Table 5.
Crude prevalence of resistance of M. haemolytica isolates (n = 2,989).a
| Resistance Phenotype | No. of Isolates | % (95% CI)e |
|---|---|---|
| Pan‐susceptible | 2,623 | 87.8 (87.0–89.4) |
| Amikacinb | 3 | 0.1 (0.0–0.3) |
| Amoxicillin‐clavulanatec | 34 | 0.7 (0.5–1.0) |
| Ampicillinc | 70 | 1.5 (1.2–1.9) |
| Cefoxitinb | 5 | 0.2 (0.1–0.4) |
| Ceftiofurc | 2 | 0.0 (0.0–0.2) |
| Ceftriaxoneb | 1 | 0.0 (0.0–0.2) |
| Chloramphenicolb | 0 | 0.0 (0.0–0.1) |
| Ciprofloxacinb | 0 | 0.0 (0.0–0.2) |
| Enrofloxacind | 1 | 0.0 (0.0–0.3) |
| Florfenicold | 2 | 0.1 (0.0–0.4) |
| Gentamicinc | 0 | 0.0 (0.0–0.1) |
| Kanamycinb | 108 | 3.8 (3.2–4.6) |
| Nalidix acidb | 4 | 0.1 (0.0–0.3) |
| Streptomycinb | 119 | 4.2 (3.5–5.0) |
| Sulfonamideb | 12 | 0.4 (0.2–0.8) |
| Spectinomycind | 81 | 4.5 (3.7–5.6) |
| Danofloxacind | 35 | 2.0 (1.4–2.7) |
| Tilmicosind | 5 | 0.3 (0.1–0.7) |
| Tulathromycind | 2 | 0.1 (0.0–0.4) |
| Tetracyclinec | 204 | 4.4 (3.9–5.1) |
| Trimethoprim‐sulfadiazinec | 9 | 0.2 (0.1–0.4) |
a
Isolates can be listed more than once if they were multiply resistant; 1,574 isolates were tested by both broth microdilution and disk diffusion, 1,200 isolates were tested by only broth microdilution, and 215 isolates tested only by disk diffusion, for a total of 2,833 test results from broth microdilution and 1,789 from disk diffusion (4,622 total test results).
b
Tested by broth microdilution only.
c
Tested by both broth microdilution and disk diffusion.
d
Tested by disk diffusion only.
e
Adjusted CI for binomial proportions (adding 2 successes and 2 failures) were estimated as previously described.11