An Innovative, Flow-Assisted, Noncompetitive Chemiluminescent Immunoassay for the Detection of Pathogenic Bacteria

Approximately 30% of these cases are caused by bacteria and their related toxic products. The bacteria species that are most frequently responsible for food contaminations are Salmonella typhimurium (meat, milk, and eggs), Escherichia coli O157:H7 (meat), Staphylococcus aureus (milk, cream, and meat), Clostridium perfringens (sausages, preserved food), Campylobacter jejuni (poultry, eggs), Vibrio parahaemolyticus (shellfish), Yersinia enterocolitica (meat, milk), and Listeria monocytogenes (dairy products). Conventional microbiological methods for the identification of pathogenic bacteria are labor-intensive (several enrichment steps) and time-consuming (2 to 3 days to obtain results). Currently, new rapid procedures based on immunological, DNA hybridization, or biosensing methods have been proposed. However, many of these rapid tests are expensive, laborious, and all of them are based on cultural enrichment to enhance sensitivity and selectivity before analysis. Simpler, faster and more sensitive diagnostic techniques are required to improve food safety (food production, processing, storage and distribution) and to screen for potential bacterial infections in humans. Several immuno-based detection methods for infectious agents have been developed recently. Such methods are of great diagnostic importance because they offer unique detection specificity and sensitivity, with relatively simple and low-cost assay formats. Most commercially available immunological methods for the detection of bacteria are based on conventional sandwich immunoassays, which involve the formation of an immunocomplex with an immobilized antibody, the target bacteria, a second labeled antibody, and the separation of free and bound antibody fractions by washing steps. Unfortunately, these separation steps reduce the assay production, so alternative approaches are welcome.