Simultaneous Recovery of Four Heat-injured Foodborne Pathogens from a Four-compartment Thin Agar Layer Plate

We have developed and tested a 1‐step resuscitation thin agar layer (TAL) system (nonselective agar overlaid on selective agar) to effectively recover heat‐, acid‐, cold‐, and salt‐injured foodborne pathogens in liquid foods. Each TAL unit was designed for the recovery of one injured population. To improve operation efficiency we have developed a single 4‐compartment Petri dish to simultaneously recover heat‐injured Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Yersinia enterocolitica. No significant difference occurred between the single recovery unit and the 4‐compartment unit for enumeration of 4 heat‐injured pathogens (P > 0.05). This 4‐compartment TAL system is at least 4 times more efficient than the single TAL system.