Method Modification of the Legipid®Legionella Fast Detection Test Kit

2014 ◽  
Vol 97 (5) ◽  
pp. 1403-1409 ◽  
Author(s):  
Guillermo Rodríguez Albalat ◽  
Begoña Bedrina Broch ◽  
Marisa Jiménez Bono
Keyword(s):  
Legionella Pneumophila ◽  
Reference Method ◽  
Culture Method ◽  
Test Method ◽  
Magnetic Microspheres ◽  
Test Portion ◽  
Relative Level ◽  
Fast Detection ◽  
Test Kit ◽  
Optical Reader

Abstract Legipid®Legionella Fast Detection is a test based on combined magnetic immunocapture and enzyme-immunoassay (CEIA) for the detection of Legionella in water. The test is based on the use of anti-Legionella antibodies immobilized on magnetic microspheres. Target microorganism is preconcentrated by filtration. Immunomagnetic analysis is applied on these preconcentrated water samples in a final test portion of 9 mL. The test kit was certified by the AOAC Research Institute as Performance Tested MethodSM (PTM) No. 111101 in a PTM validation which certifies the performance claims of the test method in comparison to the ISO reference method 11731-1998 and the revision 11731-2004 “Water Quality: Detection and Enumeration of Legionella pneumophila” in potable water, industrial water, and waste water. The modification of this test kit has been approved. The modification includes increasing the target analyte from L. pneumophila to Legionella species and adding an optical reader to the test method. In this study, 71 strains of Legionella spp. other than L. pneumophila were tested to determine its reactivity with the kit based on CEIA. All the strains of Legionella spp. tested by the CEIA test were confirmed positive by reference standard method ISO 11731. This test (PTM 111101) has been modified to include a final optical reading. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Two water matrixes were analyzed. Results show no statistically detectable difference between the test method and the reference culture method for the enumeration of Legionella spp. The relative level of detection was 93 CFU/volume examined (LOD50). For optical reading, the LOD was 40 CFU/volume examined and the LOQ was 60 CFU/volume examined. Results showed that the test Legipid Legionella Fast Detection is equivalent to the reference culture method for the enumeration of Legionella spp.

Validation of the Legipid® Bioalarm Legionella Assay

2012 ◽  
Vol 95 (5) ◽  
pp. 1440-1451 ◽  
Author(s):  
Guillermo Rodríguez Albalat ◽  
Begoña Bedrina Broch ◽  
Marisa Jiménez Bono
Keyword(s):  
Legionella Pneumophila ◽  
Water Samples ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Reference Method ◽  
Culture Method ◽  
Magnetic Microspheres ◽  
Test Volume ◽  
Significant Difference

Abstract Legipid® Bioalarm Legionella is a test based on combined magnetic immunocapture and enzyme-immunoassay (CEIA) for the detection of Legionella pneumophila in water. Anti-L. pneumophila antibodies are immobilized on magnetic microspheres. Immunomagnetic analysis is applied to preconcentrated water samples in a final test volume of 9 mL. The method was compared with the standard culture method on both spiked and naturally contaminated water samples. The test was evaluated in potable, industrial, and natural water matrixes, according to the scope of the ISO 11731 reference method. These waters were tested with the target at levels ranging from low (10–99 CFU/mL) to high (100–999 CFU/mL); a Chi-square value of 1.8 indicated that there was no significant difference between the test and the reference method. The false-positive rate was 7%, and the false-negative rate 2%. For the inclusivity study, all 17 strains of L. pneumophila of different serogroups reacted with the test. For the exclusivity study, 17 strains of other Legionella species and 16 non-Legionella strains were tested. There were no cross-reactions with non-Legionella strains. L. beliardensis, L. adelaidensis, and one environmentally isolated Legionella sp. produced a positive result at high concentrations of 1800, 230, and 3900 CFU/mL, respectively. Agreement between the two methods was 95.9%.

scholarly journals The Validation of the Sample6 DETECTTM HT/L for AOAC Research Institute

2018 ◽  
Vol 101 (5) ◽  
pp. 1584-1592
Author(s):  
Kakolie Banerjee ◽  
Brittney Pierson ◽  
Chuxuan Hu ◽  
Elijah Carrier ◽  
Lauren Malsick ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Incubation Temperature ◽  
Detection System ◽  
Reference Method ◽  
Culture Method ◽  
The Elderly ◽  
Sample Volume ◽  
Test Portion ◽  
Environmental Surfaces ◽  
The Matrix

Abstract Background: Listeria spp. are an important foodborne human pathogen because of their ability to cause disease and high mortality in individuals, particularly pregnant women, neonates, the elderly, immunocompromised individuals, and children. The Sample6 DETECTTM HT/L Kit is a semi-automated qualitative pathogen detection system designed to detect Listeria spp. (L. monocytogenes, L. innocua, L. ivanovii, L. seeligeri, L. welshimeri, and L. marthii) in environmental samples using the Sample6 BioIlluminationTM technology. Objective: The study was done to evaluate the Sample6 DETECT HT/L Kit. The assay was evaluated for inclusivity, exclusivity, robustness, product consistency, and stability, and a matrix study of one environmental surface. Methods: The performance of the Sample6 DETECT HT/L was compared with U.S. Food and Drug Administration reference culture method for Listeria using an unpaired study design. Results: The Sample6 DETECT HT/L assay correctly identified all 50 inclusivity isolates and correctly excluded all 30 nontarget strains evaluated. The assay was not affected by minor variations in incubation temperature and time, or sample volume. Results across three production lots spanning the shelf life of the assay were consistent. In the matrix study, the Sample6 DETECT HT/L for Listeria correctly identified each test portion for the presence or absence of Listeria, and there were no statistically significant differences between candidate and reference method results. Conclusions: The data collected in this study demonstrate that the Sample6 DETECT HT/L assay is a reliable method for the detection of Listeria spp. on stainless-steel environmental surfaces after 22 h of enrichment.

InstantLabs®Salmonella Species Detection Method: Matrix Extension

2014 ◽  
Vol 97 (6) ◽  
pp. 1585-1591
Author(s):  
Neil Sharma ◽  
Lauren Bambusch ◽  
Thu Le ◽  
Amit Morey ◽  
Melinda Hayman ◽  
...  
Keyword(s):  
Ground Beef ◽  
Reference Method ◽  
Test Method ◽  
Chicken Breast ◽  
Escherichia Coli O157 ◽  
Test Portion ◽  
Screen Result ◽  
Low Levels ◽  
Matrix Extension ◽  
Better Than

Abstract The performance of InstantLabs®Salmonella Species Food Safety Kit to detect Salmonella in four food matrixes was validated against the International Organization for Standardization (ISO) reference method 6579:2002. The matrixes (raw ground beef, raw chicken breast, raw ground chicken, and lettuce) were inoculated with low levels of Salmonella (<1 CFU/test portion) to generate fractional positives (5–15) in 20 inoculated samples. These matrixes were co-inoculated with Escherichia coli O157:H7 at two to five times the level of Salmonella. Samples were validated using 375 g (meat) or 25 g (lettuce and poultry) test portions enriched in FASTGRO™ SE at 42 ± 1°C for 12 h and 10 h, respectively. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method was shown to perform as well as or better than the reference method for the detection of Salmonella species in ground beef, chicken breast, ground chicken, and lettuce. Inclusivity and exclusivity testing revealed no false negatives among the 100 Salmonella serovars and no false positives among the 30 non-Salmonella species examined, respectively.

InstantLabs®Salmonella Species Food Safety Kit

2014 ◽  
Vol 97 (6) ◽  
pp. 1576-1584
Author(s):  
Neil Sharma ◽  
Lauren Bambusch ◽  
Thu Le ◽  
Melinda Hayman ◽  
Sergio J Montez
Keyword(s):  
Food Safety ◽  
Wheat Flour ◽  
Enrichment Culture ◽  
Hold Time ◽  
Reference Method ◽  
Test Method ◽  
Test Portion ◽  
Screen Result ◽  
Oat Flour ◽  
Better Than

Abstract The InstantLabs®Salmonella Species Food Safety Kit was validated against the International Organization for Standardization (ISO) reference method 6579:2002 for the detection of Salmonella species. The matrixes (unprocessed rolled oats, wheat flour, and oat flour) were inoculated with 1 CFU/test portion of Salmonella to generate fractional positives (5–15) in 20 inoculated samples. The matrixes were co-inoculated with Escherichia coli O157:H7 at 2–5 times the level of Salmonella to demonstrate the potential for using the same enrichment culture in the future to detect of multiple organisms. Samples were validated using 750 g test portion enriched in FASTGRO SE at 42 ± 1°C for 16–20 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of Salmonella species in unprocessed rolled oats, wheat flour, and oat flour. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non-Salmonella species examined. Finally, the method was shown to be robust when variations to enrichment time, DNA extract hold time, and DNA volume were varied (data not shown).

Vivione Bioscience RAPID-B®E. coli O157 Test Kit and non-O157 STEC Test Kit Evaluation

2015 ◽  
Vol 98 (2) ◽  
pp. 371-378 ◽  
Author(s):  
Melinda Miller ◽  
Shawn Ramsaroop ◽  
Chris Lopez ◽  
Bharath Brahmanda
Keyword(s):  
High Performance ◽  
Diagnostic System ◽  
Brain Heart Infusion ◽  
Reference Method ◽  
Test Methods ◽  
Cell Surface Antigens ◽  
Test Portion ◽  
E Coli ◽  
Test Kit ◽  
B Test

Abstract RAPID-B® is a high performance, integrated microbiology/infectious disease diagnostic system. The system uses hardware and software that are specifically designed for optimal detection using custom, immuno-based reagents designed to react to cell surface antigens of the target bacteria. The Vivione Bioscience RAPID-B Escherichia coli O157 and non-O157 Shiga toxin-producing E. coli (STEC) kits were validated alongside the U.S. Department of Agriculture, Food Safety and Inspection Service (FSIS), Microbiology Laboratory Guidebook (MLG) 5.07 (for E. coli O157) and FSIS MLG 5B.04 (fornon-O157 STEC) reference methods for the detection of E. coli O157 and STEC. The matrixes, ground beef and beef trim, were inoculated with appropriate CFU/test portion of E. coli O157 and STEC so as to generate fractional positives results, 5 to 15 positives out of 20 inoculated samples. Samples were enriched in prewarmed Brain Heart Infusion broth at 42 ± 1°C for 6.5–7.5 h or 8.5–9.5 h depending on thesample size. All samples were confirmed using the MLG reference method, regardless of initial screen result. The RAPID-B test methods were statistically equivalent to the reference method for the detection ofE. coli O157 and STEC in all testedsamples. Inclusivity and exclusivity testing of the RAPID-B methods showed 100% specificity for both kits. Finally, the RAPID-B test methods were shown to be robust when variations were applied to enrichment time, broth temperature, and vortexing time.

Detection of Salmonella species in a Variety of Foods by the DuPont™ BAX® System Real-Time PCR Assay for Salmonella: First Action 2013.02

2014 ◽  
Vol 97 (3) ◽  
pp. 868-875 ◽  
Author(s):  
F Morgan Wallace ◽  
Bridget Andaloro ◽  
Dawn Fallon ◽  
Nisha Corrigan ◽  
Stephen Varkey ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Orange Juice ◽  
Collaborative Study ◽  
Reference Method ◽  
Probability Of Detection ◽  
Test Method ◽  
Pcr Assay ◽  
Test Portion ◽  
Significant Difference

Abstract A multilaboratory study was conducted to evaluate the ability of the DuPont™ BAX® System Real-Time PCR Assay for Salmonella to detect the target species in a variety of foods and environmental surfaces. Internal validation studies were performed by DuPont Nutrition & Health on 24 different sample types to demonstrate the reliability of the test method among a wide variety of sample types. Two of these matrixes—pork and turkey frankfurters and pasteurized, not-from-concentrate orange juice without pulp—were each evaluated in 14 independent laboratories as part of the collaborative study to demonstrate repeatability and reproducibility of the internal laboratory results independent of the end user. Frankfurter samples were evaluated against the U. S. Department of Agriculture, Food Safety and Inspection Service reference method as a paired study, while orange juice samples were evaluated against the U. S. Food and Drug Administration reference method as an unpaired study, using a proprietary media for the test method. Samples tested in this study were artificially inoculated with a Salmonella strain at levels expected to produce low (0.2–2.0 CFU/test portion) or high (5 CFU/test portion) spike levels on the day of analysis. For each matrix, the collaborative study failed to show a statistically significant difference between the candidate method and the reference method using the probability of detection statistical model.

InstantLabs®E. coli O157 Food Safety Kit

2015 ◽  
Vol 98 (1) ◽  
pp. 71-81
Author(s):  
Neil Sharma ◽  
Lauren Bambusch ◽  
Apala Upadhyay ◽  
Thu Le ◽  
Chris Lopez ◽  
...  
Keyword(s):  
Food Safety ◽  
Enrichment Culture ◽  
Reference Method ◽  
Test Method ◽  
Romaine Lettuce ◽  
Test Portion ◽  
E Coli ◽  
Screen Result ◽  
Block Time ◽  
Better Than

Abstract The InstantLabs®E. coli O157 Food Safety Kit was validated against the International Organization for Standardizationreference method 16654 for the detection of Escherichia coli O157. The matrixes, raw ground beef, raw beef trim, Romaine lettuce, pasteurized apple juice, and raw ground chicken, were inoculated with appropriate CFU/test portion of E. coli O157 to generate fractional positives (5–15) in 20 inoculated samples. The matrixeswere co-inoculated with Salmonella at 2–5 times the level of E. coli O157 to demonstrate the potential for using the same enrichment culture for the detection of multiple organisms. Samples were enriched in prewarmed FASTGRO SE broth at 42 ± 1°C for 10–20 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of E. coli O157 in all tested samples. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 E. coli O157 serovars and 30 non-E. coli O157 species examined. Finally, the method was shown to be robust when variations were applied to enrichment time, volume for DNA extraction, and heat block time.

GlutenTox® Pro Test for the Detection of Gluten in Select Foods and Surfaces

2015 ◽  
Vol 98 (6) ◽  
pp. 1608-1627 ◽  
Author(s):  
Miguel A Síglez ◽  
Bárbara Nocea ◽  
María del Mar Pérez ◽  
Eva Mª García ◽  
Laura León ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Concentration Level ◽  
Reference Method ◽  
Rice Flour ◽  
Test Method ◽  
Laboratory Evaluation ◽  
Food Matrix ◽  
Detection Thresholds ◽  
Test Kit ◽  
Environmental Surface

Abstract The GlutenTox® Pro Test is an immunochromatographic test for the detection of gluten in foods and on surfaces with varying compositions and levels of processing, from raw foods/ingredients to final product testing. The Method Developer evaluation for the validation of the GlutenTox Pro Test Kit (Biomedal Diagnostics, Sevilla, Spain) for the detection of gluten in foods and on surfaces was conducted at Biomedal, S. L., Camas, Sevilla, Spain. The GlutenTox Pro test method was evaluated by testing the following: cross-reactivity, interference, specificity and sensitivity, robustness, stability, lot-to-lot variation, food matrix, and environmental surface. To evaluate the performance of the GlutenToxPro test for the detection of gluten, 10 matrixes were selected: rice flour, bread/biscuit, rolled oat, pâté, and yogurt (and a second bread matrix for incurred sampled testing) for the food matrix study and food-grade painted wood, plastic, rubber, sealed ceramic, and stainless steel for the environmental surface matrix study. For the food matrix study, 30 replicates were evaluated at six spiked levels of gluten (0, 3, 8, 15, 25, and 45 ppm) against four detection thresholds (5, 10, 20, and 40 ppm) for each food matrix. Additionally, 10 replicates were evaluated at a concentration of 10 000 ppm using all four detection thresholds only for rice flour matrix. Three replicates of each concentration level of gluten were analyzed using paired samples by the AOAC OMA 2012.01 reference method for each food matrix. For the environmental surface study, 30 replicates were evaluated at a low spike level of gluten (16 ng/16 cm2), five replicates at a high spike level of gluten (400 ng/16 cm2), and five replicates at an unspiked control level (0 ng/16 cm2) for each surface matrix. Upon completion of testing, the probability of detection values and confidence intervals were calculated and plotted versus the concentration level as determined by the reference method when applicable. An independent laboratory evaluation of the GlutenTox Pro Test Kit with rice flour and stainless steel environmental surface was conducted at Q Laboratories, Inc. (Cincinnati, OH). The GlutenTox Pro Test Kit demonstrated reliability as an effective rapid method for the detection of gluten in food matrixes (LOD 5 ppm gluten; threshold limits 5, 10, 20, and 40 ppm gluten) and on environmental surfaces (amount of detection 16 ng/16 cm2).

scholarly journals Determination of Fat in Raw and Processed Milks by the Gerber Method: Collaborative Study

2001 ◽  
Vol 84 (5) ◽  
pp. 1499-1508 ◽  
Author(s):  
Dick H Kleyn ◽  
Joanna M Lynch ◽  
David M Barbano ◽  
M Jeffrey Bloom ◽  
Martin W Mitchell ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Reference Method ◽  
Fat Content ◽  
Interlaboratory Study ◽  
Test Portion ◽  
Ether Extraction ◽  
Whole Milk ◽  
Relative Standard ◽  
Extraction Test ◽  
Fat Level

Abstract The Gerber method is used worldwide as a simple and rapid method for determining fat in raw and processed milks. However, the volume of the test portion used in the method has not been internationally agreed upon. A collaborative study was conducted to evaluate performance of the Gerber method using either a weighed test portion (11.13 g) or by a 10.77 mL test portion delivered by pipet. For each method, laboratories received 10 test samples: 5 raw and 5 pasteurized homogenized milks, 2 of which were blind duplicate pairs. Eleven and 10 laboratories participated in the evaluation of aliquot addition by weight and pipet, respectively. Mojonnier ether extraction (Method 989.05) was used as the reference method. Interlaboratory study statistics were similar between methods of test portion addition and between raw and processed materials; therefore, summary interlaboratory study statistics were pooled. The fat content of milk samples ranged from 0.96 to 5.48%. Absolute reproducibility and repeatability were not affected by fat level, and pooled statistical performance (invalid and outlier data removed) was (g fat/100 g milk) sr = 0.026, sR = 0.047, r = 0.074, and R = 0.132. Relative standard deviations increased with decreasing fat content, and were summarized by fat level: 1–2% fat milk, mean = 1.437, RSDr = 1.809%, RSDR = 3.271%; 2–6% fat milk, mean = 4.156, RSDr = 0.626%, RSDR = 1.131%. Compared with ether extraction, test results by the Gerber method were slightly lower (0.02% fat) using a weighed test portion and significantly lower (0.06% fat) using a 10.77 mL volume addition by pipet. A trend toward underestimating fat content at lower fat concentrations (1–2% fat) was observed with the weighed test portion but not when a pipet was used. The Associate Referee recommends that the Gerber method using a weighed test portion be adopted as First Action with applicability limited to whole milk.

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