Combined Enrichment and Quantitative Polymerase Chain Reaction to Improve Sensitivity and Reduce Time of Detection of Listeria monocytogenes in Mushrooms

This study evaluated a combined method for the detection of in mushrooms, involving enrichment and quantitative real-time polymerase chain reaction (qPCR), to improve sensitivity and reduce detection time. The growth was evaluated in enrichment broth (LEB) with modified carbon and nitrogen sources, increasing sodium concentrations, and added micronutrients. Primers targeting the ( 1 2), ( 1- 6), and ( 1- 4) genes were developed and their sensitivity and specificity were evaluated. The greatest increase in cell count was observed after 6-h incubation at 30°C in LEB+2 × FAC (LEB plus 20 mL/L ferric ammonium citrate), where cell count increased by 1.4 log CFU (colony-forming unit)/mL, compared with 0.9 log CFU/mL in LEB (