Review Book

and the US Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 5 Salmonella (7) reference methods. The method comparison studies were conducted using the current versions of the reference methods available at the time of validation. PTM studies included product consistency and stability studies, robustness studies, inclusivity and exclusivity studies and an independent laboratory evaluation. The purpose of this collaborative study was to meet the requirements for submission as an AOAC Official Methods of Analysis SM based on current AOAC guidelines. The study compared the reproducibility of the candidate method for one matrix, raw ground beef (80% lean), using a composite test portion, to the USDA FSIS MLG 4.10 reference method.

Collaborative Study

Study Design

One matrix, raw ground beef (80% lean), was evaluated in the study. The matrix was obtained from a local butcher and screened for the presence of Salmonella by the GENE-UP SLM and MLG 4.10 reference methods. The matrix was artificially contaminated with S. Typhimurium National Collection of Type Cultures (NCTC; Salisbury, UK) 12023 (Bovine, septicemic liver) at two levels of contamination: a high inoculation level of ~2 CFU/test portion and a low inoculation level of ~0.7 CFU/test portion. A set of non-inoculated control test portions (0 CFU/test portion) were also included. Twelve replicate samples from each of the three inoculation levels were analyzed by each participant. A total of 72 unpaired samples, 36 for the candidate method and 36 for the MLG 4.10 reference method, was sent to each participant. Collaborators were also sent a test portion

4