Enumeration of Escherichia coli O157:H7 from ground beef using a re-circulating immuno-magnetic bead separation

The ability of magnetic immunocapture to enumerate Escherichia coli 0157.H7 in ground beef was investigated. Ground beef was inoculated with a known quantity of a five strain mixed culture of E. coli 0157.H7, and the population subsequently enumerated by re-circulating the ground beef sample with immuno-magnetic beads. Trypsin and Polyoxyethylene Sorbitan Monolaurate (tween 20) were added to the ground beef sample and allowed to incubate for one hour to achieve a higher recovery of the target bacteria. There was statistical difference (P\u3c0.05) between the known population inoculated into the ground beef and the populations enumerated in the ground beef by the immunocapture method. The regression model showed that there is a linear relationship between the two groups. This model proves that the Pathatrix System can be used for the enumeration of E. coli 0157.H7 in ground beef