Distribution of MICs of various antimicrobial agents for 90 S. aureus isolates obtained between 1970 and 1972 (old isolates)
| Antimicrobial agent | WTb ≤ | Number of isolates with a MIC (μg/ml) of:a | %Rd | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | >128 | 256 | 512 | 1,024 | >1,024 | |||
| Enrofloxacinc | 2 | 72 | 18 | — | — | — | — | 0 | ||||||||||||
| Erythromycin | 1 | 11 | 36 | 28 | 1 | 14 | — | — | — | — | 16.7 | |||||||||
| Gentamicin | 2 | 32 | 54 | 2 | 2 | — | — | — | — | 2.2 | ||||||||||
| Lincomycin | 2 | 9 | 37 | 22 | 5 | 3 | 1 | 1 | 2 | 10 | — | — | — | — | 18.9 | |||||
| Neomycin | 1 | 18 | 66 | 6 | — | — | — | — | 0 | |||||||||||
| Oxacillin | 2 | 4 | 47 | 35 | 4 | — | — | — | — | 0 | ||||||||||
| Penicillin | 0.12 | 31 | 1 | 3 | 52 | 3 | — | — | — | — | 64.4 | |||||||||
| Spectinomycin | 128 | 23 | 66 | 1 | — | — | — | — | 1.1 | |||||||||||
| Sulfamethoxazole | 128 | 2 | 4 | 32 | 30 | 3 | 6 | 9 | 1 | — | 3 | 3.3 | ||||||||
| Tetracycline | 1 | 26 | 17 | 3 | 15 | 29 | — | — | — | — | 48.9 | |||||||||
| Trimethoprim | 4 | 4 | 37 | 49 | — | — | — | — | 0 | |||||||||||
| Tylosinc | 64 | 15 | 27 | 27 | 9 | 1 | 11 | — | — | — | — | 13.3 | ||||||||
↵a The results in boldface type exceeded the breakpoint criteria for resistance. —, not applicable.
↵b MIC distribution for the wild-type (WT) organism according to EUCAST and categorized as WT ≤ the indicated number (μg/ml).
↵c Bimodal distribution of MICs (not available in EUCAST). The isolates with MICs in the higher ranges were considered to have acquired resistance.
↵d %R, percentage of isolates resistant to the respective antimicrobial agent.