Modification of the Bio-Rad iQ-Check <i>Listeria</i> spp. Kit for the Detection of <i>Listeria</i> Species in Environmental Surfaces

Listeria monocytogenes is the third most deadly foodborne pathogen in the United States. The bacterium is found in soil and water, contaminating raw food products and the processing environment, where it can persist for an extended period. Currently, testing of food contact and non-food contact surfaces is performed using an array of sampling devices and endpoint technologies, offering various levels of sensitivity, cost, user skill, and time to detection. Paper-based microfluidic devices (µPADs) are a rapid detection platform amenable to low-cost, user-friendly, and portable diagnostics. In this study, we developed and evaluated a µPAD platform specific for the colorimetric detection of the Listeria genus following recovery from food contact and non-food contact surfaces. For detection, four colorimetric substrates specific for the detection of β-glucosidase, two broths selective for the detection of Listeria spp., and a nonselective broth were evaluated to facilitate detection of Listeria spp. The limit of detection and time to detection were determined by using pure bacterial cultures. After 8 h enrichment, L. monocytogenes (102 Colony Forming Units (CFU)/coupon) was detected on every surface. After 18 h enrichment, L. monocytogenes (102 CFU/coupon) was detected on all surfaces with all swabbing devices. This study demonstrated the ability of the µPAD-based method to detect potentially stressed cells at low levels of environmental contamination.

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“…Our results from this study are comparative to Klass et al [ 21 ]. In their study, the Bio-Rad iQ Check Listeria spp.…”

Section: Discussionsupporting

confidence: 65%

Development and Evaluation of a Paper-Based Microfluidic Device for Detection of Listeria monocytogenes on Food Contact and Non-Food Contact Surfaces

Broten

Wydallis

Reilly

et al. 2022

Foods

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Comparison of Roka Atlas® System Performance and Health Canada Reference Method for Listeria Detection From Plastic, Sealed Concrete, and Stainless-Steel Surface Samples

Forghani,

Themeli,

Mai

et al. 2024

Journal of AOAC International

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Background There is a high demand in food industry and public health for rapid automated methods capable of high volume sample processing. Objective In an unpaired study Roka Atlas® System performance was compared with Health Canada reference method MFHPB-30 for Listeria spp. (LSP Roka assay) and Listeria monocytogenes (LmG2 Roka Assay) detection on plastic (PL), sealed concrete (SC), and stainless steel (SS) surfaces (45 samples each per candidate or reference method). Methods Seeking shorter enrichment time for the candidate method, R2 medium pre-enrichment for 14, 16, and 24 h at 35 °C was combined with the Roka assay. Listeria welshimeri, L. innocua, and L. monocytogenes were employed to individually inoculate each of the three surfaces, with two competing microorganisms within the 10–100 fold higher concentration range. Results False negative, false positive, sensitivity and specificity were 0, 0, 100, and 100%, respectively, for the plastic, sealed concrete, and stainless steel surfaces, regardless of inoculation level (high, low, and uninoculated) and enrichment time. Candidate method detected 10, 7 and 9 true positives, versus 10, 6 and 10 by the reference method in individually inoculated SS, PL and SC, respectively. Conclusion Probability of detection for all the three surfaces for the Roka Atlas® System was comparable to the reference method, in this unpaired study. Highlights The Roka Atlas® System detected targets after as little as 14 h enrichment. Surface type did not negatively affect assay sensitivity or specificity. The Roka Atlas® System was comparable to the reference method.

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Modification of the Bio-Rad iQ-Check Listeria spp. Kit for the Detection of Listeria Species in Environmental Surfaces

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Development and Evaluation of a Paper-Based Microfluidic Device for Detection of Listeria monocytogenes on Food Contact and Non-Food Contact Surfaces

Development and Evaluation of a Paper-Based Microfluidic Device for Detection of Listeria monocytogenes on Food Contact and Non-Food Contact Surfaces

Comparison of Roka Atlas® System Performance and Health Canada Reference Method for Listeria Detection From Plastic, Sealed Concrete, and Stainless-Steel Surface Samples

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