Evaluation of the MC-Media PadTM Yeast and Mold Device for the Enumeration of Yeast and Mold: Collaborative Study, First Action 2018.02

2019 ◽  
Vol 102 (4) ◽  
pp. 1138-1144
Author(s):  
Patrick Bird ◽  
Benjamin Bastin ◽  
Dane Brooks ◽  
Erin Crowley ◽  
James Agin ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Control Level ◽  
Reference Method ◽  
Food Products ◽  
Plate Count ◽  
Contamination Level ◽  
Juice Concentrate ◽  
Uninoculated Control ◽  
The Difference ◽  
Contamination Levels

Abstract Background: The MC-Media Pad™ Yeast and Mold (YM) is a ready-to use culture device that combines a test pad coated with medium and water-absorption polymers that is designed for the rapid quantification of yeast and mold in food products. Objective: The MC-Media Pad YM was compared with the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) for the enumeration of yeast and mold in frozen orange juice concentrate. Methods: The candidate method was evaluated using a paired study design in a multilaboratory collaborative study following the current AOAC Validation Guidelines. Three target contamination levels (low, 10–100 CFU/g; medium, 100–1000 CFU/g; and high 1000–10 000 CFU/g) and an uninoculated control level (0 CFU/g) were evaluated. MC-Media Pad YM devices were enumerated after 48 and 72 h of incubation. Results: Plate count obtained by both methods were log-transformed and the difference of means (including 95% confidence intervals), repeatability SD, and SD were determined for each contamination level. Conclusions: No statistical difference was observed between the MC-Media Pad YM (for both 48 and 72 h) and the FDA BAM for each contamination level. Highlights: The new method offers a convenient alternative to the reference method (FDA BAM) for detection of yeast and mold contamination in food products, yielding reliable and comparable results in 48 h compared to 5 days for the reference method.

Evaluation of the MC-Media Pad® Rapid Aerobic Count Device for the Enumeration of Total Aerobic Counts in a Variety of Foods: Collaborative Study, First Action Official MethodSM 2019.02

2020 ◽  
Vol 103 (5) ◽  
pp. 1318-1325
Author(s):  
Benjamin Bastin ◽  
Nicole Klass ◽  
Erin Crowley ◽  
James Agin ◽  
Charlotte Lindhardt ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Collaborative Study ◽  
Food Products ◽  
Plate Count ◽  
Contamination Level ◽  
Microbial Count ◽  
Reference Methods ◽  
The Difference ◽  
Aerobic Plate Count ◽  
Inspection Service

Abstract Background The MC-Media Pad® Rapid Aerobic Count (RAC) is a ready-to-use culture device combining a test pad coated with medium and water absorption polymers that are designed for the rapid quantification of total aerobic bacteria in food products. Objective The MC-Media Pad RAC was compared to the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook, Chapter 3.02: Quantitative Analysis of Bacteria in Foods as Sanitary Indicators for raw ground pork and the Standard Methods for the Examination of Dairy Products, Chapter 6: Microbial Count Methods for yogurt drink. Method The candidate method was evaluated against the reference methods using a paired study design in a multi-collaborator study, following the current AOAC INTERNATIONAL Official Methods of AnalysisSM Appendix J guidelines. Three target contamination levels (low, medium, and high) were evaluated. MC-Media Pad RAC devices were enumerated after 24 and 48 h of incubation. Results Plate counts obtained by both methods were log10-transformed and the difference of means (including 95% confidence intervals), repeatability SD, and reproducibility SD were determined for each contamination level. All 95% confidence intervals for mean difference fell easily within ±0.10, the performance requirement being ±0.5. Conclusion The MC-Media Pad RAC (for both 24 and 48 h) and both reference methods for each contamination level were therefore shown to be equivalent, with 97.5% confidence. Highlights The new method offers a convenient alternative to the reference methods for detection of aerobic plate count in food products, yielding reliable and comparable results in 24 or 48 h compared to 48 h for the reference methods.

scholarly journals Evaluation of the GENE-UP ®E. coli O157:H7 Method for the Detection of E. coli O157:H7 in Select Foods: Collaborative Study, 2019.03

2020 ◽  
Vol 103 (5) ◽  
pp. 1338-1347
Author(s):  
Ronald Johnson ◽  
John Mills ◽  
Jean-Louis Pittet ◽  
Maryse Rannou ◽  
Patrick Bird ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Collaborative Study ◽  
Control Level ◽  
Reference Method ◽  
Probability Of Detection ◽  
Contamination Level ◽  
Test Portion ◽  
E Coli ◽  
Significant Difference ◽  
Contamination Levels

Abstract Background The GENE-UP®E. coli O157:H7 2 (ECO 2) assay (Performance Tested MethodSM 121805) incorporates Fluorescence Resonance Energy Transfer hybridization probes into its proprietary PCR technology for the rapid detection of E. coli O157:H7 in select foods. Objective The purpose of this validation was to evaluate the method’s interlaboratory performance and submit the result to AOAC INTERNATIONAL for adoption as First Action Official MethodSM for the detection of E. coli O157:H7 in select foods. Method The GENE-UP® method was evaluated in a multi-laboratory study as part of the MicroVal validation process using unpaired test portions for one food matrix, raw milk cheese (Comté, 34% fat, 0.8% salt). The candidate method was compared to the ISO 16654:2001 reference method. Fourteen participants from 13 laboratories throughout the European Union participated. Three levels of contamination were evaluated: a non-inoculated control level (0 colony-forming units (CFU)/test portion), a low contamination level (∼5 CFU/test portion), and a high contamination level (∼10 CFU/test portion). Data from that study were analyzed according to the Probability of Detection (POD) statistical model as presented in the AOAC validation guidelines. The difference in laboratory POD (dLPODC) values with 95% confidence interval across collaborators was calculated for each level between the candidate and reference method results, and between the candidate presumptive and confirmed results. Results The dLPODC values with 95% confidence interval were; 0.00 (–0.04, 0.04), 0.27 (0.04, 0.49), and 0.17 (0.01, 0.33) for the non-inoculated, low and high contamination levels respectively. Conclusions The dLPODC results indicate a significant difference between the candidate method and the reference method for both the low and high contamination levels, with the candidate method producing higher recovery of the target organism at both levels. Highlights The GENE-UP E. coli O157:H7 assay provides industry with a rapid, accurate detection method for E. coli O157:H7 in a broad range of foods.

Evaluation of the GENE-UP ® Listeria spp. Method for the Detection of Listeria Species in a Variety of Foods and Select Environmental Surfaces: Collaborative Study, First Action 2019.10

2020 ◽  
Author(s):  
Ronald Johnson ◽  
John Mills ◽  
Jean-Louis Pittet ◽  
Olivier Mathia ◽  
Patrick Bird ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Control Level ◽  
Reference Method ◽  
Probability Of Detection ◽  
Cottage Cheese ◽  
Contamination Level ◽  
Official Method ◽  
Test Portion ◽  
Listeria Species ◽  
Environmental Surfaces

Abstract Background The GENE-UP®Listeria spp. 2 (LIS 2) assay (Performance Tested MethodSM 121803) is a real-time PCR molecular detection method for the rapid detection of Listeria species (Listeria monocytogenes, L. innocua, L. ivanovii, L. seeligeri and L. welshimeri) in a variety of foods and environmental surfaces. Objective The purpose of this validation was to evaluate the method’s interlaboratory performance and submit the results to AOAC INTERNATIONAL for adoption as First Action Official MethodSM for the detection of Listeria species in a variety of foods and select environmental surfaces. Method The GENE-UP® method was evaluated in a multi-laboratory study as part of the AFNOR NF VALIDATION certification process using unpaired test portions for one food matrix, full-cream goat milk cottage cheese (8.4% fat). The candidate method was compared to the ISO 11290-1/Amd.1 reference method. Sixteen participants from 15 laboratories throughout the European Union participated. Three levels of contamination were evaluated: a non-inoculated control level (0 CFU/test portion), a low contamination level (∼2 CFU/test portion) and a high contamination level (∼10 CFU/test portion). Data from that study were analyzed according to the Probability of Detection (POD) statistical model. Results The dLPODC values with 95% confidence interval between the candidate and reference method results were; -0.02 (-0.07, 0.03), -0.08 (-0.31, 0.16) and 0.00 (-0.03, 0.03) for the non-inoculated, low and high contamination levels respectively. Conclusion The dLPODC results demonstrate no difference in performance between the candidate method and reference method for the matrix evaluated. Highlights Data from a singular collaborative study was used to achieve adoption as AOAC First Action Official Method for the detection of Listeria species in a variety of foods and select environmental surfaces.

Evaluation of the 3M™ Petrifilm™ Rapid Aerobic Count Plate for the Enumeration of Aerobic Bacteria: Collaborative Study, First Action 2015.13

2016 ◽  
Vol 99 (3) ◽  
pp. 664-675
Author(s):  
Patrick Bird ◽  
Jonathan Flannery ◽  
Erin Crowley ◽  
James Agin ◽  
David Goins ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Skim Milk ◽  
Plate Count ◽  
Aerobic Bacteria ◽  
Contamination Level ◽  
Standard Plate Count ◽  
Dual Sensor ◽  
Standard Plate ◽  
Aerobic Plate Count ◽  
Contamination Levels

Abstract The 3M™ Petrifilm™ Rapid Aerobic Count (RAC) Plate is a sample-ready culture medium system containing dual-sensor indicator technology for the rapid quantification of aerobic bacteria in food products. The 3M Petrifilm RAC Plate was compared to the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA BAM) Chapter 3 (Aerobic Plate Count) for the enumeration of aerobic bacteria in raw easy-peel shrimp and the Standard Methods for the Examination of Dairy Products (SMEDP) Chapter 6 (Standard Plate Count Method) for the enumeration of aerobic bacteria in pasteurized skim milk and instant nonfat dry milk (instant NFDM). The 3M Petrifilm RAC Plate was evaluated using a paired study design in a multilaboratory collaborative study following current AOAC validation guidelines. Three target contamination levels (low, 10–100 CFU/g; medium, 100–1000 CFU/g; and high 1000–10 000 CFU/g) were evaluated for naturally occurring aerobic microflora for each matrix. For raw easy-peel shrimp, duplicate 3M Petrifilm RAC Plates were enumerated after 24 ± 2 h incubation at both 32 and 35°C. Pasteurized skim milk 3M Petrifilm RAC Plates were enumerated after 24 ± 2 h incubation at 32°C, and instant NFDM 3M Petrifilm RAC Plates were enumerated after 48 ± 3 h incubation at 32°C. No statistical difference was observed between 3M Petrifilm RAC Plate and FDA BAM or SMEDP reference methods for each contamination level.

Evaluation of the GENE-UP® EHEC Detection Method for the Detection of Enterohemorrhagic E. coli in Select Foods: Collaborative Study: First Action Method 2020.06

2021 ◽  
Author(s):  
Ronald Johnson ◽  
John Mills ◽  
Jean-Louis Pittet ◽  
Maryse Rannou ◽  
Patrick Bird
Keyword(s):  
Detection Method ◽  
Collaborative Study ◽  
False Negative ◽  
Control Level ◽  
Reference Method ◽  
Probability Of Detection ◽  
Contamination Level ◽  
Official Method ◽  
Test Portion ◽  
E Coli

Abstract Background The GENE-UP® EHEC assay (Performance Tested MethodSM 121806) is a real-time PCR molecular detection method that utilizes Fluorescence Resonance Energy Transfer proprietary hybridization probes for the rapid detection of Enterohemorrhagic E. coli (EHEC) in select foods. Objective The purpose of this validation was to evaluate the method’s interlaboratory performance and submit the results to AOAC INTERNATIONAL for adoption as First Action Official Method of AnalysisSM for the detection of EHEC in select foods. Method The GENE-UP® method was evaluated in a multi-laboratory study as part of the MicroVal VALIDATION certification process using unpaired test portions for one food matrix, raw ground beef (85% lean). Collaborators evaluated the candidate method using either an automated or manual lysis procedure. The candidate method was compared to the ISO/TS 13136:2012 method. Data from 17 participants from 15 laboratories throughout the European Union was evaluated. Three levels of contamination were evaluated: a non-inoculated control level (0 CFU/test portion), a low contamination level (∼1 CFU/test portion) and a high contamination level (∼10 CFU/test portion). Data from the study were analyzed according to the probability of detection (POD) statistical model. Results The dLPODC values with 95% confidence interval between the candidate and reference method results were; –0.01 (–0.04, 0.02), 0.23 (0.07, 0.39) and 0.06 (0.01, 0.12) for the non-inoculated, low and high contamination levels, respectively. Conclusion For the candidate method, values obtained for repeatability and reproducibility were similar to the reference method and indicated minimal variation between samples or between laboratories. No discrepant results (false positive or false negative) were observed for each contamination. A statistical difference was calculated between the candidate and reference method at the low and high inoculation levels, with the candidate method detecting a higher number of positive samples indicating a higher sensitivity than the reference method. No differences in the recovery of the target analyte were observed between the manual and automated lysis procedures. Highlights The GENE-UP EHEC Detection Method provides end users a rapid, easy-to-use workflow for the detection of EHEC in food matrices.

Collaborative Study of the Impedance Method for Examining Raw Milk Samples

1984 ◽  
Vol 47 (9) ◽  
pp. 707-712 ◽  
Author(s):  
R. FIRSTENBERG-EDEN
Keyword(s):  
Collaborative Study ◽  
Raw Milk ◽  
Plate Count ◽  
Impedance Method ◽  
Standard Plate Count ◽  
Milk Samples ◽  
Automated Method ◽  
Significant Difference ◽  
Standard Plate ◽  
Contamination Levels

The impedance method is a rapid automated method for determining bacteriological contamination levels. A collaborative study was done to establish the reproducibility of the impedance method in predicting counts of raw milk. Frozen and unfrozen raw milk samples, with counts in the range of 9 × 104 to 4 × 107 CFU/ml, were sent to six laboratories to be examined by the standard plate count method (SPC) and by the impedance method which produced Bactometer-predicted counts (BPC). The impedance results showed less variability than SPC among laboratories in all three trials. The variance between split samples was also smaller for the impedance method than for SPC. However, the variance between duplicate plates of the same sample was significantly smaller for SPC than for BPC. In one trial, the means of BPC and SPC were not significantly different, whereas in another trial there was a significant difference of ca. log10 0.27 between the means of the two methods. However, in this trial the extreme differences between laboratories counting the same sample were log10 0.42.

scholarly journals Evaluation of the Solus One Salmonella Assay in Select Foods: Collaborative Study: First Action 2020.03

2020 ◽  
Vol 103 (6) ◽  
pp. 1568-1581
Author(s):  
Benjamin Bastin ◽  
M Joseph Benzinger ◽  
Erin S Crowley ◽  
James Agin ◽  
Raymond Wakefield
Keyword(s):  
United States ◽  
Statistical Analysis ◽  
Collaborative Study ◽  
Control Level ◽  
Reference Method ◽  
The United States ◽  
Probability Of Detection ◽  
Inoculum Level ◽  
Test Portion ◽  
The Matrix

Abstract Background The Solus One Salmonella immunoassay utilizes Salmonella specific selective media and automated liquid handling, for the rapid and specific detection of Salmonella species in select food types. Objective The candidate method was evaluated using 375 g test portions in an unpaired study design for a single matrix, instant non-fat dry milk (NFDM) powder. Method The matrix was compared to the United States Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference method. Eleven participants from 10 laboratories within academia and industry, located within the United States, Mexico, South Africa, Germany, and the United Kingdom, contributed data for the collaborative study. Three levels of contamination were evaluated for each matrix: an uninoculated control level [0 colony forming units (CFU)/test portion], a low inoculum level (0.2–2 CFU/test portion) and a high inoculum level (2–5 CFU/test portion). Statistical analysis was conducted according to the Probability of Detection (POD) statistical model. Results Results obtained for the low inoculum level test portions produced a dLPOD value with a 95% confidence interval between the candidate method confirmed (both alternative and conventional confirmation procedures) and the reference method of 0.07 (−0.02, 0.15). Conclusions The dLPOD results indicate equivalence between the candidate method and the reference method for the matrix evaluated and the method demonstrated acceptable inter-laboratory reproducibility as determined in the collaborative evaluation. False positive and false negative rates were determined for the matrix and produce values of <2%. Highlights Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis.

Evaluation of the GENE-UP ® Listeria monocytogenes Method for the Detection of Listeria monocytogenes in a Variety of Foods and Select Environmental Surfaces: Collaborative Study, First Action 2019.11

2020 ◽  
Author(s):  
Ronald Johnson ◽  
John Mills ◽  
Jean-Louis Pittet ◽  
Olivier Mathia ◽  
Patrick Bird ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Collaborative Study ◽  
Control Level ◽  
Reference Method ◽  
Probability Of Detection ◽  
Cottage Cheese ◽  
The European Union ◽  
Inoculum Level ◽  
Test Portion ◽  
Environmental Surfaces

Abstract Background The GENE-UP®Listeria monocytogenes 2 (LMO 2) assay (Performance Tested MethodSM 121804) uses real-time PCR technology and a proprietary detection platform, the GENE-UP® Thermocycler, to detect Listeria monocytogenes in a variety of foods and environmental surfaces. Objective The purpose of this validation was to evaluate the method’s interlaboratory performance and submit the result to AOAC INTERNATIONAL for adoption as First Action Official MethodSM for the detection of Listeria monocytogenes in a variety of foods and select environmental surfaces. Method The GENE-UP® method was evaluated in a multi-laboratory study as part of the AFNOR NF VALIDATION certification process using unpaired test portions for one food matrix, full-cream goat milk cottage cheese (8.4% fat). The candidate method was compared to the ISO 11290-1/Amd.1:2004 reference method. Sixteen participants from 15 laboratories throughout the European Union participated. Three levels of contamination were evaluated: a non-inoculated control level (0 CFU/test portion), a low inoculum level (∼2 CFU/test portion) and a high inoculum level (∼10 CFU/test portion). Data from the study were analyzed according to the Probability of Detection (POD) statistical model as presented in the AOAC validation guidelines. Results The dLPODC values with 95% confidence interval for each comparison were; -0.02 (-0.07, 0.03), -0.08 (-0.31, 0.16) and 0.00 (-0.03, 0.03) for the non-inoculated, low and high contamination levels respectively. Conclusion The dLPODC results demonstrate no difference in performance between the candidate method and reference method for the matrix evaluated. Highlights The GENE-UP LMO method demonstrated accuracy and precision in detecting and discerning L. monocytogenes from other Listeria species.

Rapid detection of microbial contamination in grape juice by flow cytometry

OENO One ◽  
1999 ◽  
Vol 33 (1) ◽  
pp. 31 ◽  
Author(s):  
Marielle Bouix ◽  
Agnès Grabowski ◽  
Monique Charpentier ◽  
Jean-Yves Leveau ◽  
Bruno Duteurtre
Keyword(s):  
Flow Cytometry ◽  
Reference Method ◽  
Grape Juice ◽  
Plate Count ◽  
Contamination Level ◽  
Cell Counts ◽  
Direct Cell ◽  
Micro Organisms ◽  
High Degree

<p style="text-align: justify;">This study presents an application of flow cytometry to evaluate rapidly the viable micro-organisms in grape juice. In this method, viable cells are firstly specitically labelled with a fluorescent reagent. The sample is then injected into the flow cytometer where the labelled micro-organisms are individually illuminated by a laser beam. The emission of fluorescence is measured. The system counts the number of fluorescent events and prints out a histogram of the fluorescence intensity which is characteristic of the micro-organism being analysed. In laboratory conditions, preliminary trials have been undertaken with an artificially inoculated grape juice with pure yeast and bacteria cultures. This method succeeded in counting simultaneously yeasts and bacteria within 15 minutes, with a high degree of sensitivity, 5.10<sup>3</sup> yeasts perml and 5.10<sup>4</sup> bacteria per ml. This technique can also be applied to the detection of mould contamination and the test has been done with <em>Botrytis</em> spores. The method makes direct cell counts possible and is capable of analysing 30 samples per hour. It can be automatised and easily used in industrial laboratory. During the last harvest, more than a thousand of must samples were controled using this technique. The results let to determine the yeast contamination level of a grape juice tank even before unloading. The results obtained by flow cytometry were compared to the plate count reference method. The correlation between cytometry and count by plate culture was 99 p. cent for the threshold of 5.1 0<sup>4</sup> yeasts/ml which seemed to point out a high contamination. By using this flow cytometry method during the harvest period, the results were supplied in real time. This allowed a rapid selection of the musts, depending upon the scale of their contamination and improved the quality of the wine by corrective actions.</p>

scholarly journals Singlepath Salmonella

2009 ◽  
Vol 92 (6) ◽  
pp. 1885-1889 ◽  
Author(s):  
Charlotte Lindhardt ◽  
Holger Schönenbrücher ◽  
Jörg Slaghuis ◽  
Andreas Bubert ◽  
Rolf Ossmer ◽  
...  
Keyword(s):  
Peanut Butter ◽  
Reference Method ◽  
Black Pepper ◽  
Contamination Level ◽  
Salmonella Spp ◽  
Chi Square ◽  
Qualitative Detection ◽  
Significant Difference ◽  
Uninoculated Control ◽  
High Level

Abstract Singlepath Salmonella is an immunochromatographic (lateral flow) assay for the presumptive qualitative detection of Salmonella spp. in food. A previous AOAC Performance Tested MethodSM study evaluated Singlepath Salmonella as an effective method for the detection of Salmonella spp. in the following selected foods: dried skimmed milk, black pepper, dried pet food, desiccated coconut, cooked peeled frozen prawns, raw ground beef, and raw ground turkey. In this Emergency Response Validation extension, creamy peanut butter was inoculated with S. enterica. ser. Typhimurium. For low contamination level (1.08 CFU/25 g), a Chi-square value of 0.5 indicated that there was no significant difference between Singlepath Salmonella and the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) reference method. For high-level and uninoculated control there was 100 agreement between the methods.

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