The enumeration of coliforms and E. Coli on naturally contaminated beef: A comparison of the petrifilm(™) method with the Australian Standard.

Petrifilm(™) PEC was compared to Australian Standard (AS) methods for the enumeration of coliforms and Escherichia coli on 50 naturally contaminated beef samples from three meat works. The standard methods consist of a 3-tube most probable number test or a direct plate count on tryptone bile agar for E. coli, and violet red bile agar and the most probable number test for conliorms (AS 1766.2.12.1984 and AS 1766.2.3.1992). No significant difference was found between the methods, except that the count of E. coli on the direct plate method with a resuscitation step was significantly higher than the count on Petrifilm(™), most probable number or direct plate count without resuscitation.