Evaluation of Environmental Sampling Methods and Rapid Detection Assays for Recovery and Identification of Listeria spp. from Meat Processing Facilities

• Published in: Journal of food protection 2009-04, Vol.72 (4), p.696-701
• Main Authors: Kovacevic, Jovana, Bohaychuk, Valerie M, Barrios, Pablo Romero, Gensler, Gary E, Rolheiser, Deana L, McMullen, Lynn M
• Format: Article
• Language: English
• Subjects: Automation; Bacteria; bacterial contamination; Bacteriology; Biological and medical sciences; Cotton; environment; Environmental Microbiology; Environmental monitoring; Equipment Contamination; Facilities; Food; Food Contamination - prevention & control; Food industries; Food Microbiology; food pathogens; Food safety; Food-Processing Industry - standards; Fundamental and applied biological sciences. Psychology; General aspects; Listeria; Listeria - classification; Listeria - isolation & purification; Meat; Meat - microbiology; meat packing plants; Meat processing; Methods; Methods of analysis, processing and quality control, regulation, standards; microbial detection; Microorganisms; polymerase chain reaction; precipitin tests; rapid methods; Reproducibility of Results; Sampling methods; Sampling techniques; Sanitation; Sensitivity and Specificity; Software
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-72.4.696

Studies that isolated Listeria spp. from the environment of two meat processing facilities were conducted. Samples were collected in the processing environment of the facilities with three different sampling methods (cotton swab, sterile sponge, and composite-ply tissues) to evaluate their ability to recover Listeria spp. A total of 240 samples for each sampling method were collected and tested. The cotton swab method of sampling was significantly (P < 0.01) less efficient in recovery of Listeria spp. than the sterile-sponge and composite-ply tissue methods, which were similar (P > 0.05) in their ability to recover Listeria spp. The specificity and sensitivity of four detection methods (conventional culture, Petrifilm Environmental Listeria Plates [ELP], lateral-flow immunoprecipitation [LFI], and automated PCR) were evaluated for identification of Listeria spp. Facilities were visited until a minimum of 100 positive and 100 negative samples per detection method were collected. The LFI and PCR methods were highly sensitive (95.5 and 99.1%, respectively) and specific (100%) relative to the culture method. The ELP method was significantly less efficient (P < 0.01) than LFI and PCR in detection of Listeria spp., with lower sensitivity (50.6%) and specificity (91.5%). Kappa values indicated excellent agreement of the LFI and PCR assays and moderate agreement of the ELP method to the culture method. Overall, ELP was easy to use but less efficient in detection of Listeria spp. from environmental samples, while the LFI and PCR methods were found to be excellent alternatives to culture, considering performance and time and labor inputs.