S. Department of Agriculture (USDA) Microbiology Laboratory Guidebook reference culture procedure for the detection of Salmonella in ready-to-eat poultry, roast beef, and chicken carcass rinsate. VIP performance was also compared with the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) for the detection of Salmonella from raw spinach, raw almonds, raw pasta, and environmental surfaces (stainless steel, rubber, and plastic). Results: The VIP detected all 128 of Salmonella strains and none of the 50 non-Salmonella strains. There was no statistically significant difference in the numbers of positive results with VIP Gold for Salmonella protocol compared with appropriate USDA-Food Safety and Inspection Service or FDA-BAM reference methods for any of these matrixes. Conclusions: This new enrichment protocol has met all the requirements to be approved as a Performance Tested MethodSM. Highlights: The new enrichment protocol will improve the time-to-results and allow quicker decisions about the contamination of food products.


2018 ◽  
Vol 101 (2) ◽  
pp. 562-576
Author(s):  
Brett Maroni ◽  
Tucker Lopez ◽  
Cambria Neal ◽  
Sarah Verver ◽  
Celina Puente ◽  
...  

Abstract Two candidate method modifications for the Atlas Listeria Environmental LE Detection Assay were compared with the U.S. Department of Agriculture (USDA)-Food Safety and Inspection Service Microbiology Laboratory Guidebook 8.09 (MLG 8.09) method for detection of Listeria spp. on stainless steel, polyvinyl chloride (PVC), and sealed concrete surfaces. For LE candidate method 1, samples were enriched in FoodChek Actero Listeria Enrichment Media [ALEM; Performance Tested MethodSM (PTM) 111201] at 35 ± 2°C for 18 to 24 h and evaluated for a range of analytical sample volumes. For LE candidate method 2, the current Roka PTM using 90 mL of Half-Fraser broth for enrichment at 35 ± 2°C was evaluated at 24 h with a reduced sample volume. These comparisons were made in multiple studies across the three environmental surfaces. Within each method and study, a total of 5 samples were uninoculated, 20 samples were inoculated with Listeria spp. at a low level to target fractional positivity, and 5 samples were inoculated with Listeria spp. at a high level to approach a probability of detection of 1. Inclusivity and exclusivity studies were also conducted for the LE method in combination with Half-Fraser and ALEM. The Atlas Listeria Environmental LE Detection Assay detected all 50 inclusive organisms, including 25 strains of L. monocytogenes and 5 strains of each of the other five common species of Listeria (L. innocua, L. welshimeri, L. ivanovii, L. seeligeri, and L. grayi) and none of the 30 exclusive organisms across all media and with both 200 and 2000 µL sample volumes. For the LE candidate method 1 studies, no significant differences were observed within the Roka ALEM method at 18, 20, or 24 h and for both the 200 and 2000 µL sample volumes as compared with the paired culture outcome. However, the ALEM method performed significantly better as compared with the unpaired reference method for sealed concrete and stainless steel. For the LE candidate method 2 studies, no significant differences were observed within the Roka HF method at 24 h for the 200 and 2000 µL samples as compared with the paired culture outcomes and unpaired reference method outcomes across the surfaces. The independent laboratory studies observed no significant differences in performance between the USDA/MLG 8.09 reference method and candidate methods 1 or 2, respectively, across the evaluated parameters. Overall, the candidate method 1 modification parameters and candidate method 2 sample parameters for the Atlas Listeria Environmental LE Detection Assay were statistically equivalent to or better than the reference method for detection of Listeria spp. on stainless steel, PVC, and sealed concrete surfaces, providing greater flexibility in method application for end users.


2018 ◽  
Vol 101 (4) ◽  
pp. 1059-1100 ◽  
Author(s):  
Emma Scopes ◽  
Jessica Screen ◽  
Katharine Evans ◽  
David Crabtree ◽  
Annette Hughes ◽  
...  

Abstract The Thermo Scientific RapidFinder™ Salmonella Species, Typhimurium, and Enteritidis Multiplex PCR Kit (candidate method) is a real-time PCR assay for the detection and differentiation of Salmonella spp., and the serovars S. Typhimurium, and S. Enteritidis from poultry, pork, and environmental samples. The method was validated in comparison to the U.S. Department of Agriculture Food Safety and Inspection Service and the U.S. Food and Drug Administration reference methods. Thermo Fisher Scientific (Basingstoke, United Kingdom) tested all matrixes. In addition, two matrixes were analyzed independently by Q Laboratories, Inc. (Cincinnati, OH). Few statistically significant differences were found between the candidate and reference methods when analyzed by probability of detection. When differences were observed, these were in favor of the candidate method. All 200 inclusivity strains and none of the 45 exclusivity strains were detected, which demonstrated that the RapidFinder Salmonella Species, Typhimurium, and Enteritidis Multiplex PCR Kit was able to detect all the major groups of Salmonella, the less common subspecies of S. enterica, and the rarely encountered S. bongori. None of the exclusivity isolates analyzed were detected. Robustness testing demonstrated that the assay gave reliable performance, with specific method deviations outside the recommended parameters. Accelerated stability testing was conducted, validating the assay shelf life.


2016 ◽  
Vol 99 (4) ◽  
pp. 1017-1024 ◽  
Author(s):  
Mark Mozola ◽  
Preetha Biswas ◽  
Ryan Viator ◽  
Emily Feldpausch ◽  
Debra Foti ◽  
...  

Abstract A study was conducted to assess the performance of the Reveal® 2.0 Group D1 Salmonella lateral flow immunoassay for use in detection of Salmonella Enteritidis (SE) in raw shell eggs and poultry-associated matrixes, including chicken carcass rinse and poultry feed. In inclusivity testing, the Reveal 2.0 test detected all 37 strains of SE tested. The test also detected all but one of 18 non-Enteritidis somatic group D1 Salmonella serovars examined. In exclusivity testing, none of 42 strains tested was detected. The exclusivity panel included Salmonella strains of somatic groups other than D1, as well as strains of other genera of Gram-negative bacteria. In matrix testing, performance of the Reveal 2.0 test was compared to that of the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure for chicken carcass rinse and to that of the U.S. Food and Drug Administration Bacteriological Analytical Manual for raw shell eggs and poultry feed. For all matrixes evaluated, there were no significant differences in the ability to detect SE when comparing the Reveal 2.0 method and the appropriate reference culture procedure as determined by probability of detection statistical analysis. The ability of the Reveal 2.0 test to withstand modest perturbations to normal operating parameters was examined in robustness experiments. Results showed that the test can withstand deviations in up to three operating parameters simultaneously without significantly affecting performance. Real-time stability testing of multiple lots of Reveal 2.0 devices established the shelf life of the test device at 16 months postmanufacture.


2009 ◽  
Vol 92 (4) ◽  
pp. 1105-1117 ◽  
Author(s):  
Vicki Ritter ◽  
Susan Kircher ◽  
Krista Sturm ◽  
Patty Warns ◽  
Nancy Dick

Abstract BBL CHROMagar Listeria Media (CL) was evaluated for detection of Listeria monocytogenes in raw ground beef, smoked salmon, lettuce, and Brie cheese. The recovery of L. monocytogenes on CL was compared to the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM), U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS), AOAC, and International Organization for Standardization (ISO) reference-plated media using the recommended pre-enrichments and selective enrichments. Of the 265 food samples tested, 140 were tested using BAM, USDA, or AOAC methods and 125 were tested using ISO methods. CL produced comparable results with the reference methods on all matrixes with a sensitivity of 99.3 and a specificity of 100. No false negatives were found in testing the food matrixes. There was no statistical difference in recovery based on Chi-square analysis. Known isolates were evaluated, and CL had a sensitivity and specificity of 100. The results of this study demonstrate that CL is an effective medium for the recovery and detection of L. monocytogenes in raw ground beef, smoked salmon, lettuce, and Brie cheese using FDA BAM, USDA FSIS, AOAC, and ISO culture methods.


1994 ◽  
Vol 77 (3) ◽  
pp. 602-617 ◽  
Author(s):  
Michael S Curiale ◽  
Terri Sons ◽  
Luanne Fanning ◽  
Wendy Lepper ◽  
Dawn Mclver ◽  
...  

Abstract The method is based on the hybridization of synthetic deoxyribonucleic acid probes to ribosomal ribonucleic acid sequences unique to Listeria. This method was compared to 2 culture methods: the U.S. Food and Drug Administration method for the detection of Listeria in dairy products and sea-foods and the U.S. Department of Agriculture, Food Safety and Inspection Service method for Listeria in meats. Six food types with replicate samples containing various concentrations of Listeria were analyzed by the collaborating laboratories. Listeria was detected in 774 samples using the DNAH method and in 772 samples using a culture method. The DNAH and culture methods were in agreement for 668 samples containing Listeria and 306 samples without Listeria. The overall rate of agreement between methods was 82.3%. The method has been adopted first action by AOAC INTERNATIONAL.


2011 ◽  
Vol 94 (3) ◽  
pp. 863-871
Author(s):  
F Morgan Wallace ◽  
Dawn Fallon ◽  
Daniel DeMarco ◽  
Stephen Varkey

Abstract The new BAX® System PCR Assay for Genus Listeria 24E was evaluated for detecting Listeria spp. in frankfurters, spinach, cooked shrimp, queso fresco cheese, and on stainless steel surfaces with a single-stage enrichment in BAX System 24 Listeria Enrichment Broth (24 LEB). Method comparison studies performed on samples with low-level inoculates showed that the BAX System demonstrates a sensitivity equivalent or superior to the U.S. Food and Drug Administration's Bacteriological Analytical Manual and the U.S. Department of Agriculture-Food Safety and Inspection Service culture methods, but with a significantly shorter time to result. Tests to evaluate inclusivity and exclusivity returned no false-negative and no false-positive results on a diverse panel of isolates, and tests for lot-to-lot variability and tablet stability demonstrated consistent performance. Ruggedness studies determined that none of the factors examined, within the range of deviations from specified parameters examined, affect the performance of the assay.


2019 ◽  
Vol 102 (5) ◽  
pp. 1589-1594
Author(s):  
Brooke Roman ◽  
Mark Mozola ◽  
Robert Donofrio ◽  
Benjamin Bastin ◽  
Nicole Klass ◽  
...  

Abstract Background: Listeria Right Now™ is a novel, enrichment-free test for the detection of Listeria spp. in swab samples taken from environmental surfaces. Results are available in less than 1 h. In a previous Performance Tested MethodSM (PTM) study, the test was validated for swab samples from stainless-steel and sealed concrete surfaces. Objective: A PTM matrix extension study was conducted to validate the method for the detection of Listeria spp. in swab samples from ceramic tile, plastic, and rubber surfaces. Methods: Performance of the Listeria Right Now method was compared to that of the U.S. Food and Drug Administration Bacteriological Analytical Manual reference culture procedure for the detection of Listeria spp. in swab samples taken from inoculated ceramic tile, plastic, and rubber surfaces. Data were analyzed using a probability of detection model. Results: There were no significant differences in performance between the Listeria Right Now and reference culture methods for any of the three surfaces tested, as determined by probability of detection analysis. Conclusions: The Listeria Right Now method is an effective procedure for the detection of Listeria spp. from a variety of environmental surfaces. Highlights: Listeria Right Now provides accurate results, without enrichment, in real time. This enables food industry personnel to react swiftly to suspected Listeria contamination incidents.


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