A POLYMYXIN-CLOTH ENZYME-IMMUNOASSAY SYSTEM FOR DETECTION OF ESCHERICHIA-COLI O157 IN-GROUND BEEF

A polymyxin-cloth enzyme immunoassay (polymyxin-CEIA) was developed fo r the detection of the foodborne pathogen Escherichia coli O157. This simple assay utilized inexpensive polymyxin-coated polyester cloth as an adsorbent for E. coli lipopolysaccharide (LPS) antigens present in test samples such as enrichment cultures of ground beef. Captured LPS was immunoenzymatically defected using commercially available anti-O15 7 polyclonal antibodies. The assay was sensitive and highly specific f or strains bearing the O157 and related antigens, and permitted the de tection of c. 1-10 cfus spiked into ground beef samples after a brief enrichment in double modified trypticase soy broth. We suggest that th e polymyxin-CEIA will provide a simple, rapid and inexpensive screenin g method for E. coli O157 in ground beef. (C) 1996 Academic Press Limi ted