TABLE 3.
Frequencies of antimicrobial resistance in E. coli isolates from pigs on five Ontario farms and from wild small mammals in the vicinity of these farms and in five geographically matched natural areas
| Antimicrobial agenta | No. (%) of resistant isolates from swine (n = 125)b | Wild small mammals
|
|||||
|---|---|---|---|---|---|---|---|
| Farms
|
Natural areas
|
Total
|
|||||
| No. (%) of resistant isolates (n = 42) | No. (%) of animals with resistant isolates (n = 22) | No. (%) of resistant isolates (n = 37) | No. (%) of animals with resistant isolates (n = 20) | No. (%) of resistant isolates (n = 79) | No. (%) of animals with resistant isolates (n = 42) | ||
| Ampicillin | 28 (22) | 1 (2) | 1 (5) | 3 (8) | 2 (15) | 4 (5) | 3 (7) |
| Amoxicillin/clavulanic acid | 5 (4) | 0 | 0 | 0 | |||
| Cefoxitin | 3 (2) | 1 (2) | 1 (5) | 0 | 1 (1) | 1 (2) | |
| Ceftiofur | 3 (2) | 0 | 0 | 0 | |||
| Ceftriaxone | 3 (2) | 0 | 0 | 0 | |||
| Streptomycin | 48 (38) | 3 (7) | 2 (9) | 0 | 3 (4) | 2 (7) | |
| Kanamycin | 11 (9) | 0 | 0 | 0 | |||
| Sulfizoxazole | 62 (50) | 5 (12) | 3 (14) | 0 | 5 (6) | 3 (12) | |
| Trimethoprim/sulfamethoxazole | 8 (6) | 1 (2) | 1 (9) | 0 | 1 (1) | 1 (2) | |
| Tetracycline | 104 (83) | 10 (24) | 6 (27) | 2 (5) | 1 (5) | 12 (15) | 7 (29) |
| Chloramphenicol | 13 (10) | 2 (5) | 1 (5) | 0 | 2 (3) | 1 (2) | |
a
No resistance to amikacin, ciprofloxacin, gentamicin, and nalidixic acid was detected in E. coli isolates from either wild small mammals or swine.
b
Twenty-five isolates from pooled fecal samples per farm were examined for five farms.