Evaluation of a Chromogenic Medium for Identification and Differentiation of Listeria monocytogenes in Selected Foods
| Autor: | Jean-Pierre Facon, Asmita Patel, Wendy F Lauer |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
food.ingredient
Xylose medicine.disease_cause Analytical Chemistry Microbiology chemistry.chemical_compound food Listeria monocytogenes medicine Environmental Chemistry Agar Coloring Agents Pharmacology biology Chromogenic business.industry Phosphatidylinositol Diacylglycerol-Lyase Reproducibility of Results Reference Standards Food safety biology.organism_classification Culture Media chemistry Food Microbiology Listeria business Agronomy and Crop Science Bacteria Food Science Phosphatidylinositol phospholipase C activity |
| Zdroj: | Journal of AOAC INTERNATIONAL. 88:511-517 |
| ISSN: | 1944-7922 1060-3271 |
| DOI: | 10.1093/jaoac/88.2.511 |
| Popis: | Listeria monocytogenes continues to be a threat to food safety in the United States despite a “zero tolerance” policy. When Listeria species are identified by standard cultural methods, confirmation of L. monocytogenes takes days to complete. RAPID'L.Mono™ agar, developed by Bio-Rad Laboratories, is a chromogenic medium that differentiates L. monocytogenes from other species of Listeria by a simple color change reaction. Differentiation is based on the specific detection of phosphatidylinositol phospholipase C activity, resulting in a blue colony, and the inability of L. monocytogenes to metabolize xylose, resulting in the absence of a yellow halo. Detection principles of standard method agars, Oxford and PALCAM, are based on the ability of all species of Listeria to hydrolyze esculin. Thus, all species of Listeria have similar colony morphology on these agars, making differentiation of pathogenic L. monocytogenes from other nonhuman pathogens difficult. RAPID'L.Mono agar has been validated with surimi, mixed salad, brie, and processed deli turkey because of the prevalence of L. monocytogenes in these foods. Sensitivity and specificity for this medium was determined to be 99.4 and 100%, respectively. Overall method agreement of RAPID'L.Mono with standard culture methods (U.S. Department of Agriculture/Food Safety and Inspection Service; U.S. Food and Drug Administration/Bacteriological Analytical Manual; and AOAC INTERNATIONAL) was excellent, with enrichment protocols 24 h shorter than those of standard methods. |
| Databáze: | OpenAIRE |
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