Harnessing the sensitivity and specificity of innate immune receptors to identify food contaminants 

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Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B911
Abstract ID: 5251

Presenting Author:
Junela Cecille S Hunat , Master's Student at Towson Univ.

Abstract:

Approximately 42% of food recalls issued by the U.S. Food and Drug Administration (FDA) annually are due to bacterial contaminations. The current industry-standard method to detect contamination, mass spectrometry (MS), requires improvement to detect contaminants at a lower threshold. We hypothesize that a cell-based TLR reporter colorimetric assay offers a more cost-effective and efficient way to detect food contaminants at concentrations lower than those achievable with MS. Using HEK293 reporter cells engineered to express murine TLRs and a downstream secreted embryonic alkaline phosphatase (SEAP) under the NF-κB promoter, the presence of food contaminants was detected based on the color change observed in the supernatant, and the concentration of SEAP was quantified using a microplate spectrophotometer. This assay was first used to determine the background level concentration of TLR activation in uncontaminated food samples including romaine lettuce, salmon, organic cheddar cheese, and deli meat. Subsequently, we incubated the food homogenates with known amounts of heat-killed bacteria, including Escherichia coli and Staphylococcus spp., ranging from 1 ug/mL to 0.1 ng/mL to establish precise detection thresholds. Using HEK-Blue mTLR4 and hTLR2 cells, we were able to detect contaminations at a concentration as low as 10 ng/ml and 10⁶ cells/ml, respectively.​ Our assay was able to reliably detect a lower concentration of contaminants than what MS can currently detect.