Table 2. Occurrence of verotoxigenic E. coli (VTEC), L. monocytogenes, and Salmonella in irrigation water collected from seven sites in the Sumas and Serpentine watersheds.
| Site | # of Samples | Number of positive samples (% of positive samples) | |||
|---|---|---|---|---|---|
| VTEC | L. monocytogenes | Salmonella | Any Pathogen | ||
| Sumas 1a | 35 | 4 (11.4%) | 1 (2.86%) | 3 (8.57%) | 6 (17.1%) |
| Sumas 1b | 26 | 0 | 0 | 2 (7.69%) | 2 (7.69%) |
| Sumas 2 | 34 | 0 | 1 (2.94%) | 0 | 1 (2.94%) |
| Sumas 3 | 34 | 1 (2.94%) | 4 (11.8%) | 0 | 5 (14.7%) |
| Serpentine 1 | 30 | 0 | 4 (13.3%) | 1 (11.1%) | 4 (13.3%) |
| Serpentine 2 | 34 | 5 (14.7%) | 9 (26.5%) | 0 | 12 (35.3%) |
| Serpentine 3 | 30 | 1 (3.33%) | 4 (13.3%) | 0 | 5 (16.7%) |
| Total Sumas | 129 | 5 (3.88%)* | 6 (4.65%)A | 5 (3.88%)* | 14 (10.9%)A |
| Total Serpentine | 94 | 6 (6.38%)* | 17 (18.1%)B | 1 (1.06%) | 21 (22.3%)B |
| Total | 223 | 11 (4.93%) | 23 (10.3%) | 6 (2.69%) | 35 (15.7%) |
A,B Pathogens at watersheds with different letters represent a significant difference in pathogen occurrence between the two watersheds (χ2; p < 0.05).
* A significant difference in pathogen occurrence between sites within this watershed was observed (Fisher’s exact test; p < 0.10).