TABLE 2.
Distribution of MICs for Enterococcus faecalis (n = 41) isolated from Australian meat chickens to 14 antimicrobialsa
| Antimicrobial | % of isolates with MIC (mg/liter) |
% non-wild type (95% CI) | Clinically resistant (%) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | 1,024 | |||
| Ampicillin | 0 | 2.4 | 14.6 | 2.4 | 61 | | 9.8 | 9.8 | 0 | 0 | 0 | 0 | 0 | 0 | 19.5 (8.8–34.9) | 9.8 |
| Chloramphenicol | 0 | 0 | 0 | 2.4 | 2.4 | 78 | 17.1 | 0 | 0 | 0 | 0 | 0 | 0 | 0.0 (0.0–8.6) | 0 |
| Daptomycin | 12.2 | 4.9 | 12.2 | 34.1 | 24.4 | | 12.2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 12.2 (4.1–26.2) | |
| Erythromycin | 48.8 | 2.4 | 17.1 | 4.9 | 0 | | 0 | 26.8 | 0 | 0 | 0 | 0 | 0 | 0 | 26.8 (14.2–42.9) | 26.8 |
| Gentamicin* | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 100 | 0 | 0 | 0 | 0 | |
| Kanamycin* | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 87.8 | 12.2 | 0 | 0 | 0 | |
| Lincomycin* | 0 | 0 | 4.9 | 0 | 0 | 4.9 | 90.2 | 0 | 0 | 0 | 0 | 0 | 0 | ||
| Linezolid | 0 | 2.4 | 0 | 65.9 | 29.3 | | 0 | 2.4 | 0 | 0 | 0 | 0 | 0 | 0 | 2.4 (0.1–12.9) | 2.4 |
| Penicillin(benzyl) | 22 | 2.4 | 12.2 | 9.8 | 34.1 | 7.3 | 2.4 | | 9.8 | 0 | 0 | 0 | 0 | 0 | 9.8 (2.7–23.1) | 12.2 |
| Quinupristin-dalfopristin* | 0 | 7.3 | 0 | 34.1 | 9.8 | 22 | 19.5 | 7.3 | 0 | 0 | 0 | 0 | 0 | ||
| Teicoplanin | 87.8 | 9.8 | 0 | 0 | | 0 | 0 | 0 | 0 | 0 | 2.4 | 0 | 0 | 0 | 2.4 (0.1–12.9) | 2.4 |
| Tetracycline | 0 | 0 | 51.2 | 0 | 2.4 | | 0 | 0 | 7.3 | 39 | 0 | 0 | 0 | 0 | 46.3 (30.7–62.6) | 46.3 |
| Vancomycin | 7.3 | 43.9 | 31.7 | 12.2 | 2.4 | | 2.4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2.4 (0.1–12.9) | 0 |
| Virginiamycin | 0 | 0 | 2.4 | 17.1 | 48.8 | 17.1 | 7.3 | 2.4 | | 0 | 4.9 | 0 | 0 | 0 | 4.9 (0.6–16.5) | |
a
Note E. faecalis is intrinsically resistant to lincomycin and quinupristin-dalfopristin. The percentages of isolates classified as non-wild type with the corresponding 95% CI and the percentages classified as clinically resistant are shown. For each drug, vertical bars show the positions of the ECOFF values, and shaded areas indicate the ranges of dilutions evaluated. ECOFF values are not presently available for antimicrobials denoted by an asterisk (*), and blank boxes in the table also indicate a lack of relevant breakpoints.