Rapid Detection of Microbial Mass Spectra VITEK-MS for Campylobacter jejuni and Listeria monocytogenes

Abstract

A matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) method were established to detect Campylobacter jejuni and Listeria monocytogenes from a chicken farm and samples from commercial live chickens. Suspected isolates were pretreated and crystallized by matrix solutions consisting of ethanol, acetonitrile, and water with different proportions. The effect of matrix composition was evaluated by examining the differences in characteristic peak values and relative abundances. Significantly different matrix solutions were needed for the detection of C. jejuni and L. monocytogenes: the former did not require lysis by formic acid and was sensitive to trifluoroacetic acid (TFA), but the latter was just the opposite. Control of the water content in matrix solution, TFA concentration, and matrix concentration will enhance the number and relative abundance of characteristic peaks and improve the detection rate. An optimized pretreatment enables the rapid identification of foodborne pathogens, which will make it possible to improve the timeliness of disease prevention and foodborne risk monitoring.