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Optimization of a Viability PCR Method for the Detection of Listeria monocytogenes in Food Samples

Agustí, Gemma, Fittipaldi, Mariana, Codony, Francesc
Current microbiology 2018 v.75 no.6 pp. 779-785
DNA, Listeria monocytogenes, food contamination, food pathogens, neutralization, polymerase chain reaction, quality control, rapid methods, viability
Rapid detection of Listeria and other microbial pathogens in food is an essential part of quality control and it is critical for ensuring the safety of consumers. Culture-based methods for detecting foodborne pathogens are time-consuming, laborious and cannot detect viable but non-culturable microorganism, whereas viability PCR methodology provides quick results; it is able to detect viable but non-culturable cells, and allows for easier handling of large amount of samples. Although the most critical point to use viability PCR technique is achieving the complete exclusion of dead cell amplification signals, many improvements are being introduced to overcome this. In the present work, the yield of dead cell DNA neutralization was enhanced by incorporating two new sample treatment strategies: tube change combined with a double light treatment. This procedure was successfully tested using artificially contaminated food samples, showing improved neutralization of dead cell DNA.