Purpose: As part of the AOAC® Research Institute validation process, the alternative method was compared to the FDA Bacteriological Analytical Manual (BAM) for the food and environmental samples during the internal and independent laboratory method comparison studies.
Methods: Twelve naturally and artificially contaminated matrices were tested including meat, poultry, dairy, seafood, oatmeal, rice and stainless steel surface. Five replicates of three lots for each food and environmental matrix were tested for a total of 180 samples. Inoculated cards were incubated for 22 - 27 h at 30 ± 1°C and then read using the automated reader. Standard method testing was performed as detailed in the FDA-BAM.
Results: The enumeration values obtained from both methods were converted into log and an overall bias was determined. The overall calculated bias was -0.043 with a 95% confidence (-0.119; 0.034) interval that contains zero, indicating that there was no significant difference between the TEMPO BC and the reference method.
Significance: The alternate method provides an automated method for the enumeration of Bacillus cereus group species in food and environmental samples with next day results. The automated method eliminates the subjectivity and potential for plate count variability along with additional advantages of increased efficiency, better traceability and significant labor savings.