EFFECT OF BACTERIAL PROTEIN EXTRACTION REAGENT COMBINED WITH SODIUM AZIDE ON THE DETECTION OF ESCHERICHIA COLI O157:H7 USING IMMUNOMAGNETICELECTROCHEMELUMINESCENCE

摘要

Immunomagnetic capture combined with electrochemiluminescent detection (IM-ECL) is a rapid and sensitive method for the detection of pathogenic microorganisms from food. Prior to ECL detection enriched samples are often heated to reduce the viabilityof pathogens. In this work, a number of cell-lysis reagents and biocides were examined as alternatives to the heat treatment step to decrease bacterial viability in enriched samples as well as to improve the IM-ECL detection of Escherichia coli O157:H7.A combination of Bacterial Protein Extraction Reagent (B-PER~TM), a nonionic detergent, and sodium azide (NaN_3 decreased bacterial viability to below the level of detection (<10 cells/mL) in ground beef enrichments and resulted in a 6-fold increase in the sensitivity of IM-ECL detection of E. coli O157:H7.