Laboratory evaluation of a commercial microbial control system.

A new product, the 3M Brand Microbial Control System for monitoring the reproducibility of Bauer-Kirby susceptibility tests, was compared with standard ATCC strains of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Results are presented from four independent laboratories in which all obvious protocol variables, excluding media and personnel, were identical. Evaluation of the system revealed that the commercial procedure was simple to implement and efficacious and produced results equivalent to those derived from ATCC control strains of E. coli, S. aureus, and P. aeruginosa.