TABLE 2.
Source and number of Salmonella Typhimurium DT 104 isolated in 1997 and 1998 and their MICs of enrofloxacin
| Year | Source | No. (%) of isolates | No. of NALra isolates | No. of DT 104 isolates for which the enrofloxacin MIC (μg/ml) was as follows:
|
MIC (μg/ml)b
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.015 | 0.03 | 0.06 | 0.125 | 0.25 | 0.5 | 1 | 2 | 50% | 90% | ||||
| 1997 | Total | 320 (100) | 3 | 4 | 5 | 244 | 32 | 32 | 0 | 2 | 1 | 0.06 | 0.25 |
| Pig | 167 (52.2) | 0 | 2 | 3 | 140 | 22 | 0 | 0 | 0 | 0 | 0.06 | 0.125 | |
| Cattle | 74 (23.0) | 2 | 0 | 1 | 34 | 6 | 31 | 0 | 1 | 1 | 0.125 | 0.25 | |
| Poultry | 6 (1.9) | 0 | 2 | 0 | 4 | 0 | 0 | 0 | 0 | 0 | 0.06 | 0.06 | |
| Other | 73 (22.8) | 1 | 0 | 1 | 66 | 4 | 1 | 0 | 1 | 0 | 0.06 | 0.06 | |
| 1998c | Total | 319 (100) | 8 | 0 | 2 | 266 | 42 | 1 | 1 | 7 | 0 | 0.06 | 0.125 |
| Pig | 163 (51.1) | 0 | 0 | 0 | 135 | 27 | 1 | 0 | 0 | 0 | 0.06 | 0.125 | |
| Cattle | 57 (17.9) | 5 | 0 | 2 | 47 | 3 | 0 | 0 | 5 | 0 | 0.06 | 0.125 | |
| Poultry | 20 (6.3) | 2 | 0 | 0 | 15 | 3 | 0 | 0 | 2 | 0 | 0.06 | 0.125 | |
| Other | 79 (24.8) | 1 | 0 | 0 | 69 | 9 | 0 | 1 | 0 | 0 | 0.06 | 0.125 | |
a
NALr, nalidixic acid resistant.
b
50% and 90%, MICs at which 50 and 90% of isolates, respectively, are inhibited.
c
Only strains received from January 1998 to October 1998 were investigated.