P2-177 A Single Laboratory Validation for the Microbial Identification of Salmonella spp., Escherichia coli, and Listeria monocytogenes Utilizing MALDI-TOF Technology

Tuesday, July 11, 2017
Exhibit Hall (Tampa Convention Center)
Michael Brown , U.S. Food and Drug Administration , Bothell , WA
Kristopher Stanya , U.S. Food and Drug Administration , Bothell , WA
Nichelle Kunecke , U.S. Food and Drug Administration , Bothell , WA
Lauren May , U.S. Food and Drug Administration , Bothell , WA
Ken Yoshitomi , U.S. Food and Drug Administration , Rockville , MD
Lisa Newberry , U.S. Food and Drug Administration , Bothell , WA
Introduction: Recent advances in mass spectrometry have resulted in a new generation of stand-alone systems for bacterial identification using MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time-of-flight Mass Spectrometry) technology.

Purpose: This study evaluated the performance of the VITEK® MS microbial identification system with regard to rapid identification of food associated bacterial isolates. These instruments have the capability to significantly reduce identification timeframes for unknown bacterial isolates from hours to minutes when compared to the current, validated identification systems (VITEK® 2, API®).

Methods: A randomized, blinded bacterial panel consisting of 232 traceable, previously characterized environmental and reference isolates consisting of Salmonella spp. (n=102), Escherichia coli (n=50), Listeria monocytogenes (n=50), and various exclusionary organisms (n=30) were analyzed in parallel using both the VITEK® MS and the VITEK®2 systems.

Results: The results of this study indicate that the VITEK® MS produced equivalent identification of the three major bacterial species, 96%, 98% and 99% agreement for L. monocytogenes, E. coli and Salmonella spp., respectively, when compared to the VITEK® 2 reference method. Additionally, the VITEK®MS system did not identify any of the exclusionary organism panel as one of the three target pathogens or as any other species.

Significance: Single laboratory validation results support further evaluation in a multi-laboratory study, with the goal of routine implementation of the VITEK® MS for rapid pathogen identification from food samples.