Development and application of a flow cytometry-based method for rapid and multiplexed quantification of three foodborne pathogens in chicken breast

Chicken breast is prone to Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 contaminations. Therefore, a quantitative method for the rapid detection of these pathogens simultaneously in chicken breast is highly desirable for food safety control. This study reports a flow cytometry (FCM)-based method for rapid and multiplexed quantification of the above-stated three pathogens without enrichment. Using the developed method, the complete detection process, including a sample pretreatment procedure, the multiplex staining, and the FCM analysis, could be realized within 1 h, rendering this method more efficient than the plate counting method. The bacterial recovery rates were 96.24% for Listeria monocytogenes, 96.74% for Salmonella, and 96.42% for E. coli O157:H7. A good linear correlation was realized between the FCM-based method and the plate counting method for all three pathogens. The relative standard deviations were 3.0%, 2.7%, and 2.9% for Listeria monocytogenes, Salmonella, and E. coli O157:H7, which indicated excellent reproducibility of the method. This study is the first one to report the rapid and simultaneous quantification of foodborne pathogens in chicken breast using FCM. Moreover, the developed method was also applied successfully to the multiplexed detection of bacteria, which indicated that the method has great potential in food contamination monitoring.