Fate of Listeria monocytogenes, Salmonella spp., and Shiga Toxin-Producing Escherichia coli on Slices of an All-Beef Soppressata during Storage

Cells of Listeria monocytogenes, Salmonella spp., or Shiga toxin-producing Escherichia coli (STEC) were inoculated (ca. 4.0 log CFU/slice) onto slices (ca. 4 g each slice) of an all-beef soppressata (ca. pH 5.05 and a(w) 0.85). The storage of vacuum-sealed slices of inoculated soppressata at 4 degrees C or 20 ffi C for 90 days resulted in reductions of all three pathogens by ca. 2.2 to 3.1 or ca. >= 3.3 log CFU/slice, respectively. When pathogen levels decreased to below detection (<= 1.18 log CFU/slice) by direct plating, it was possible to recover each of the target pathogens by enrichment, albeit more frequently from slices stored at 4 degrees C (p < 0.05) compared to 20 degrees C. In summary, the slices of the commercially produced beef soppressata selected for this study did not provide a favorable environment for either survival or outgrowth of surface-inoculated cells of L. monocytogenes, Salmonella spp., or STEC during storage.

Automated summary

Cells of Listeria monocytogenes, Salmonella spp., or Shiga toxin-producing Escherichia coli (STEC) were inoculated onto slices of all-beef soppressata. Storage of the inoculated soppressata at 4°C or 20°C for 90 days resulted in reductions of all three pathogens. Recovery of the pathogens was more frequent from slices stored at 4°C compared to 20°C.