Deoxyribonucleic Acid Hybridization Method for the Detection of Listeria in Dairy Products, Seafoods, and Meats: Collaborative Study

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.

1994 ◽  
Vol 77 (6) ◽  
pp. 1472-1489 ◽  
Author(s):  
Michael S Curiale ◽  
Wendy Lepper ◽  
Barbara Robison

Abstract A collaborative study was conducted to evaluate Listeria-TekTM, an enzyme-linked immunosorbent assay (ELISA) for detection of Listeria monocytogenes and other Listeria spp. in foods. The present ELISA method was compared to the U.S. Food and Drug Administration culture method for detection of L. monocytogenes in dairy products and seafoods and to the U.S. Department of Agriculture Food Safety and Inspection Service method for detection of L. monocytogenes in meats. Replicate samples of 6 food types (frankfurters, roast beef, Brie cheese, 2% milk, raw shrimp, and crab meat) inoculated with L. monocytogenes and uninoculated control samples were analyzed by the collaborators. L. monocytogenes was identified in 593 samples by the ELISA method and in 574 samples using culture procedures. Identical results were obtained for 506 positive samples and 419 negative samples using the ELISA and culture methods for an overall agreement rate of 85.6%. The enzyme-linked immunoassay for detection of L. monocytogenes in dairy, seafood, and meat products has been adopted first action by AOAC INTERNATIONAL.


2001 ◽  
Vol 84 (3) ◽  
pp. 719-736 ◽  
Author(s):  
Charles B Bird ◽  
Rebecca J Hoerner ◽  
Lawrence Restaino ◽  
G Anderson ◽  
W Birbari ◽  
...  

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.


2002 ◽  
Vol 85 (5) ◽  
pp. 1029-1036 ◽  
Author(s):  
Philip T Feldsine ◽  
David E Kerr ◽  
Stephanie C Leung ◽  
Andrew H Lienau ◽  
Ruth F Moser ◽  
...  

Abstract AOAC Official Method 996.09, Visual Immunoprecipitate Assay (VIP®) for Escherichia coli O157:H7, was modified to incorporate a new enrichment protocol using BioControl EHEC8™ medium for testing raw and cooked beef. Foods were tested by VIP assay and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) enrichment procedure and the FDA Bacteriological Analytical Manual (BAM) isolation and confirmation techniques. A total of 15 collaborators participated. Raw and cooked ground beef were inoculated with E. coli O157:H7 at 2 different levels: a high level, where predominantly positive results were expect d, and a low level where fractional recovery was anticipated. Collaborators tested 396 test portions and controls by both methods, for a total of 792 test portions. Of the 396 paired test portions, 75 were positive and 230 were negative by both the VIP and culture methods. Eleven test portions were presumptively positive by VIP and could not be confirmed culturally; 32 were negative by VIP, but confirmed positive by culture; and 65 were negative by the culture method, but confirmed positive by the VIP method. There was no statistical difference between results obtained with the VIP for EHEC 8 h method and the culture method except for cooked beef, where the VIP had significantly higher recovery for one inoculation level.


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.


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.


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.


2007 ◽  
Vol 90 (3) ◽  
pp. 725-737 ◽  
Author(s):  
Susan Alles ◽  
Xuan Peng ◽  
Michael Wendorf ◽  
Mark Mozola

Abstract New enrichment protocols are described for use with a DNA hybridization (DNAH) method for detection of Salmonella spp. in select foods. GeneQuence® Salmonella, in its original version, utilized a 3-stage enrichment of minimum 42 h duration. New 2-stage procedures of 2428 h duration are described for raw poultry, raw beef, pasteurized egg products, milk chocolate, and dry pet food. In the validation study described here, a total of 345 samples were tested by the abbreviated DNAH method in parallel with either the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM) or U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) reference culture procedures. Results showed an overall sensitivity for the DNAH method of 97.1% (false-negative rate 2.9%). There were no false-positive results by the DNAH method; therefore the specificity was 100%. Overall agreement between the DNAH and reference culture methods was 98.5%. There were no significant differences in performance between the DNAH and reference methods for any of the foods tested as determined by Chi-square analysis. It is recommended that the DNAH method be subjected to AOAC collaborative study.


1992 ◽  
Vol 75 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Anna Westöö ◽  
Mats Peterz

Abstract Eleven Nordic laboratories participated in a collaborative study on qualitative methods for the detection of Listeria monocytogenes in foods. Two enrichment methods (U.S. Department of Agriculture, Food Safety and Inspection Service method for meat, and modified U.S. Food and Drug Administration/International Dairy Federation method for dairy products) and 2 agar media (lithium chloride-phenylethanol-moxalactam (LPM) and Oxford agar) were compared. The effect of treatment of the enriched culture with KOH before plating was also studied. Food samples, blue and white mold cheese and canned corned beef, were Inoculated with 3 levels of L. monocytogenes. Beef was also Inoculated with a microbial flora derived from raw meat. The recoveries of L. monocytogenes using the 2 enrichment methods did not differ significantly. The Oxford agar was superior to the LPM agar. KOH treatment of the enriched culture did not significantly increase the detection rate of the organism. For cheese, the detection level of the methods was below 0.2 cfu L. monocytogenes/g and for meat, the detection level was below 5 cfu L monocytogenes/g.


1996 ◽  
Vol 79 (5) ◽  
pp. 1083-1094 ◽  
Author(s):  
Michael T Knight ◽  
Melissa C Newman ◽  
M Joseph Benzinger ◽  
James R Agin ◽  
Megan Ash ◽  
...  

Abstract A collaborative study involving 26 laboratories and 5 food types was performed to compare the TECRA Listeria Visual Immunoassay (TLVIA) with standard culture methods. Three foods (lettuce, ice cream, and fish fillets), under the jurisdiction of the U.S. Food and Drug Administration, and 2 foods (cooked chicken and cooked ground turkey), under the jurisdiction of the U.S. Department of Agriculture, were used to determine the effectiveness of the TLVIA. Of the 900 samples tested, 300 were inoculated with low levels (1-5 cells/25 g) of Listeria spp. and 300 were inoculated with high levels of Listeria spp. (10-50 cells/25 g). Method agreement between the conventional culture methods and TLVIA (visual) was 94.7%. Method agreement between the conventional culture methods and TLVIA (reader) was 93.6%. The colorimetric polyclonal enzyme immunoassay (TLVIA) for detection of Listeria in foods has been adopted first action by AOAC INTERNATIONAL.


2016 ◽  
Vol 79 (8) ◽  
pp. 1341-1347 ◽  
Author(s):  
JOSEPH M. BOSILEVAC ◽  
RONG WANG ◽  
BRANDON E. LUEDTKE ◽  
TOMMY L. WHEELER ◽  
MOHAMMAD KOOHMARAIE

ABSTRACT During site visits of veal processors, the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS) has reported processing deficiencies that likely contribute to increased levels of veal contamination. Here, we report the results of measuring aerobic plate count bacteria (APC), Enterobacteriaceae, coliforms (CF), and Escherichia coli during eight sample collections at five veal processors to assess contamination during the harvest of bob veal and formula-fed veal before (n = 5 plants) and after (n = 3 plants) changes to interventions and processing practices. Hides of veal calves at each plant had mean log CFU/100 cm2 APC, Enterobacteriaceae, CF, and E. coli of 6.02 to 8.07, 2.95 to 5.24, 3.28 to 5.83, and 3.08 to 5.59, respectively. Preintervention carcasses had mean log CFU/100 cm2 APC, Enterobacteriaceae, CF, and E. coli of 3.08 to 5.22, 1.16 to 3.47, 0.21 to 3.06, and −0.07 to 3.10, respectively, before and 2.72 to 4.50, 0.99 to 2.76, 0.69 to 2.26, and 0.33 to 2.12, respectively, after changes were made to improve sanitary dressing procedures. Final veal carcasses had mean log CFU/100 cm2 APC, Enterobacteriaceae, CF, and E. coli of 0.36 to 2.84, −0.21 to 1.59, −0.23 to 1.59, and −0.38 to 1.45 before and 0.44 to 2.64, −0.16 to 1.33, −0.42 to 1.20, and −0.48 to 1.09 after changes were made to improve carcass-directed interventions. Whereas the improved dressing procedures resulted in improved carcass cleanliness, the changes to carcass-directed interventions were less successful, and veal processors are urged to use techniques that ensure uniform and consistent delivery of antimicrobials to carcasses. Analysis of results comparing bob veal to formula-fed veal found bob veal hides, preintervention carcasses, and final carcasses to have increased (P < 0.05) APC, Enterobacteriaceae, CF, and E. coli (with the exception of hide Enterobacteriaceae; P > 0.05) relative to formula fed veal. When both veal categories were harvested at the same plant on the same day, similar results were observed. Since identification by FSIS, the control of contamination during veal processing has started to improve, but challenges still persist.


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