Table 5.
Summary of differences in the odds of antimicrobial resistance for individual Enterococcus species isolated from calves and cows in the spring and in the fall accounting for clustering within herds using generalized estimation equations
| Fall Calf vs. Spring Calf (ref) | Spring Cow vs. Spring Calf (ref) | Fall Cow vs. Fall Calf (ref) | Fall Cow vs. Spring Cow (ref) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Species | Antimicrobial | Odds Ratio (95% CI) | P-value | Odds Ratio (95% CI) | P-value | Odds Ratio (95% CI) | P-value | Odds Ratio (95% CI) | P-value | ICC |
| E. faecalisa | Streptomycin | 0.61 (0.12-3.14) | 0.55 | 0.34 (0.02-5.66) | 0.46 | Not Estimable | > 0.99 | Not Estimable | > 0.99 | 0.61 |
| E. faecalis | Tetracycline | 0.21 (0.08-0.54) | 0.001 | 0.09 (0.02-0.43) | < 0.01 | 0.27 (0.05-1.39) | 0.12 | 0.64 (0.08-5.17) | 0.68 | 0.16 |
| E. faecalis | Tylosin | 0.74 (0.18-3.05) | 0.68 | 0.37 (0.04-3.56) | 0.39 | Not Estimable | > 0.99 | Not Estimable | > 0.99 | 0.28 |
| E. faecalis | Pan-susceptible | 4.36 (1.72-11.1) | < 0.01 | 8.15 (2.17-30.7) | < 0.01 | 2.51 (0.68-9.22) | 0.17 | 1.34 (0.27-6.72) | 0.72 | 0.28 |
| E. faecalis | > 1 Antimicrobial Class | 0.61 (0.15-2.54) | 0.50 | 0.25 (0.02-2.51) | 0.24 | Not Estimable | > 0.99 | Not Estimable | > 0.99 | 0.33 |
| E. faecalis | Multiclass resistant | 1.46 (0.17-12.2) | 0.73 | 1.18 (0.09-15.5) | 0.90 | Not Estimable | > 0.99 | Not Estimable | > 0.99 | 0.25 |
| E. faecium | Ciprofloxacin | 1.36 (0.53-3.55) | 0.52 | 0.56 (0.19-1.66) | 0.29 | 0.97 (0.09-0.35) | 0.96 | 2.60 (0.73-7.93) | 0.15 | 0.20 |
| E. faecium | Nitrofurantoin | 8.53 (2.24-32.5) | < 0.01 | 0.81 (0.16-4.19) | 0.80 | 0.31 (0.09-1.09) | 0.07 | Not Estimable | > 0.99 | 0.33 |
| E. faecium | Quinupristin/dalfopristin | 0.40 (0.09-1.84) | 0.24 | 0.23 (0.02-2.1) | 0.20 | 3.35 (0.75-15.0) | 0.11 | 5.90 (0.63-55.8) | 0.12 | 0.17 |
| E. faecium | Tetracycline | 0.30 (0.06-1.42) | 0.13 | 0.25 (0.04-1.54) | 0.14 | 2.68 (0.49-14.8) | 0.26 | 3.20 (0.39-26.6) | 0.28 | 0.32 |
| E. faecium | Tigecycline | 0.34 (0.04-2.85) | 0.32 | 0.49 (0.07-3.68) | 0.50 | 0.91 (0.1-8.61) | 0.94 | 0.64 (0.05-8.19) | 0.73 | 0.46 |
| E. faecium | Pan-susceptible | 1.53 (0.32-7.23) | 0.59 | 1.25 (0.19-8.00) | 0.81 | 1.05 (0.25-4.50) | 0.95 | 1.28 (0.22-7.53) | 0.78 | 0 |
| E. faecium | > 1 Antimicrobial Class | 0.93 (0.38-2.29) | 0.88 | 0.48 (0.17-1.33) | 0.16 | 0.70 (0.27-1.79) | 0.45 | 1.37 (0.46-4.04) | 0.57 | 0.11 |
| E. faecium | Multiclass resistant | 0.59 (0.22-1.63) | 0.31 | 0.50 (0.15-1.68) | 0.26 | 1.11 (0.37-3.35) | 0.85 | 1.32 (0.34-5.07) | 0.69 | 0.08 |
| E. hirae | Tetracycline | 5.53 (1.59-19.3) | < 0.01 | 1.02 (0.22-4.6) | 0.98 | 0.54 (0.19-1.56) | 0.26 | 2.94 (0.75-11.5) | 0.12 | 0.22 |
| E. hirae | Pan-susceptible | 1.33 (0.50-3.55) | 0.57 | 0.67 (0.20-2.21) | 0.51 | 0.64 (0.21-1.99) | 0.44 | 1.27 (0.34-4.74) | 0.73 | 0.06 |
| E. hirae | > 1 Antimicrobial Class | 0.75 (0.38-1.48) | 0.41 | 1.09 (0.54-2.22) | 0.81 | 1.31 (0.63-2.75) | 0.47 | 0.90 (0.42-1.96) | 0.79 | 0.10 |
| E. hirae | Multiclass Resistant | 0.79 (0.20-3.21) | 0.75 | 1.14 (0.28-4.67) | 0.86 | 0.99 (0.20-4.85) | 0.99 | 0.69 (0.14-3.44) | 0.65 | 0.28 |
| E. casseliflavus | Ciprofloxacin | 4.36 (1.23-15.4) | 0.02 | 0.77 (0.18-3.37) | 0.73 | 1.13 (0.57-2.24) | 0.73 | 6.39 (2.23-18.3) | 0.001 | 0.07 |
| E. casseliflavus | > 1 Antimicrobial Class | 1.71 (0.73-3.98) | 0.22 | 0.65 (0.26-1.60) | 0.35 | 1.31 (0.70-2.46) | 0.41 | 3.45 (1.62-7.34) | 0.001 | 0.17 |
| E. casseliflavus | Multiclass resistant | Not Estimable | > 0.99 | Not Estimable | > 0.99 | 3.11 (0.56-17.2) | 0.19 | 7.03 (0.74-67.1) | 0.90 | 0.14 |
ref-reference group for odds ratio generated by regression analysis.
aIntrinsic resistance [33]