scholarly journals CHROMagar Salmonella Detection Test Kit

2009 ◽  
Vol 92 (6) ◽  
pp. 1906-1909 ◽  
Author(s):  
Katana Webb ◽  
Vicki Ritter ◽  
Thomas Hammack
Keyword(s):  
Food Environment ◽  
Room Temperature ◽  
Peanut Butter ◽  
Reference Method ◽  
Testing Laboratory ◽  
Inoculum Level ◽  
Test Kit ◽  
Uninoculated Control ◽  
Positive Results ◽  
Method Agreement

Abstract BBL CHROMagar Salmonella was evaluated by an external food testing laboratory for the recovery of Salmonella in peanut butter using the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) procedure. The peanut butter was found to be negative for the presence of Salmonella and, therefore, was seeded with heat-stressed Salmonella at target concentrations of 0.2 and 2 CFU/25 g. The Salmonella-seeded samples remained at room temperature for 14 days before analysis to stabilize the Salmonella in the food environment. Twenty 25 g test portions from each seeded level and five 25 g samples of uninoculated control samples were processed using enrichment broths as outlined in the FDA-BAM procedure. BBL CHROMagar Salmonella-prepared plates were evaluated with the FDA reference method media (bismuth sulfite, xylose lysine desoxycholate, and Hektoen enteric agars). Fractionally positive results were obtained from the lower inoculum level of peanut butter samples. Five positive cultures were recovered from both the BBL CHROMagar Salmonella and reference methods. The two methods gave identical results for all cultures resulting in a method agreement of 100%. McNemar's 2 test, which assesses the evidence for difference in marginal proportions between two methods, could not be evaluated because it requires one or more discrepant cultures. However, because there were no discrepant cultures, the marginal proportions for the two methods were identical; therefore, there is no evidence of a difference between the methods. This study demonstrates that the results from BBL CHROMagar Salmonella are comparable to the three reference method media for the detection of Salmonella in peanut butter using the FDA-BAM procedures.

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.

scholarly journals iQ-Check Salmonella II: Real-Time Polymerase Chain Reaction Test Kit

2009 ◽  
Vol 92 (6) ◽  
pp. 1865-1870 ◽  
Author(s):  
Wendy F Lauer ◽  
Caroline D Sidi ◽  
Jean-Philippe Tourniaire ◽  
Thomas Hammack
Keyword(s):  
Real Time ◽  
Peanut Butter ◽  
Reference Method ◽  
Polymerase Chain Reaction Test ◽  
Target Sequence ◽  
Chi Square ◽  
Test Kit ◽  
Significant Difference ◽  
Chi Square Analysis ◽  
Chain Reaction Test

Abstract iQ-Check Salmonella II is a real-time PCR kit for detection of Salmonella in foods. Specific oligonucleotide probes are used to detect target DNA during the amplification, by hybridizing to the amplicons. These probes are linked to a fluorophore, which fluoresces only when hybridized to the target sequence. As part of an Emergency Response Validation due to a massive outbreak and subsequent recall, peanut butter was tested to compare the performance of iQ-Check Salmonella II to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) reference method for detection of Salmonella. A single enrichment in buffered peptone water was used for a reduced enrichment time of 21 1 h over the 48 h reference method. There was no significant difference in the performance of the iQ-Check kit when compared to the FDA-BAM method, as determined by Chi-square analysis. All samples identified as positive by iQ-Check were confirmed by reference method protocol.

scholarly journals DuPont Qualicon BAX System Polymerase Chain Reaction Assay

2009 ◽  
Vol 92 (6) ◽  
pp. 1902-1905 ◽  
Author(s):  
George Tice ◽  
Bridget Andaloro ◽  
Dawn Fallon ◽  
Erin Crowley ◽  
Amy C Remes ◽  
...  
Keyword(s):  
Room Temperature ◽  
Peanut Butter ◽  
Brain Heart Infusion ◽  
Detection Methods ◽  
Most Probable Number ◽  
Probable Number ◽  
System Method ◽  
Testing Site ◽  
Negative Controls ◽  
Positive Results

Abstract A recent outbreak of Salmonella in peanut butter has highlighted the need for validation of rapid detection methods. A multilaboratory study for detecting Salmonella in peanut butter was conducted as part of the AOAC Research Institute Emergency Response Validation program for methods that detect outbreak threats to food safety. Three sites tested spiked samples from the same master mix according to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) method and the BAX System method. Salmonella Typhimurium (ATCC 14028) was grown in brain heart infusion for 24 h at 37C, then diluted to appropriate levels for sample inoculation. Master samples of peanut butter were spiked at high and low target levels, mixed, and allowed to equilibrate at room temperature for 2 weeks. Spike levels were low [1.08 most probable number (MPN)/25 g]; high (11.5 MPN/25 g) and unspiked to serve as negative controls. Each master sample was divided into 25 g portions and coded to blind the samples. Twenty portions of each spiked master sample and five portions of the unspiked sample were tested at each site. At each testing site, samples were blended in 25 g portions with 225 mL prewarmed lactose broth until thoroughly homogenized, then allowed to remain at room temperature for 5565 min. Samples were adjusted to a pH of 6.80.2, if necessary, and incubated for 2226 h at 35C. Across the three reporting laboratories, the BAX System detected Salmonella in 10/60 low-spike samples and 58/60 high-spike samples. The reference FDA-BAM method yielded positive results for 11/60 low-spike and 58/60 high-spike samples. Neither method demonstrated positive results for any of the 15 unspiked samples.

Evaluation of the 3M™ Molecular Detection Assay (MDA) 2 – Salmonella for the Detection of Salmonella spp. in Select Foods and Environmental Surfaces: Collaborative Study, First Action 2016.01

2016 ◽  
Vol 99 (4) ◽  
pp. 980-997 ◽  
Author(s):  
Patrick Bird ◽  
Jonathan Flannery ◽  
Erin Crowley ◽  
James R Agin ◽  
David Goins ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Molecular Detection ◽  
Peanut Butter ◽  
Collaborative Study ◽  
Reference Method ◽  
Salmonella Spp ◽  
Inoculum Level ◽  
Test Portion ◽  
Detection Assay ◽  
The U.S

Abstract The 3M™ Molecular Detection Assay (MDA) 2 – Salmonella uses real-time isothermal technology for the rapid and accurate detection of Salmonella spp. from enriched select food, feed, and food-process environmental samples. The 3M MDA 2 – Salmonella was evaluated in a multilaboratory collaborative study using an unpaired study design. The 3M MDA 2 – Salmonella was compared to the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 5 reference method for the detection of Salmonella in creamy peanut butter, and to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook Chapter 4.08 reference method “Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products and Carcass and Environmental Samples” for the detection of Salmonella in raw ground beef (73% lean). Technicians from 16 laboratories located within the continental United States participated. Each matrix was evaluated at three levels of contamination: an uninoculated control level (0 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 obtained for the low inoculum level test portions produced difference in collaborator POD values of 0.03 (95% confidence interval, −0.10 to 0.16) for raw ground beef and 0.06 (95% confidence interval, −0.06 to 0.18) for creamy peanut butter, indicating no statistically significant difference between the candidate and reference methods.

scholarly journals False-Positive Results of Plasma PCR for Cytomegalovirus DNA due to Delayed Sample Preparation

2000 ◽  
Vol 38 (9) ◽  
pp. 3249-3253 ◽  
Author(s):  
Peter Schäfer ◽  
Werner Tenschert ◽  
Matthias Schröter ◽  
Kai Gutensohn ◽  
Rainer Laufs
Keyword(s):  
False Positive ◽  
Room Temperature ◽  
Significant Risk ◽  
Median Number ◽  
Plasma Samples ◽  
Cmv Infection ◽  
Latently Infected ◽  
Positive Results ◽  
Native Plasma ◽  
Cmv Dnaemia

Positive results by cytomegalovirus (CMV) PCR of plasma are considered predictive of active CMV infection in kidney allograft recipients. To assess whether contamination with leukocyte-derived CMV DNA can distort the results, aliquots of whole-blood samples from 60 CMV immunoglobulin G-positive patients with leukocyte CMV DNAemia were stored for up to 24 h at room temperature (RT) and at 4°C before plasma preparation. Native and ultrafiltered plasma samples were tested by CMV and β-globin PCRs. Among 30 latently infected patients (negative for CMV pp65 antigens), low baseline rates (10%) and levels (median number of copies, 10 [per 10 μl]) of CMV plasma DNAemia in native plasma samples increased significantly over time (after 4 h at RT, 37% [P < 0.001]; median number of copies, 45 [P < 0.001]). Similar effects were found during storage at 4°C. Ultrafiltration reduced the levels of CMV plasma DNAemia, but by 6 h of storage the levels were significantly elevated as well. CMV and β-globin DNA kinetics in plasma were parallel. In contrast, 30 actively infected patients (pp65 positive) had high baseline rates (87% in native samples) and levels (median number of copies, 75) of CMV plasma DNAemia. No significant effects of storage or ultrafiltration and no concordance with β-globin DNA kinetics were seen. In conclusion, delayed preparation of plasma samples bears a significant risk of false-positive CMV PCR results, probably due to leukocyte lysis. This has important implications in the clinical setting and for PCR standardization.

scholarly journals Clinical Validation of SensiTest Colistin, a Broth Microdilution-Based Method To Evaluate Colistin MICs

2018 ◽  
Vol 56 (4) ◽  
Author(s):  
Edoardo Carretto ◽  
Flavia Brovarone ◽  
Giuseppe Russello ◽  
Paola Nardini ◽  
Maisra M. El-Bouseary ◽  
...  
Keyword(s):  
Room Temperature ◽  
Susceptibility Testing ◽  
Reference Method ◽  
Multidrug Resistant ◽  
Clinical Validation ◽  
Gram Negative Bacteria ◽  
Broth Microdilution ◽  
Bacterial Strains ◽  
Global Spread ◽  
Severe Infections

ABSTRACT The global spread of multidrug-resistant Gram-negative bacteria has led to the return of colistin for treating severe infections. Recently, different plasmid-mediated genes conferring resistance to this drug were described and reported worldwide. International committees (EUCAST/CLSI) reevaluated inconsistencies surrounding colistin antimicrobial susceptibility testing (AST), concluding that broth microdilution (BMD) should serve as the reference method for AST. The development of an accurate, reproducible commercial test based on BMD is therefore highly desirable. SensiTest Colistin (STC), a BMD-based compact 4-test panel containing the lyophilized antibiotic in 7 2-fold dilutions (0.25 to 16 μg/ml) was here compared with the EUCAST-CLSI standard reference method (BMD) and, for some isolates, with the automated Phoenix 100 system (PHX). A total of 353 bacterial strains were evaluated by two different laboratories; 137 isolates were resistant to colistin (19 were intrinsically resistant, 83 harbored the mcr-1 gene). Essential agreement (EA) between STC and BMD was obtained for 339 out of the 353 strains tested (96.0%). Overall categorical agreement was obtained for 349 out of the 353 strains analyzed (98.9%). Two major errors (MEs; 0.93%) and two very major errors (VMEs; 1.46%) were documented. STC appeared to be a simple but highly reliable test with good reproducibility even with panels stored at room temperature or at 35°C. Moreover, STC showed a good performance with strains carrying the mcr-1 gene, with a 98.8% EA. As the secondary endpoint of our study, VMEs for PHX were documented for 6 isolates (10%).

scholarly journals Validation of iQ-Check E. coli O157:H7 Real-Time PCR Test Kit for Detection of Escherichia coli O157:H7 in Selected Foods

2009 ◽  
Vol 92 (4) ◽  
pp. 1095-1104 ◽  
Author(s):  
Wendy F Lauer ◽  
Sylvie Tymciu ◽  
Caroline D Sidi ◽  
Pierre Sonigo
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Ground Beef ◽  
Reference Method ◽  
Target Sequence ◽  
Apple Cider ◽  
E Coli ◽  
Test Kit ◽  
Significant Difference ◽  
The U.S

Abstract iQ-Check E. coli O157:H7 (Bio-Rad Laboratories, Hercules, CA) is a real-time PCR kit for detection of E. coli O157:H7 from selected foods. Specific fluorescent oligonucleotide probes are used to detect target DNA during the amplification, by hybridizing to the amplicons. These fluorescent probes are linked to a fluorophore which fluoresces only when hybridized to the target sequence. Three foods (ground beef, apple cider, fresh spinach) were selected to compare the performance of iQ-Check E. coli O157:H7 to the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook (MLG) reference method for ground beef and the U.S. Food and Drug Administration/Bacteriological Analytical Manual reference method for apple cider and fresh spinach. Three protocols were tested in this study: a shortened 8 h primary enrichment in buffered peptone water (BPW), a 24 h enrichment in BPW, and an enrichment in appropriate reference method enrichment broth. The iQ-Check E. coli O157:H7 method was able to identify more true/confirmed positive samples than the reference method. Inclusivity and exclusivity rates of the method were 100. iQ-Check E. coli O157:H7 performed as expected when minor procedural variations were introduced, validating the ruggedness of the method. There was no significant difference observed in performance over the shelf life of the kit.

Solving the problem of antibody interference in commercial "sandwich"-type immunoassays of carcinoembryonic antigen.

1989 ◽  
Vol 35 (1) ◽  
pp. 146-151 ◽  
Author(s):  
H J Hansen ◽  
G LaFontaine ◽  
E S Newman ◽  
M K Schwartz ◽  
A Malkin ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Carcinoembryonic Antigen ◽  
False Positive ◽  
Room Temperature ◽  
Murine Monoclonal Antibody ◽  
Heat Extraction ◽  
Normal Individuals ◽  
Sandwich Type ◽  
Commercial Enzyme Immunoassay ◽  
Positive Results

Abstract We evaluated the effect of human anti-murine antibodies (HAMA) on apparent concentrations of carcinoembryonic antigen (CEA) as measured in serum with commercial enzyme immunoassay (EIA) kits manufactured by Abbot ("two-step" double monoclonal antibody assay), Roche, and Hybritech (room-temperature protocol). In sera from patients given parenteral murine monoclonal antibody for experimental diagnostic and immunotherapy studies, HAMA titers were determined with Immunomedics' "ImmuSTRIP HAMA-EIA" kit reagents. "True" CEA titers were established by using the ImmuCEA/MA-EIA and heat-extraction to destroy HAMA before assay for CEA. The concordance of the ImmuCEA/MA assay with the Abbott and Roche CEA EIAs was established with sera from normal individuals and from patients who had not received parenteral injections of murine monoclonal antibody. At high (100 mg/L) concentrations of HAMA, false-positive results were observed with all three kits. The Hybritech and Roche assays were more sensitive to interference by HAMA than was the Abbott CEA-EIA, false-positive results being observed at HAMA concentrations between 1 and 10 mg/L. Similar sensitivity of the three kits to interference by primate anti-MAb sera was demonstrated. Use of primate anti-MAb sera to create controls with HAMA activity and of analyte is recommended to evaluate MAb assays for potential HAMA interference and for use to devise methods to eliminate HAMA interference.

Quantitative Fluorodensitometric Measurement of Aflatoxin B1 with a Flying-Spot Densitometer. II. Comparative Study of B1 Measurements in Spiked and Naturally Contaminated Peanut Products

1972 ◽  
Vol 55 (6) ◽  
pp. 1310-1315
Author(s):  
P R Beljaars ◽  
F H M Fabry ◽  
M M A Pickott ◽  
M J Peeters
Keyword(s):  
Comparative Study ◽  
Silica Gel ◽  
Aflatoxin B1 ◽  
Peanut Butter ◽  
Reference Method ◽  
Amyl Alcohol ◽  
The Other ◽  
Coefficients Of Variation ◽  
Tlc Plates ◽  
Flying Spot

Abstract Peanut butter extracts and samples spiked with 5-40 μg anatoxin B1/kg were analyzed, together with naturally contaminated peanut products, by 3 extraction procedures: the official Dutch method (KB), he Liem et al. method (methanol), and the IUPAC method. The last procedure was selected as a reference method, since it has international application. KB extracts were separated on silica gel G plates with a mixture of chloroform-acetone (90 + 10), whereas IUPAC extracts were separated similarly on MN-G-HR plates. Methanol extracts were resolved on silica gel II plates, using chloroform-trichloroethylene-n-amyl alcohol-formic acid (80 + 15 + 4 + 1) as the developing solvent. After development, plates were scanned with a reflectance flying-spot densitometer. With such techniques, average recoveries for spiked peanut butter extracts ranged from 99 to 105%, with variation values of 11-12%. Recovery values of 69% (KB method) and 84% (methanol and IUPAC methods) were obtained for spiked peanut butter samples. Coefficients of variation ranged from 13 to 15% for fluorodensitometric measurements. Innaturally contaminated peanuts and peanut products , precision values were 13.6% for fluorodensitometric measurements compared to 36% for visual estimations . Both the methanol and IUPAC methods yield extracts suitable for densitometric analysis after spotting on TLC plates; the analytical results obtained are comparable. Extracts from the KB method contained more interfering fluorescent material than the other 2 methods

scholarly journals The Validation of the RIDA®QUICK Gliadin for AOAC Research Institute

2018 ◽  
Vol 101 (5) ◽  
pp. 1548-1557 ◽  
Author(s):  
Markus Lacorn ◽  
Thomas Weiss ◽  
Nicole Klass ◽  
Patrick Bird ◽  
M Joseph Benzinger ◽  
...  
Keyword(s):  
Concentration Level ◽  
Method Comparison ◽  
Probability Of Detection ◽  
Contamination Level ◽  
Stainless Steel Surface ◽  
Comparison Study ◽  
Test Kit ◽  
Corn Products ◽  
Method Comparison Study ◽  
Positive Results

Abstract RIDA®QUICK Gliadin is an immuno-chromatographic test for the detection of gluten in foods, on surfaces, and in Cleaning-in-Place (CIP) waters. This test kit has been adopted as Final Action AOAC INTERNATIONAL Official Methods of AnalysisSM2015.16 for gluten in corn products. The assay is based on the monoclonal antibody R5, which recognizes gluten in wheat, barley, and rye. Four different surfaces were contaminated with a gliadin material and analyzed by a direct swabbing of the surface with the dip-stick. The outcome was an LOD95% concentration of the assay between 1.6 and 3.0 μg/100 cm2 gluten. For CIP waters that contain cleansing reagents, 100% positive results were obtained for minimum gluten concentration between 50 and 100 ng/mL. If the CIP water does not contain these reagents, the minimum detectable gluten level is 10 ng/mL. The independent validation study consisted of a method comparison study of recovery from a CIP solution and from a stainless-steel surface. The test kit was evaluated at six different concentration levels for both matrices, with 20 or 30 replicates per concentration level. The probability of detection was calculated for each contamination level. Additionally, the LOD95% concentration was estimated for each matrix analyzed.

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