scholarly journals Evaluation of the Assurance GDS™ for E. coli O157:H7 Method and Assurance GDS for Shigatoxin Genes Method in Selected Foods: Collaborative Study

2005 ◽  
Vol 88 (5) ◽  
pp. 1334-1348 ◽  
Author(s):  
Philip T Feldsine ◽  
Shannon T Green ◽  
Andrew H Lienau ◽  
James Stephens ◽  
Markus T Jucker ◽  
...  
Keyword(s):  
Orange Juice ◽  
Collaborative Study ◽  
Ground Beef ◽  
Culture Methods ◽  
Chi Square ◽  
E Coli ◽  
Reference Methods ◽  
Uninoculated Control ◽  
Chi Square Analysis ◽  
Better Than

Abstract A multilaboratory collaborative study was conducted to compare the Assurance GDS™ for E. coli O157:H7 method and the reference culture methods for the detection of E. coli O157:H7 in orange juice, raw ground beef, and fresh lettuce. A separate companion assay, the Assurance GDS for Shigatoxin Genes method was also evaluated with the same test portions. Fifteen laboratories participated in the study. A Chi square analysis of each of the 3 food types at the high, low, and uninoculated control levels was performed. For all foods, the Assurance GDS for E. coli O157:H7 method and the Assurance GDS for Shigatoxin Genes method were equivalent to or better than the reference methods.

scholarly journals USDA FSIS, FDA BAM, and ISO Culture Methods BD BBL CHROMagar O157 Media

2009 ◽  
Vol 92 (4) ◽  
pp. 1118-1127 ◽  
Author(s):  
Vicki Ritter ◽  
Susan Kircher ◽  
Nancy Dick
Keyword(s):  
Ground Beef ◽  
Reference Method ◽  
Food Samples ◽  
Culture Methods ◽  
Chi Square ◽  
Apple Cider ◽  
E Coli ◽  
Inspection Service ◽  
Chi Square Analysis ◽  
Method Agreement

Abstract BBL CHROMagar O157 media (CO) was evaluated for detection of Escherichia coli O157:H7 in raw ground beef and unpasteurized apple cider. The recovery of E. coli O157:H7 on CO 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), and International Organization for Standardization (ISO) reference-plated media using the recommended enrichment broths. Of the 180 food samples tested, 45 were tested using BAM, 45 using the USDA method, and 90 using the ISO method. CO produced comparable results with the reference methods on all matrixes with a sensitivity of 100 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. Method agreement for raw ground beef was 85 for the USDA FSIS method and 95 for the ISO method. Method agreement for unpasteurized apple cider was 100 for the ISO and FDA BAM methods. In all cases where method agreement was <100, CO detected more positives than the reference method media. Evaluation of known isolates on CO in inclusivity and exclusivity testing had a sensitivity and specificity of 100. The results of this study demonstrate that CO is an effective medium for the recovery and detection of E. coli O157:H7 in raw ground beef and unpasteurized apple cider using FDA BAM, USDA FSIS, and ISO methods.

scholarly journals USDA FSIS and FDA BAM Culture Methods BBL CHROMagar Salmonella Prepared Plated and Difco Dehydrated Culture Media

2009 ◽  
Vol 92 (2) ◽  
pp. 459-470 ◽  
Author(s):  
Vicki Ritter ◽  
Nancy Dick
Keyword(s):  
Culture Media ◽  
False Positive Rate ◽  
Ground Beef ◽  
Reference Method ◽  
Chi Square ◽  
Shell Eggs ◽  
Reference Methods ◽  
Raw Fish ◽  
Chi Square Analysis ◽  
The U.S

Abstract BBL and Difco CHROMagar Salmonella (CS) was evaluated internally and externally for the recovery of Salmonella in raw chicken, raw ground beef, raw fish, lettuce, and shell eggs. The raw chicken and ground beef were processed according to the U.S. Department of Agriculture, Food Safety and Inspection Service reference methods. The raw fish, lettuce, and shell eggs were processed according to the U.S. Food and Drug Administration, Bacteriological Analytical Manual procedures. Only raw chicken was found to be naturally contaminated with Salmonella; all other matrixeswere seededwith an appropriate dilution of organism to achieve fractionally positive results. Salmonella strains were permitted to equilibrate with the culture-negative matrixes for 48 h at 4C. Twenty 25 g samples of each food matrix plus 5 uninoculated samples were processed. CS prepared plates (CS PPM) and laboratory prepared plates from dehydrated culture media (CS DCM) were evaluated with the reference method media. A total of 16 positive cultures were obtained from the raw chicken samples, 17 in the raw ground beef, 18 in the raw fish and lettuce, and 11 in the shell eggs. A Chi-square analysis was performed on each of the food matrixes. BBL CS produced comparable results with the reference methods on all matrixes, resulting in a method agreement of 100 based on the Chi-square results. In testing known isolates the sensitivity and specificity was determined to be 94. Specificity improved to 98 when tetrathionate broth enrichment was used. A negative- and false-positive rate of 6 was found with known isolates. No false negatives were found in testing the food matrixes. The performance of the CS prepared plate and laboratory prepared plate was identical.

scholarly journals USDA FSIS, FDA BAM, AOAC, and ISO Culture Methods BD BBL CHROMagar Listeria Media

2009 ◽  
Vol 92 (4) ◽  
pp. 1105-1117 ◽  
Author(s):  
Vicki Ritter ◽  
Susan Kircher ◽  
Krista Sturm ◽  
Patty Warns ◽  
Nancy Dick
Keyword(s):  
Ground Beef ◽  
Food Samples ◽  
International Organization ◽  
Culture Methods ◽  
Department Of Agriculture ◽  
False Negatives ◽  
Chi Square ◽  
Smoked Salmon ◽  
Inspection Service ◽  
Chi Square Analysis

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.

scholarly journals Evaluation of the BAX® System for Detection of Listeria monocytogenes in Foods: Collaborative Study

2004 ◽  
Vol 87 (2) ◽  
pp. 395-410 ◽  
Author(s):  
Karen Silbernagel ◽  
Robert Jechorek ◽  
W Mark Barbour ◽  
Peter Mrozinski ◽  
W Alejo ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Collaborative Study ◽  
Food Type ◽  
Chi Square ◽  
Cultural Methods ◽  
Smoked Salmon ◽  
Soft Cheese ◽  
Chi Square Analysis ◽  
Type 3 ◽  
Better Than

Abstract A multilaboratory study was conducted to compare the automated BAX® system and the standard cultural methods for detection of Listeria monocytogenes in foods. Six food types (frankfurters, soft cheese, smoked salmon, raw, ground beef, fresh radishes, and frozen peas) were analyzed by each method. For each food type, 3 inoculation levels were tested: high (average of 2 CFU/g), low (average of 0.2 CFU/g) and uninoculated controls. A total of 25 laboratories representing government and industry participated. Of the 2335 samples analyzed, 1109 were positive by the BAX system and 1115 were positive by the standard method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, except radishes, the BAX system performed as well as or better than the standard reference methods based on the Chi square results.

scholarly journals Two-Day Hydrophobic Grid Membrane Filter Method for Yeast and Mold Enumeration in Foods Using YM-11 Agar: Collaborative Study

1996 ◽  
Vol 79 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Phyllis Entis ◽  
A Athar ◽  
M Ballenger ◽  
M S Bendeck ◽  
W Birbari ◽  
...  
Keyword(s):  
Orange Juice ◽  
Membrane Filter ◽  
Collaborative Study ◽  
Ground Beef ◽  
Reference Method ◽  
Test Method ◽  
Filter Method ◽  
Garlic Powder ◽  
Reference Methods ◽  
Membrane Filter Method

Abstract Twenty laboratories participated in a collaborative study to validate a 2-day hydrophobic grid membrane filter method using YM-11 agar for enumeration of yeast and mold in foods. Six naturally contaminated food products were included in the study: garlic powder, raw ground beef, walnuts, flour/meal, orange juice, and yogurt. The test method produced significantly higher results than the 5-day pour plate reference method for orange juice and significantly lower, though numerically similar, results for walnuts and yogurt. Differences between the test and reference methods were not significant for garlic powder, raw ground beef, or flour/meal. Repeatability and reproducibility were similar for both the test and reference methods in all cases. The hydrophobic grid membrane filter method for enumeration of yeast and mold in foods has been adopted by AOAC INTERNATIONAL.

scholarly journals Precollaborative Study of the GeneQuence® Salmonella Assay Using 24-Hour Enrichment Protocols for Detection of Salmonella spp. in Select Foods

2007 ◽  
Vol 90 (3) ◽  
pp. 725-737 ◽  
Author(s):  
Susan Alles ◽  
Xuan Peng ◽  
Michael Wendorf ◽  
Mark Mozola
Keyword(s):  
Collaborative Study ◽  
False Negative ◽  
False Negative Rate ◽  
Salmonella Spp ◽  
Culture Methods ◽  
Department Of Agriculture ◽  
Chi Square ◽  
Salmonella Assay ◽  
Inspection Service ◽  
Chi Square Analysis

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.

Validation of the Applied Biosystems MicroSEQ® Real-Time PCR System for Detection of E. coli O157:H7 in Food

2012 ◽  
Vol 95 (5) ◽  
pp. 1495-1504 ◽  
Author(s):  
Lily Y Wong ◽  
Yanxiang Cao ◽  
Priya Balachandran ◽  
Patrick Zoder ◽  
Manohar R Furtado ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Real Time ◽  
Real Time Pcr ◽  
Ground Beef ◽  
Reference Method ◽  
Test Method ◽  
Acid Extraction ◽  
Culture Methods ◽  
Chi Square ◽  
E Coli

Abstract Modern molecular methods offer the advantages of simplicity and short time-to-results compared to traditional culture methods. We describe the validation of a new Real-Time PCR method to detect E. coli O157:H7 in five food matrixes. The complete system consists of the MicroSEQ®E. coli O157:H7 Detection Kit, sample preparation (two sample preparation methods, the PrepSEQ® Nucleic Acid Extraction Kit and the PrepSEQ Rapid Spin Sample Preparation Kit, were validated), the Applied Biosystems 7500 Fast Real-Time PCR instrument, and RapidFinder™ Express software. The test method was compared to the U.S. Department of Agriculture Microbiology Laboratory Guidebook 5.04 reference method for detecting E. coli O157:H7 in 25 g and 375 g ground beef and beef trim, and to the ISO 16654 reference method for detecting E. coli O157:H7 in 25 g spinach, orange juice, and apple juice. The MicroSEQ E. coli O157:H7 Detection Kit showed equivalent detection compared to the corresponding reference method based on Mantel-Haenszel Chi-square statistics for all matrixes tested. An independent validation confirmed these findings on ground beef. The MicroSEQ kit detected all 51 E. coli O157:H7 strains tested and showed good discrimination against an exclusivity panel of 30 strains.

Evaluation of VIDAS®Salmonella (SLM) Easy Salmonella Method for the Detection of Salmonella in a Variety of Foods: Collaborative Study

2011 ◽  
Vol 94 (6) ◽  
pp. 1821-1834 ◽  
Author(s):  
Erin Crowley ◽  
Patrick Bird ◽  
Kiel Fisher ◽  
Katherine Goetz ◽  
M Joseph Benzinger ◽  
...  
Keyword(s):  
Peanut Butter ◽  
Collaborative Study ◽  
Reference Method ◽  
The United States ◽  
Food Type ◽  
Chi Square ◽  
Selective Enrichment ◽  
Reference Methods ◽  
Chi Square Analysis ◽  
The U.S

Abstract The VIDAS®Salmonella (SLM) Easy Salmonella method is a specific enzyme-linked fluorescent immunoassay performed in the automated VIDAS instrument. The VIDAS Easy Salmonella method is a simple 2-step enrichment procedure, using pre-enrichment followed by selective enrichment in a newly formulated broth, SX2 broth. This new method was compared in a multilaboratory collaborative study to the U.S. Food and Drug Administration's Bacteriological Analytical Manual, Chapter 5 method for five food matrixes (liquid egg, vanilla ice cream, spinach, raw shrimp, and peanut butter) and the U.S. Department of Agriculture's Microbiology Laboratory Guidebook 4.04 method for deli turkey. Each food type was artificially contaminated with Salmonella at three inoculation levels. A total of 15 laboratories representing government, academia, and industry, throughout the United States, participated. In this study, 1583 samples were analyzed, of which 792 were paired replicates and 791 were unpaired replicates. Of the 792 paired replicates, 285 were positive by both the VIDAS and reference methods. Of the 791 unpaired replicates, 341 were positive by the VIDAS method and 325 were positive by the cultural reference method. A Chi-square analysis of each of the six food types was performed at the three inoculation levels tested. For all foods evaluated, the VIDAS Easy SLM method demonstrated results comparable to those of the reference methods for the detection of Salmonella.

scholarly journals Evaluation of the BAX® System for Detection of Salmonella in Selected Foods: Collaborative Study

2003 ◽  
Vol 86 (6) ◽  
pp. 1149-1159 ◽  
Author(s):  
Karen Silbernagel ◽  
Robert Jechorek ◽  
Charles Carver ◽  
W Mark Barbour ◽  
Peter Mrozinski ◽  
...  
Keyword(s):  
Orange Juice ◽  
Collaborative Study ◽  
Reference Method ◽  
Food Type ◽  
Mozzarella Cheese ◽  
Chi Square ◽  
Cultural Methods ◽  
Paired Samples ◽  
Cultural Method ◽  
Chi Square Analysis

Abstract A multilaboratory study was conducted to compare the automated BAX® System to the standard cultural methods for detection of Salmonella in selected foods. Five food types—frankfurters, raw ground beef, mozzarella cheese, raw frozen tilapia fish, and orange juice—at 3 inoculation levels, were analyzed by each method. A sixth food type, raw ground chicken, was tested using 3 naturally contaminated lots. A total of 16 laboratories representing government and industry participated. In this study, 1386 samples were analyzed, of which 1188 were paired samples and 198 were unpaired samples. Of the 1188 paired samples, 461 were positive by both methods and 404 were negative by both methods. Thirty-seven samples were positive by the BAX System but negative by the standard reference method, and 11 samples were positive by standard cultural method and negative by the BAX System. Of the 198 unpaired samples, 106 were positive by the BAX System and 60 were positive by the standard cultural method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, the BAX System demonstrated results comparable to those of the standard reference methods based on the Chi square results.

Substrate Supporting Disc Method for Confirmed Detection of Total Coliforms and E. coli in all Foods: Collaborative Study

1993 ◽  
Vol 76 (5) ◽  
pp. 988-1005 ◽  
Author(s):  
Philip T Feldsine ◽  
Maria T Falbo-Nelson ◽  
David L Hustead ◽  
◽  
J Aaronson ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Total Coliform ◽  
Food Type ◽  
Coliform Bacteria ◽  
Pork Sausage ◽  
E Coli ◽  
Fresh Frozen ◽  
Uninoculated Control ◽  
Liquid Milk ◽  
Control Samples

Abstract The Coli Complete® substrate supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with AOAC most probable number (MPN) methods, 966.23 and 966.24. Twenty-nine laboratories participated in this collaborative study in which 6 food types were analyzed. Four food types, raw ground beef, pork sausage, raw liquid milk, and nut meats, were naturally contaminated with coliform bacteria. Two foods, dry egg and fresh frozen vegetables, were seeded with coliforms. Three food types, ground beef, raw liquid milk, and pork sausage, were naturally contaminated with E. coli. Although pork sausage was naturally contaminated, the level was very low (<10/50 g); therefore, additional E. coli were inoculated into 1 lot of this food type. Three food types, nut meats, dry egg, and fresh frozen vegetables, were inoculated with E. coli. For naturally contaminated samples, duplicate determinations were made on 3 separate lots for each food type. For inoculated samples, low, medium, and high contamination levels plus uninoculated control samples were examined in duplicate. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN method. Results were then analyzed for repeatability, reproducibility, and mean log MPN statistical equivalence. Results were statistically equivalent for all total coliform levels in all food types except frozen vegetable and raw nut meat uninoculated control samples and 1 lot of pork sausage where the SSD method produced statistically significant greater numbers. For the E. coli determinations, results were statistically equivalent across all samples and all levels for each food type. The SSD method has been adopted first action by AOAC International for confirmed detection of total coliforms and E. coli in all foods.

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