Comparison of petrifilmTM Staph Express Count System with the Bacteriological Analytical Manual direct-plating method for enumeration of Staphylococcus aureus in artificially contaminated hard cheese.

摘要

The 3M PetrifilmTM Staph Express Count System was compared with the US FDA's Bacteriological Analytical Manual (BAM) direct-plate count method for the enumeration of Staphylococcus aureus in 6 types of artificially contaminated hard cheese (Asiago, Cheddar, Gruyere, Parmesan, Romano and Swiss). 5 different samples of each cheese type were inoculated with S. aureus (ATCC 25923) to achieve low, medium and high inoculum levels. S. aureus was enumerated by the Petrifilm and BAM methods, and the results were compared. Multivariate analysis of variance revealed no significant differences (P < 0.05) between the 2 methods. The Petrifilm method compared favorably with the BAM procedure. The rapid method was more convenient to use, considerably faster and less expensive to perform than the BAM method.