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

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.

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

Journal of AOAC International ◽

10.1093/jaoac/92.4.1095 ◽

2009 ◽

Vol 92 (4) ◽

pp. 1095-1104 ◽

Cited By ~ 1

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.

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Evaluation of Applied Biosystems MicroSEQ® Real-Time PCR System for Detection of Salmonella spp. in Food

Journal of AOAC International ◽

10.1093/jaoac/94.4.1106 ◽

2011 ◽

Vol 94 (4) ◽

pp. 1106-1116 ◽

Cited By ~ 9

Author(s):

Priya Balachandran ◽

Yanxiang Cao ◽

Lily Wong ◽

Manohar R Furtado ◽

Olga V Petrauskene ◽

...

Keyword(s):

Real Time ◽

Study Design ◽

Real Time Pcr ◽

Detection System ◽

Peanut Butter ◽

Reference Method ◽

Black Pepper ◽

Salmonella Spp ◽

Culture Methods ◽

Significant Difference

Abstract Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time-to-results compared to traditional culture methods. In this study, the MicroSEQ® real-time PCR system was evaluated for detection of Salmonella spp. in 10 different food matrixes following the AOAC Research Institute's Performance Tested MethodSM validation program. In addition, the performance of the MicroSEQ system was evaluated for the detection of Salmonella in peanut butter as a part of the Emergency Response Validation Program sponsored by the AOAC Research Institute. The system was compared to the ISO 6579 reference method using a paired-study design for detecting Salmonella spp. in raw ground beef, raw chicken, raw shrimp, Brie cheese, shell eggs, cantaloupe, chocolate, black pepper, dry infant formula, and dry pet food. For the peanut butter study, the system was compared to the U.S. Food and Drug Administration's Bacteriological Analytical Manual procedures using an unpaired-study design. No significant difference in performance was observed between the MicroSEQ Salmonella spp. detection system and the corresponding reference methods for all 11 food matrixes. The MicroSEQ system detected all Salmonella strains tested, while showing good discrimination against detection of an exclusivity panel of 30 strains, with high accuracy.

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Singlepath Salmonella

Journal of AOAC International ◽

10.1093/jaoac/92.6.1885 ◽

2009 ◽

Vol 92 (6) ◽

pp. 1885-1889 ◽

Cited By ~ 7

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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iQ-Check Listeria spp. Real-Time PCR Test Kit

Journal of AOAC International ◽

10.5740/jaoacint.govval06 ◽

2013 ◽

Vol 96 (3) ◽

pp. 508-515

Author(s):

Wendy F Lauer ◽

Jean-Philippe Tourniaire

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Reference Method ◽

Sampling Area ◽

Fermented Sausage ◽

Low Level ◽

Test Kit ◽

Significant Difference ◽

High Level ◽

Health Canada

Abstract A comparative evaluation study of the Bio-Rad® iQ-Check™Listeria species Kit (Bio-Rad Laboratories, Hercules, CA) was conducted at Q Laboratories, Inc., Cincinnati, OH. iQ-Check is a rapid method based on real-time PCR amplification and detection of all species of Listeria, including L. grayi, in food and environmental samples. The iQ-Check method was compared to the Health Canada MFHPB-30 reference method for the analysis of five ready-to-eat meats—deli turkey, hot dogs, liver paté, raw fermented sausage, and deli ham—and one stainless steel surface. Each food matrix was analyzed at two contamination levels: a low level at 0.2–2 CFU/25 g and a high level at 2–5 CFU/25 g. The environmental surfaces were analyzed at a low level of 0.2–2 CFU/5 cm2 sampling area and a high level of 2–5 CFU/5 cm2 sampling area. There were 20 replicates per contamination level and five control replicates at 0 CFU/25 g or 0 CFU/5 cm2 sampling area (uninoculated). All samples that were detected by iQ-Check were subsequently confirmed by reference method protocol. There was no significant difference in the number of positive samples detected by the iQ-Check Listeria spp. Kit in comparison to the Health Canada MFHPB-30 method for all matrixes tested.

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TaqMan Salmonella enterica Detection Kit

Journal of AOAC International ◽

10.1093/jaoac/92.6.1895 ◽

2009 ◽

Vol 92 (6) ◽

pp. 1895-1901 ◽

Cited By ~ 4

Author(s):

Robert S Tebbs ◽

Yan Y Cao ◽

Priva Balachandran ◽

Olga Petrauskene ◽

Thomas Hammack

Keyword(s):

Salmonella Enterica ◽

Peanut Butter ◽

Reference Method ◽

Test Design ◽

Chi Square ◽

Independent Laboratory ◽

Sample Enrichment ◽

Peptone Water ◽

Chi Square Analysis ◽

Sensitivity Specificity

Abstract Peanut butter spiked with Salmonella enterica ser. Typhimurium was prepared by an independent laboratory and sent to Applied Biosystems to determine the sensitivity and specificity of the TaqMan Salmonella enterica Detection Kit for detecting Salmonella in peanut butter. The samples were spiked at three levels: five no-spike (0 CFU/25 g); 20 low-spike (0.2 CFU/25 g); and 20 high-spike (2 CFU/25 g). They were coded to create a blind set of 45 samples. The samples were processed based on an unpaired test design that included enrichment in buffered peptone water for the candidate method and lactose broth for the reference method. In the candidate method, a 1 mL aliquot of enriched sample was extracted using PrepMan Ultra Sample Preparation Reagent; the sample was amplified on the Applied Biosystems 7500 real-time PCR system, and analyzed for detection of Salmonella using RapidFinder Version 1.0 software. All samples processed by the candidate method were confirmed by culture according to the U.S. Food and Drug Administration's Bacteriological Analytical Manual procedures. Sensitivity, specificity, and Chi-square analysis were calculated by combining candidate method results with those of the reference method that were collected by the independent laboratory. The TaqMan Salmonella enterica Detection Kit showed 40 sensitivity, 100 specificity, and a Chi-square value equal to 1.52. Chi-square analysis indicated the candidate method and the reference method were comparable. Although the candidate method sensitivity was only 40 when compared with the reference method (unpaired samples), the sensitivity was >100 when the candidate method results were compared with those of the confirmation method (same sample enrichment).

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Evaluation of Applied Biosystems MicroSEQ® Real-Time PCR System for Detection of Listeria spp. in Food and Environmental Samples

Journal of AOAC International ◽

10.5740/jaoacint.11-311 ◽

2012 ◽

Vol 95 (4) ◽

pp. 1074-1083 ◽

Cited By ~ 4

Author(s):

Olga V Petrauskene ◽

Yanxiang Cao ◽

Patrick Zoder ◽

Lily Y Wong ◽

Priya Balachandran ◽

...

Keyword(s):

Stainless Steel ◽

Sample Preparation ◽

Real Time ◽

Real Time Pcr ◽

Reference Method ◽

Test Method ◽

Stainless Steel Surface ◽

Acid Extraction ◽

Chi Square ◽

Chi Square Analysis

Abstract A complete system for real-time PCR detection of Listeria species was validated in five food matrixes and five environmental surfaces, namely, hot dogs, roast beef, lox (smoked salmon), pasteurized whole cow's milk, dry infant formula, stainless steel, plastic cutting board, ceramic tile, rubber sheets, and sealed concrete. The system consists of the MicroSEQ®Listeria spp. Detection Kit, two sample preparation kits (PrepSEQ® Nucleic Acid Extraction Kit and PrepSEQ Rapid Spin Sample Preparation Kit), the Applied Biosystems 7500 Fast Real-Time PCR instrument, and the RapidFinder™ Express v1.1 Software for data analysis. The test method was compared to the ISO 11290-1 reference method using an unpaired study design. The MicroSEQ Listeria spp. Detection Kit and the ISO 11290-1 reference method showed equivalent detection based on Chi-square analysis for all matrixes except hot dogs. For hot dogs, the MicroSEQ method detected more positives than the reference method for the low- and high-level inoculations, with all of the presumptive positives confirmed by the reference method. An independent validation study confirmed these findings on lox and stainless steel surface. The MicroSEQ kit detected all 50 Listeria strains tested and none of the 31 nontarget bacteria strains.

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RapidChek SELECT Salmonella

Journal of AOAC International ◽

10.1093/jaoac/92.6.1890 ◽

2009 ◽

Vol 92 (6) ◽

pp. 1890-1894 ◽

Cited By ~ 8

Author(s):

Mark T Muldoon ◽

Jingkun Li ◽

Meredith Sutzko ◽

Ann Christine Olsson-Allen ◽

George Teaney ◽

...

Keyword(s):

False Positive Rate ◽

Peanut Butter ◽

False Negative ◽

False Negative Rate ◽

Reference Method ◽

Salmonella Spp ◽

Chi Square ◽

Negative Results ◽

Significant Difference ◽

Positive Rate

Abstract RapidChek SELECT Salmonella was previously validated in the Performance Tested MethodsSM program for the detection of Salmonella spp. in raw ground chicken, chicken carcass rinse, sliced cooked turkey, and liquid eggs. The present matrix extension study conducted under the AOAC Research Institute Emergency Response Validation program compared the RapidChek SELECT Salmonella method to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) method for the detection of Salmonella Typhimurium in peanut butter. Overall, 27 samples were found positive by the RapidChek SELECT Salmonella method and 27 were found to be positive by the reference method. All RapidChek SELECT Salmonella presumptive positives were confirmed positive by the cultural reference method; additionally, all presumptive negative results were confirmed negative by the cultural reference method. Accordingly 0 false-negative rate and 0 false-positive rate were found. No significant difference between the RapidCheck SELECT Salmonella and FDA-BAM reference method was found; calculated Chi-square was 0. Results indicate that a low level of Salmonella in peanut butter can be successfully recovered and detected in the minimum 24 h enrichment protocol.

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Reveal® Salmonella Enteritidis Test for Detection of Salmonella Enteritidis in Shell Eggs and Environmental Samples

Journal of AOAC International ◽

10.1093/jaoac/94.4.1125 ◽

2011 ◽

Vol 94 (4) ◽

pp. 1125-1137 ◽

Cited By ~ 2

Author(s):

Balamurugan Jagadeesan ◽

Stephanie Curry ◽

Debra Foti ◽

Lauren Peterson ◽

Rebecca Wilson ◽

...

Keyword(s):

Environmental Samples ◽

Salmonella Enteritidis ◽

Reference Method ◽

Salmonella Enterica Serovar Enteritidis ◽

Chi Square ◽

Reference Procedure ◽

Shell Eggs ◽

Enrichment Procedure ◽

Significant Difference ◽

Chi Square Analysis

Abstract Reveal®Salmonella Enteritidis (SE) is a lateral flow-based immunodiagnostic assay used for rapid detection of Salmonella enterica serovar Enteritidis from pooled shell eggs and environmental samples. This assay uses highly specific antibodies to accurately detect S. Enteritidis. Studies were conducted to compare the performance of this test against reference procedures for detection of S. Enteritidis from both pooled shell eggs and environmental samples. Pooled shell eggs were inoculated with low levels of S. Enteritidis and were enriched according to the procedure prescribed by the U.S. Food and Drug Administration. Uninoculated samples were included in each trial. Reveal SE exhibited 100% sensitivity and 100% specificity in comparison to the reference method in all trials. An abbreviated 48 h/(no hold) enrichment procedure was also developed and validated for detection of S. Enteritidis from pooled shell egg samples. This shortened enrichment procedure can be used in conjunction with the Reveal SE test and offers a significant enrichment time savings of 96 h. Chi-square analysis revealed that there was no significant difference between the abbreviated Reveal method and the reference procedure for detection of S. Enteritidis from pooled shell egg samples. Out of 245 natural drag swabs screened internally, only three samples tested Reveal SE positive and were confirmed by the reference procedure, resulting in 100% sensitivity and 100% specificity. An external laboratory screened 147 poultry house environmental samples and obtained 35 Reveal SE confirmed positives for Reveal SE sensitivity of 100% and specificity of 90%. Inoculation trials with drag swabs resulted in 96% sensitivity and 100% specificity. Thus, these data demonstrate that Reveal SE is a highly sensitive and specific assay for the detection of S. Enteritidis from both pooled shell eggs and environmental samples.

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

Journal of AOAC International ◽

10.5740/jaoacint.cs2011_03 ◽

2011 ◽

Vol 94 (6) ◽

pp. 1821-1834 ◽

Cited By ~ 4

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.

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Comparison of ELISA and RT-PCR assays for the detection of Tomato spotted wilt virus in peanut

Peanut Science ◽

10.3146/ps08-024.1 ◽

2009 ◽

Vol 36 (2) ◽

pp. 133-137 ◽

Cited By ~ 1

Author(s):

P. M. Dang ◽

D. L. Rowland ◽

W. H. Faircloth

Keyword(s):

Tomato Spotted Wilt Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Infection Rates ◽

Rt Pcr ◽

Chi Square ◽

Tomato Spotted Wilt ◽

Significant Difference ◽

Pcr Assays ◽

Chi Square Analysis ◽

Wilt Virus

Abstract Diagnosis of Tomato spotted wilt virus (TSWV) in peanut can be accomplished by enzyme-linked immunosorbent assay (ELISA) or reverse transcription polymerase chain reaction (RT-PCR) but there has been no report of a direct comparison of the success of the two assays in evaluating infection rates of field-grown peanut. We collected peanut root samples from field-grown plants, 76 in 2006 and 48 in 2007, and tested these samples by both ELISA and RT-PCR assays for the presence of TSWV. Out of 124 samples, 50 (40.3%) and 57 (46.0%) were positive for TSWV by ELISA and RT-PCR respectively. In 13.7% of these samples, ELISA and RT-PCR differed in their results. However, Chi square analysis showed no significant difference between the results for these two assays. This result supports the conclusion that ELISA and RT-PCR are comparable for detecting TSWV infection rates in field-grown peanuts.

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