P2-56 Parallel Study Comparing Conventional ISO 11290-1 and 3M Molecular Detection Assay 2 Listeria monocytogenes for the Detection of Listeria monocytogenes in Chicken Meat and Its Processing Plant Environment, in Thailand

Tuesday, August 2, 2016
America's Center - St. Louis
Paninee Mongkolsuk, Mahidol University, Bangkok, Thailand
Soraya Chaturongakul, Mahidol University, Bangkok, Thailand
Bhinyada Ngamwongsatit, Mahidol University, Bangkok, Thailand
Janejira Fuangpaiboon, 3M Food Safety, 3M Thailand Ltd., Bangkok, Thailand
Saengrawee Jongvanich, 3M Food Safety, 3M Thailand Ltd., Bangkok, Thailand
Panida Pisaisawat, 3M Food Safety, 3M Thailand Ltd., Bangkok, Thailand
Introduction: Listeria monocytogenes is a foodborne bacterial pathogen associated with life-threatening invasive diseases in humans and animals. It is also among the top causes of food recalls worldwide. Listeria monocytogenes is a threat to both public health and food industry. Early detection of Listeria monocytogenes contamination can save lives and prevent recalls.

Purpose: This study aimed to evaluate the 3M Molecular Detection Assay 2  Listeria monocytogenes (3M MDA 2 Listeria monocytogenes) in comparison to the conventional ISO 11290-1 method.

Methods: Sixty 25-gram chicken meat samples and 60 environmental samples (sponge sticks) were collected from chicken processing plants. Additionally (n=49) chicken meat and (n=50) sponge with letheen broth samples were artificially inoculated with Listeria monocytogenes using 200, 20, 2, 0.2, and 0.02 CFU/sample to determine the each method’s sensitivity. Duplicate sets of each sample were screened for Listeria monocytogenes using ISO 11290-1 and 3M MDA 2 Listeria monocytogenes. PCR targeting the genus specific prsA and species specific hly genes and sequencing were used on presumptives to confirm genus and species.  

Results: Of the 120 naturally contaminated samples, 6 and 7 samples were positive for Listeria monocytogenes by ISO 11290-1 and 3M MDA 2 Listeria monocytogenes, respectively. Of the 109 chicken meat samples, 3M MDA 2 Listeria monocytogenes detected Listeria monocytogenes with 96.33% relative accuracy, 98.85% relative specificity, and 86.36% relative sensitivity on naturally and artificially contaminated samples. In the 110 sponge samples, relative accuracy, specificity, and sensitivity were 97.27%, 96.97%, and 100%, respectively. The detection limit was < 2 CFU.

Significance: This study demonstrates that compared to ISO 11290-1, the 3M MDA 2 Listeria monocytogenes is reliable and accurate and at the same time this rapid molecular detection assay offers a faster time to result in the detection of Listeria monocytogenes in food processing.