Immunomagnetic detection of Bacillus stearothermophilus spores in food and environmental samples

• Published in: Applied and Environmental Microbiology Vol. 63; no. 5; pp. 1643 - 1646
• Main Authors: Blake, M.R. (Utah State University, Logan, UT.), Weimer, B.C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01-05-1997
• Subjects: ALIMENTOS; Animals; Antibodies, Bacterial - immunology; Avidin - immunology; BACILLUS STEAROTHERMOPHILUS; Bacteria; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; Biotin - immunology; Colony Count, Microbial; CONTAMINACION; CONTAMINACION BIOLOGICA; CONTAMINATION; CONTAMINATION BIOLOGIQUE; Environmental Microbiology; Enzyme-Linked Immunosorbent Assay; ESPORAS; Food contamination & poisoning; Food industries; Food Microbiology; Food science; Fundamental and applied biological sciences. Psychology; Geobacillus stearothermophilus - immunology; Immunoglobulin G - immunology; Immunomagnetic Separation - methods; LAIT; LAIT ECREME; LECHE; LECHE DESNATADA; Microbiology; Milk - microbiology; PRODUIT ALIMENTAIRE; Sensitivity and Specificity; Soil Microbiology; SPORE; Spores, Bacterial - immunology; Spores, Bacterial - isolation & purification; Tests; Immunomagnetic method; Fluorescence; Foodstuff; Method; Bacillaceae; Spores; Bacillales; Bacillus stearothermophilus; Bacteria; Environment; Detection; Biological contamination; ELISA assay
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.63.5.1643-1646.1997

There are currently no methods for the rapid and sensitive detection of bacterial spores that could be used to direct raw materials containing high spore loads away from products that pose a food safety risk. Existing methods require an overnight incubation, cannot detect spores below 10(5) CFU/ml, or are not specific to particular species. This work describes a method to specifically detect 10(4) CFU of bacterial spores per ml within 2 h. Polyclonal antibodies to Bacillus stearothermophilus spores were attached to 2.8-micrometer-diameter magnetic polystyrene beads by using a polythreonine cross-linker via the antibody carbohydrate moiety. A biotin-avidin-amplified sandwich enzyme-linked immunosorbent assay coupled to a fluorescent substrate was used to quantitate captured spores. The concentration of B. stearothermophilus spores in samples was linearly correlated to fluorescent activity (r2