COMPARISON OF THE BAX FOR SCREENING ESCHERICHIA-COLI O157-H7 METHOD WITH CONVENTIONAL METHODS FOR DETECTION OF EXTREMELY LOW-LEVELS OF ESCHERICHIA-COLI O157-H7 IN-GROUND BEEF

Escherichia coli O157:H7 is an important food-borne pathogen. Often E. coli O157:H7 is difficult to detect, because it is present sporadical ly at very low levels together with very high levels of competitor org anisms which can be difficult to distinguish phenotypically. Cultural methods are time-consuming and give variable results in the detection of E. coli O157:H7. This study examined the performance of BAX for Scr eening/E. coli O157:H7, a new rapid method for the detection of E. col i O157:H7, against traditional and improved cultural methods and an im munodiffusion assay. All cultural methods demonstrated inadequacy in d etecting the presence of E. coli O157:H7 in inoculated samples. The li mitations of these cultural methods further complicate evaluation of s creening methodologies. The BAX for Screening/E. coli O157:H7 assay ou tperformed the other methods, with a detection rate of 96.5%, compared to 39% for the best cultural method and 71.5% for the immunodiffusion method. The BAX for Screening/E. coli O157:H7 assay proved to be a ra pid, highly sensitive test for the detection of low levels of E. coli O157:H7 in ground beef.