Bio-Plex suspension array immuno-detection of Listeria monocytogenes from cantaloupe and packaged salad using virulence protein inducing activated charcoal enrichment media.

摘要: Listeria monocytogenes, the causative agent of listeriosis in humans, is a Gram-positive bacterium that contracted via ingestion contaminated foods. Two largest outbreaks occurred following consumption tainted cantaloupe and packaged salads. Molecular methods immuno-based techniques for detection L. monocytogenes these food matrices can be difficult due to presence assay inhibiting elements. In this study, we utilized novel enrichment media containing activated charcoal as key ingredient induces hyperactive expression secretion virulence proteins. The Bio-Plex suspension array system, based on Luminex xMAP technology, was subsequently employed specifically detect accumulated secreted membrane bound proteins paramagnetic microsphere-antibody complexes. Cantaloupe salad samples were treated with dilution series incubated short pre-enrichment step Buffered Enrichment Broth. Secreted lysteriolysin O captured using magnetic conjugates measured Bio-Ple×200 analyzer. As few 100 CFU/g detected from both spiked samples. addition, antibody conjugated microspheres targeting protein present pathogenic nonpathogenic species used identify salad. This method presumptively identifies less than 24 h non-pathogenic within 22 h.