Supplemental Table 1: Detailed sampling instructions for environmental sample collection provided to NYSDAM inspectors trained to collect environmental and food samples for this study.
||Establishments where sliced deli meats are sampled1|
||If available and in particular if salads are sampled: Bowl, spoon, cutting boards, tables (e.g., utensils used to prepare salads) – 1 to 2 sponge samples may be taken from the most instruments that most likely harbor Listeria. If these instruments are available samples should be collected even if no salads are sampled |
||Sponge from deli case (total sample area of approx. 1 sq. yd.) – this sample should be collected from various areas in the deli case, e.g., areas close to sliced meats, areas closed to raw meats|
||Sponge from sink interior (sample whole sink)|
||Drain(s) in the store (sample whole drain, remove drain cover if possible). If available up to 3 drains should be sampled (e.g., in deli, raw meat, seafood, and produce area, if they exist). Please make sure to note location of the drain (e.g., close to deli counter, close to door form outside etc.)|
||Sponge sample form cold storage room (if available); one sample should be collected from floor (sample approx. 1 sq, yd.); 1 – 2 additional samples can be collected, e.g., from a drain in the cold room and from racks.|
||Floor in a dry isle (e.g., an isle where canned goods are sold) (sample approx. 1 sq, yd.)|
||Sponge from dairy case (sample approx. 1 sq. yd.) – if available|
||One sponge sample from floor or a foot mat near store entrance (sample approx. 1 sq. yd.)|
||Additional optional sponge samples can be taken from high risk areas for Listeria cross-contamination (e.g., areas where raw meat, vegetables, and seafood are handled)|
1Inspectors that collected deli salad samples noted whether deli salads were made in the store or whether they represented pre-made salads that were repackaged and/or aliquoted in the store;
2Addtional samples were taken from high risk areas at the inspectors’ discretion.