scholarly journals Evaluation of the Solus One Listeria Method for the Detection of Listeria Species on Environmental Surfaces

2019 ◽  
Vol 102 (2) ◽  
pp. 570-579
Author(s):  
Elizabeth Tonner ◽  
Siobhan Kelly ◽  
Simon Illingworth ◽  
Nevin Perera ◽  
Benjamin Bastin ◽  
...  

Abstract Background: Solus One Listeria is designed to accurately detect Listeria species (Listeria grayi, L. innocua, L. ivanovii, L. marthii, L. monocytogenes, L. seeligeri, and L. welshimeri) from stainless steel and plastic environmental surface matrixes using an antibody-based technology test system paired with proprietary SOLO+ media and combined with manual or automated sample preparation method. Objective: Solus One Listeria was evaluated for inclusivity and exclusivity and a matrix comparison study fortwo environmental surfaces. Methods: Solus One Listeria was comparedwith the following reference method for the method comparison study: the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 10 from stainless steel and plastic environmental surfaces. Both the manual and automatedpreparation methods were performed for stainless steel and plastic environmental surfaces. Results: For the inclusivity and exclusivityevaluation, Solus One Listeria correctly identified all 50 target organism isolates and correctly excluded all 30 nontarget strains that were analyzed. In the method comparison study, bothSolus One Listeria manual and automated preparation methods demonstrated no significant differences based on probability of detection statistical analysis between presumptive and confirmed results or between candidate and reference methodresults for two environmental surfaces after 22–30 h of enrichment time. Probability of detection analysis of Solus One Listeria method robustness, product consistency (lot-to-lot), and stability studies using the automated preparation method demonstrated no statistically significant differences. Conclusions: The data from the study support the product claims of Solus One Listeria for the accurate detection of Listeria species, using both the manual and automated methods (using theDynex DS2 instrument), on both environmental surfaces analyzed.

2017 ◽  
Vol 100 (5) ◽  
pp. 1434-1444 ◽  
Author(s):  
Adam C Joelsson ◽  
Shawn P Terkhorn ◽  
Ashley S Brown ◽  
Amrita Puri ◽  
Benjamin J Pascal ◽  
...  

Abstract Veriflow®Listeria species (Veriflow LS) is a molecular-based assay for the presumptive detection of Listeria spp. from environmental surfaces (stainless steel, sealed concrete, plastic, and ceramic tile) and ready-to-eat (RTE) food matrixes (hot dogs and deli meat). The assay utilizes a PCRdetection method coupled with a rapid, visual, flow-based assay that develops in 3 min post-PCR amplification and requires only a 24 h enrichment for maximum sensitivity. The Veriflow LS system eliminates the need for sample purification, gel electrophoresis, or fluorophore-based detection of target amplification and does not require complex data analysis. This Performance Tested MethodSM validation study demonstrated the ability of the Veriflow LS assayto detect low levels of artificially inoculated Listeria spp. in six distinct environmental and food matrixes. In each unpaired reference comparison study, probability of detection analysis indicated that there was no significant difference between the Veriflow LS method and the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guide Chapter 8.08 reference method. Fifty-one strains of various Listeria spp. were detected in the inclusivity study, and 35 nonspecific organisms went undetected in the exclusivity study. The study results show that the Veriflow LS is a sensitive, selective, and robust assay for the presumptive detection of Listeria spp. sampled from environmental surfaces (stainless steel, sealed concrete, plastic, and ceramic tile) and RTE food matrixes (hot dogs and delimeat).


2020 ◽  
Vol 103 (3) ◽  
pp. 833-842
Author(s):  
John Bodner ◽  
Mike Toribo ◽  
Erin Carruthers ◽  
Michael Weber ◽  
Holly Urquhart ◽  
...  

Abstract Background CERTUS Environmental Listeria species Detection Kit (CERTUS EL Detection Kit) is a real-time, bio-contained assay designed to accurately detect Listeria species (L. grayi, L. innocua, L. ivanovii, L. marthii, L. monocytogenes, L. seeligeri, and L. welshimeri) from environmental surface matrixes using an antibody-coupled magnetic microparticle with a Surface Enhanced Raman Spectroscopy (SERS) nanoparticle technology test system paired with proprietary CERTUS EL Selective Growth Media and CERTUS Detection Unit. Objective The method was evaluated for AOAC®Performance Tested MethodSM certification. Methods Inclusivity and exclusivity, matrix studies, product consistency and stability were conducted to evaluate the CERTUS EL Detection Kit. Results In the matrix studies, stainless steel, ceramic tile, plastic (polystyrene) and sealed concrete environmental surfaces (4 × 4” test areas) were tested. No statistically significant differences were found by Probability of Detection analysis (POD) in any of the matrixes when results were compared to the U.S. Food and Drug Administration cultural microbiology reference method for Listeria. The CERTUS EL Detection Kit correctly identified all 50 target Listeria isolates and correctly excluded all 30 non-target strains that were analyzed. Probability of Detection analysis of CERTUS EL Detection Kit robustness, product consistency (lot-to-lot) and stability studies demonstrated no statistically significant differences, and no variation was observed between instruments. Conclusions The data collected in these studies demonstrate that the CERTUS EL Detection Kit is a reliable method for the rapid and specific detection of Listeria from stainless steel, ceramic tile, plastic (polystyrene) and sealed concrete environmental surfaces.


2020 ◽  
Vol 103 (1) ◽  
pp. 216-222
Author(s):  
Nicole Klass ◽  
Benjamin Bastin ◽  
Erin Crowley ◽  
James Agin ◽  
Mike Clark ◽  
...  

Abstract Background: The Bio-Rad iQ-Check Listeria spp. Kit uses real-time PCR technology for detection of Listeria species in select food matrixes and environmental surfaces. Objective: The iQ-Check Listeria spp. method was modified to reduce the enrichment medium volume for environmental sponges from 225 and 100 to 60 mL and to reduce the enrichment time for sponges and swabs from 25 ± 1 to as short as 18 h. The modified method was validated with stainless steel, polystyrene plastic, and sealed concrete using sponges or swabs with two different neutralizing buffers (Letheen Broth and HiCap™ Neutralizing Broth). In addition, the Bio-Rad Free DNA Removal Solution was used for all environmental samples. Methods: The iQ-Check Listeria spp. modified method was compared with the reference culture method in the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook Chapter 8.10 using an unpaired study design. Results: In the method comparison study, the iQ-Check Listeria spp. modified method demonstrated no statistical difference in performance between candidate and reference method results or between presumptive and confirmed results for all environmental surfaces analyzed using HiCap Neutralizing Broth (World Bioproducts LLC) and Letheen broth. Conclusions: The modified iQ-Check Listeria spp. method is an effective method for the detection of Listeria species in environmental surfaces using both types of neutralizing buffer. Highlights: The method modification was granted based on the data collected.


2018 ◽  
Vol 101 (5) ◽  
pp. 1548-1557 ◽  
Author(s):  
Markus Lacorn ◽  
Thomas Weiss ◽  
Nicole Klass ◽  
Patrick Bird ◽  
M Joseph Benzinger ◽  
...  

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.


2018 ◽  
Vol 101 (5) ◽  
pp. 1490-1507
Author(s):  
Gregory Juck ◽  
Verapaz Gonzalez ◽  
Ann-Christine Olsson Allen ◽  
Meredith Sutzko ◽  
Kody Seward ◽  
...  

Abstract The Romer Labs RapidChek®Listeria monocytogenes test system (Performance Tested Method 011805) was validated against the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook (USDA-FSIS/MLG), U.S. Food and Drug Association Bacteriological Analytical Manual (FDA/BAM), and AOAC Official Methods of Analysis (AOAC/OMA) cultural reference methods for the detection of L. monocytogenes on selected foods including hot dogs, frozen cooked breaded chicken, frozen cooked shrimp, cured ham, and ice cream, and environmental surfaces including stainless steel and plastic in an unpaired study design. The RapidChek method uses a proprietary enrichment media system, a 44–48 h enrichment at 30 ± 1°C, and detects L. monocytogenes on an immunochromatographic lateral flow device within 10 min. Different L. monocytogenes strains were used to spike each of the matrixes. Samples were confirmed based on the reference method confirmations and an alternate confirmation method. A total of 140 low-level spiked samples were tested by the RapidChek method after enrichment for 44–48 h in parallel with the cultural reference method. There were 88 RapidChek presumptive positives. One of the presumptive positives was not confirmed culturally. Additionally, one of the culturally confirmed samples did not exhibit a presumptive positive. No difference between the alternate confirmation method and reference confirmation method was observed. The respective cultural reference methods (USDA-FSIS/MLG, FDA/BAM, and AOAC/OMA) produced a total of 63 confirmed positive results. Nonspiked samples from all foods were reported as negative for L. monocytogenes by all methods. Probability of detection analysis demonstrated no significant differences in the number of positive samples detected by the RapidChek method and the respective cultural reference method.


2012 ◽  
Vol 95 (3) ◽  
pp. 850-859 ◽  
Author(s):  
Mark T Muldoon ◽  
Anne-Christine Olsson Allen ◽  
Vera Gonzales ◽  
Meredith Sutzko ◽  
Klaus Lindpaintner

Abstract The SDIX RapidChekTMListeria F.A.S.T. test system was validated against the U. S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) cultural reference method for the detection of Listeria species on stainless steel, plastic, rubber, and painted concrete. The SDIX method uses a proprietary RapidChek Listeria enrichment media for a one-step, 24–40 h enrichment at 30°C, and detects Listeria on an immunochromatographic lateral flow device in 10 min. Different Listeria species were used to spike each of the environmental surfaces. Environmental surfaces were spiked at levels ranging from 50 to 400 CFU/surface (1 in.2 swabs for painted concrete, 4 in.2 for sponge). A total of 120 spiked samples were tested by the SDIX method at 24 and 40 h and the cultural reference method. Total confirmed positives were 49, 54, and 48 for the SDIX 24 h method, the SDIX 40 h method, and the USDA-FSIS cultural reference method, respectively. Nonspiked samples from all environmental surfaces were reported as negative for Listeria spp. by all methods. The overall Chi square was 0.017 (P = 0.104) and 0.611 (P = 0.566) after a 24 and 40 h enrichment, respectively, indicating that the test method was equivalent in performance to the reference method at both enrichment times. The SDIX method was evaluated for the detection of 50 Listeria and 35 non-Listeria bacterial strains. All 50 Listeria strains were detected by the method (100% sensitivity). Five out of 35 non-Listeria species gave light test signals when grown in nonselective broth culture and tested undiluted. However, when grown in the RapidChek Listeria F.A.S.T. proprietary media, only one bacterial strain (Staphylococcus aureus) was detected, giving a very low test signal (97% specificity). The method was shown to be robust toward several alterations in testing and storage conditions.


2018 ◽  
Vol 101 (2) ◽  
pp. 562-576
Author(s):  
Brett Maroni ◽  
Tucker Lopez ◽  
Cambria Neal ◽  
Sarah Verver ◽  
Celina Puente ◽  
...  

Abstract Two candidate method modifications for the Atlas Listeria Environmental LE Detection Assay were compared with the U.S. Department of Agriculture (USDA)-Food Safety and Inspection Service Microbiology Laboratory Guidebook 8.09 (MLG 8.09) method for detection of Listeria spp. on stainless steel, polyvinyl chloride (PVC), and sealed concrete surfaces. For LE candidate method 1, samples were enriched in FoodChek Actero Listeria Enrichment Media [ALEM; Performance Tested MethodSM (PTM) 111201] at 35 ± 2°C for 18 to 24 h and evaluated for a range of analytical sample volumes. For LE candidate method 2, the current Roka PTM using 90 mL of Half-Fraser broth for enrichment at 35 ± 2°C was evaluated at 24 h with a reduced sample volume. These comparisons were made in multiple studies across the three environmental surfaces. Within each method and study, a total of 5 samples were uninoculated, 20 samples were inoculated with Listeria spp. at a low level to target fractional positivity, and 5 samples were inoculated with Listeria spp. at a high level to approach a probability of detection of 1. Inclusivity and exclusivity studies were also conducted for the LE method in combination with Half-Fraser and ALEM. The Atlas Listeria Environmental LE Detection Assay detected all 50 inclusive organisms, including 25 strains of L. monocytogenes and 5 strains of each of the other five common species of Listeria (L. innocua, L. welshimeri, L. ivanovii, L. seeligeri, and L. grayi) and none of the 30 exclusive organisms across all media and with both 200 and 2000 µL sample volumes. For the LE candidate method 1 studies, no significant differences were observed within the Roka ALEM method at 18, 20, or 24 h and for both the 200 and 2000 µL sample volumes as compared with the paired culture outcome. However, the ALEM method performed significantly better as compared with the unpaired reference method for sealed concrete and stainless steel. For the LE candidate method 2 studies, no significant differences were observed within the Roka HF method at 24 h for the 200 and 2000 µL samples as compared with the paired culture outcomes and unpaired reference method outcomes across the surfaces. The independent laboratory studies observed no significant differences in performance between the USDA/MLG 8.09 reference method and candidate methods 1 or 2, respectively, across the evaluated parameters. Overall, the candidate method 1 modification parameters and candidate method 2 sample parameters for the Atlas Listeria Environmental LE Detection Assay were statistically equivalent to or better than the reference method for detection of Listeria spp. on stainless steel, PVC, and sealed concrete surfaces, providing greater flexibility in method application for end users.


2019 ◽  
Vol 102 (4) ◽  
pp. 1145-1161
Author(s):  
David Higgins ◽  
Holly Urquhart ◽  
Siobhan Kelly ◽  
Simon Illingworth ◽  
Nevin Perera ◽  
...  

Abstract Background: Solus One Salmonella is designed to accurately detect Salmonella species (Salmonella enterica subspecies enterica, salamae, arizonae, diarizonae, houtenae, indica, and Salmonella bongori) from select food matrixes and stainless-steel and plastic environmental surfaces. Solus One Salmonella uses an antibody-based technology test system that is paired with media and our proprietary media supplement, the Solus One Salmonella supplement combined with a manual or automated sample preparation method. Objective: Solus One Salmonella was evaluated for inclusivity and exclusivity, and a matrix comparison study was done for six food matrixes (raw beef trim, pasteurized liquid egg, raw salmon, cheddar cheese, Romaine lettuce, nonfat dry milk) and two environmental surfaces (stainless steel and polystyrene). Methods: Solus One Salmonella was compared with the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 5: Salmonella (July 2018) and the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Manual, 4.09 (January 2017) in the matrix study. Both the manual and automated sample preparation methods were performed for cheddar cheese and stainless-steel environmental surfaces. Results: For the inclusivity and exclusivity evaluation, Solus One Salmonella correctly detected all 108 target organism isolates and correctly excluded all 35 nontarget strains that were analyzed. Conclusions: In the method comparison study, both Solus One Salmonella manual and automated sample preparation methods demonstrated no significant differences based on probability of detection (POD) statistical analysis between presumptive and confirmed results or between candidate and reference method results for the six food matrixes after 20–22 h and two environmental surfaces after 16–20 h of enrichment time. POD analysis of Solus One Salmonella method robustness, product consistency, and stability studies using the automated sample preparation method demonstrated no statistically significant differences.


2020 ◽  
Vol 58 (7) ◽  
Author(s):  
Stephen Jenkins ◽  
Nathan A. Ledeboer ◽  
Lars F. Westblade ◽  
Carey-Ann D. Burnham ◽  
Matthew L. Faron ◽  
...  

ABSTRACT NG-Test Carba 5 is a rapid in vitro multiplex immunoassay for the phenotypic detection and differentiation of five common carbapenemase families (KPC, OXA-48-like, VIM, IMP, and NDM) directly from bacterial colonies. The assay is simple to perform and has recently received U.S. Food and Drug Administration clearance. A method comparison study was performed at geographically diverse medical centers (n = 3) in the United States, where 309 Enterobacterales and Pseudomonas aeruginosa isolates were evaluated by NG-Test Carba 5 (NG Biotech, Guipry, France), the Xpert Carba-R assay (Cepheid, Inc., Sunnyvale, CA), the modified carbapenem inactivation method (mCIM), the EDTA-modified carbapenem inactivation method, and disk diffusion with carbapenems. Colonies from tryptic soy agar with 5% sheep blood (blood agar) and MacConkey agar were tested, and the results were compared to those obtained by a composite reference method. Additionally, a fourth medical center performed a medium comparison study by evaluating the performance characteristics of NG-Test Carba 5 from blood, MacConkey, and Mueller-Hinton agars with 110 isolates of Enterobacterales and P. aeruginosa. These results were compared to the expected genotypic and mCIM results. For the multicenter method comparison study, the overall positive percent agreement (PPA) and the overall negative percent agreement (NPA) of NG-Test Carba 5 with the composite reference method were 100% for both blood and MacConkey agars. The medium comparison study at the fourth site showed that the PPA ranged from 98.9% to 100% and that the NPA ranged from 95.2% to 100% for blood, MacConkey, and Mueller-Hinton agars. NG-Test Carba 5 accurately detected and differentiated five common carbapenemase families from Enterobacterales and P. aeruginosa colonies on commonly used agar media. The results of this test will support a streamlined laboratory work flow and will expedite therapeutic and infection control decisions.


Author(s):  
Ronald Johnson ◽  
John Mills ◽  
Jean-Louis Pittet ◽  
Olivier Mathia ◽  
Patrick Bird ◽  
...  

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.


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