Table 1.
Cumulative resistance profiles and MICs for S. aureus isolates
| Antibiotic | S. aureus | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All | MRSA | MSSA | ||||||||||
| N | %S | %R | MIC90 | N | %S | %R | MIC90 | N | %S | %R | MIC90 | |
| Vancomycin | 1,695 | 100 | 0 | 1 | 621 | 100 | 0 | 1 | 1,074 | 100 | 0 | 1 |
| Besifloxacin | 1,695 | NAb | NAb | 1 | 621 | NAb | NAb | 2 | 1,074 | NAb | NAb | 0.25 |
| Moxifloxacin | 1,695 | 66.4 | 33.6 | 4 | 621 | 27.2 | 72.8 | 16 | 1,074 | 89.0 | 11 | 1 |
| Gatifloxacin | 1,495 | 65.9 | 34.1 | 8 | 543 | 26.7 | 73.3 | 16 | 952 | 88.2 | 11.8 | 1 |
| Ciprofloxacin | 1,695 | 64.3 | 35.8 | 128 | 621 | 24.5 | 75.5 | 256 | 1,074 | 87.2 | 12.8 | 8 |
| Levofloxacin | 1,495 | 65.7 | 34.3 | 32 | 543 | 26.2 | 73.9 | 128 | 952 | 88.2 | 11.8 | 4 |
| Ofloxacin | 1,495 | 65.2 | 34.9 | >8 | 543 | 25.8 | 74.2 | >8 | 952 | 87.6 | 12.4 | 8 |
| Azithromycin | 1,695 | 39.4 | 60.6 | >512 | 621 | 7.2 | 92.8 | >512 | 1,074 | 58.0 | 42.0 | >512 |
| Chloramphenicol | 1,495 | 93.9 | 6.1 | 8 | 543 | 89.5 | 10.5 | 16 | 952 | 96.4 | 3.6 | 8 |
| Clindamycin | 1,695 | 84.6 | 15.4 | >2 | 621 | 69.7 | 30.3 | >2 | 1,074 | 93.2 | 6.8 | 0.25 |
| Methicillina | 1,695 | 63.4 | 36.6 | >2 | 621 | 0 | 100 | >4 | 1,074 | 100 | 0 | 0.5 |
| Tetracycline | 419 | 95.7 | 4.3 | 0.5 | 103 | 90.3 | 9.7 | 4 | 316 | 97.5 | 2.5 | 0.5 |
| Tobramycin | 1,695 | 82.6 | 17.4 | 128 | 621 | 58.9 | 41.1 | 256 | 1,074 | 96.3 | 3.7 | 0.5 |
| Trimethoprim | 1,495 | 95.7 | 4.4 | 4 | 543 | 94.1 | 5.9 | 2 | 952 | 96.5 | 3.5 | 4 |
Notes:
a
Oxacillin was used as a surrogate for methicillin.
b
Clinical and Laboratory Standards Institute interpretive breakpoints are not available.
Abbreviations: MIC90, minimum inhibitory concentration that inhibits the growth of 90% of indicated isolates (µg/mL); MRSA, methicillin-resistant S. aureus; MSSA, methicillin-susceptible S. aureus; NA, not applicable; %R, percentage of resistant isolates; %S, percentage of susceptible isolates.