ARS | Publication request: Rapid identification of Listeria spp.: an AOAC performance test of the MIT 1000 rapid microbial identification system

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 22, 2009
Publication Date: N/A

Technical Abstract: Methods that rapidly confirm the identification of foodborne pathogens are highly desired. The Micro Imaging Technology (MIT) 1000 Rapid Microbial Identification (RMID) System is a benchtop instrument that detects laser light scattered from individual bacterial cells in solution with an array of 35 individually addressed photodiode detectors. Identification is based on pattern recognition by an automated algorithm-based comparison of averaged scattered light signals and scatter pattern libraries. Identification times are less than 10 min and operating costs are extremely low. The MIT RMID was evaluated for identification of Listeria spp. Listeria are common environmental microorganisms and one species, L. monocytogenes, is a leading cause of death among foodborne pathogenic bacteria. Under an AOAC RI Evaluation Test Protocol, a total of 55 microbial isolates were tested of which 25 were Listeria spp. and 30 were a variety of other bacterial species. The system identified each of the strains of Listeria and each strain of other bacterial species was properly reported as unknown (overall accuracy of 99%). Although some sensitivity to deviations in the sample preparation protocol was observed, the MIT RMID performed well in tests over several ruggedness parameters. As a result of these studies the MIT RMID was granted The AOAC Research Institute Performance Tested Method status.