Table 4.
Combined 2-year data for the location and occurrence of L. monocytogenes in each of the three packinghouses (P1, P2, and P3).
| Area | Year | Samples positive for L. monocytogenes/Samples collected (%) | |||
|---|---|---|---|---|---|
| P1 | P2 | P3 | Overall | ||
| Cold storage | |||||
| Short-term and staging1 | Y1 | 10/36 (27.7) | 8/36 (22.2) | 2/36 (5.6) | 20/108 (18.5) |
| Y2 | 14/36 (38.9) | 5/36 (13.9) | 4/36 (11.1) | 23/108 (21.3) | |
| Long-term2 | Y1 | 4/30 (13.3) | 8/30 (26.7) | 1/30 (3.3) | 13/90 (14.4) |
| Y2 | 2/30 (6.7) | 6/30 (20.0) | 1/30 (3.3) | 9/90 (10.0) | |
| Sub-total | Y1 + Y2 | 30/132 (22.8) | 27/132 (20.5) | 8/132 (6.1) | 65/396 (16.4) |
| Packing line | |||||
| Dump tank | Y1 | 1/30 (3.3) | 2/29 (6.9) | 1/30 (3.3) | 4/89 (4.5) |
| Y2 | 1/30 (3.3) | 2/28 (7.1) | 0/30 (0.0) | 3/88 (3.4) | |
| Spray-wash | Y1 | 2/24 (8.3) | 7/24 (29.1) | 0/24 (0.0) | 9/72 (12.5) |
| Y2 | 7/24 (29.2) | 6/24 (25.0) | 0/24 (0.0) | 13/72 (18.0) | |
| Fan-dry | Y1 | 2/24 (8.3) | 21/24 (87.5) | 1/24 (4.2) | 24/72 (33.3) |
| Y2 | 2/24 (8.3) | 15/24 (62.5) | 1/24 (4.2) | 18/72 (25.0) | |
| Wax | Y1 | 2/30 (6.7) | 25/30 (83.3) | 6/30 (20.0) | 33/90 (36.7) |
| Y2 | 2/30 (6.7) | 22/30 (73.3) | 1/30 (3.3) | 25/90 (27.8) | |
| Potential cross-contamination sites | Y1 | 5/42 (11.9) | 21/42 (50.0) | 3/42 (7.1) | 29/126 (23.0) |
| Y2 | 5/42 (11.9) | 12/42 (28.6) | 2/42 (4.8) | 19/126 (15.0) | |
| Sub-total | Y1 + Y2 | 29/300 (9.7) | 133/297 (44.8) | 15/300 (5.0) | 177/897 (19.7) |
| Packaging line | Y1 | 0/24 (0.0) | 7/24 (29.1) | 0/24 (0.0) | 7/72 (9.7) |
| Y2 | 0/24 (0.0) | 2/24 (8.3) | 0/24 (0.0) | 2/72 (2.8) | |
| Sub-total | Y1 + Y2 | 0/48 (0.0) | 9/48 (18.8) | 0/48 (0.0) | 9/144 (6.3) |
| All samples | Y1 | 26/240 (10.8) | 99/239 (41.4) | 14/240 (5.8) | 139/719 (19.3a3) |
| Y2 | 33/240 (13.8) | 70/238 (29.4) | 9/240 (3.8) | 112/718 (15.6a) | |
| Overall | Y1 + Y2 | 59/480 (12.3B3) | 169/477 (35.4C) | 23/480 (4.8A) | 251/1437 (17.5) |
1
Staging and storage for <1 month.
2
Non-CA storage for 1–3 months.
3
Different lower or uppercase letters for each year or packinghouse, respectively, indicate significant differences (α = 0.05).