TABLE 4.
Distribution of MIC for methicillin-resistant coagulase-positive staphylococci in each SCCmec typea
| Antimicrobial agent | Breakpoint (mg/liter) | MRSA (n = 33) |
MRSP (n = 27) |
MRSS (n = 5) |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of resistant isolates (%) | Range of MICs for the following SCCmec typeb: |
No. of resistant isolates (%) | Range of MICs for the following SCCmec type: |
No. of resistant isolates (%) | Range of MICs for SCCmec type IV (n = 5) | |||||||||
| I (n = 3) | II (n = 16) | II − pUB110 (n = 6) | II − kdp (n = 1) | IV + pUB110 (n = 5) | IV + pUB110 + pls (n = 2) | II-III (n = 23) | V (n = 3) | UT (n = 1) | ||||||
| Oxacillin | ≧4 | 33 (100) | >128 | ≧128 | ≧128 | 128 | ≧128 | ≧128 | 27 (100) | ≧128 | 16-≧128 | >128 | 5 (100) | >128 |
| Ampicillin | ≧0.25 | 33 (100) | 32-64 | 32-64 | 32-64 | 32 | 16-64 | 32-64 | 27 (100) | 0.5-64 | 16 | 32 | 5 (100) | 8-16 |
| Cefazolin | ≧32 | 33 (100) | 256 | ≧256 | 256 | 64 | 128-256 | 64-128 | 13 (48.1) | 0.25-256 | 0.5-2 | 32 | 5 (100) | 128-256 |
| Imipenem | ≧16 | 27 (81.8) | 16 | ≧16 | ≧16 | 1 | 0.5->16 | 2-16 | 0 | ≦0.5 | ≦0.5 | ≦0.5 | 0 | ≦0.5 |
| Kanamycin | ≧32 | 27 (81.8) | >512 | 64->512 | 2-16 | 64 | 256 | >512 | 27 (100) | 256->512 | 256 | >512 | 0 | 1 |
| Gentamicin | ≧8 | 22 (66.7) | 64-128 | 0.5-128 | ≦0.25-2 | ≦0.25 | 32-256 | 32->512 | 26 (96.3) | 8-64 | 4-16 | 16 | 0 | ≦0.25 |
| Arbekacin | ≥16 | 0 | ≦0.5-1 | ≦0.5-1 | ≦0.5 | ≦0.5 | ≦0.5-1 | ≦0.5-4 | 0 | ≦0.5-2 | ≦0.5 | ≦0.5 | 0 | ≦0.5 |
| Erythromycin | ≧8 | 32 (97.0) | >128 | 8->128 | >128 | >128 | >128 | >128 | 27 (100) | >128 | >128 | >128 | 0 | ≦0.125 |
| Chloramphenicol | ≧32 | 8 (24.2) | 8 | 8-64 | 8 | 8 | 1 | 8-128 | 21 (77.8) | 1-256 | 1-64 | 64 | 3 (60) | 4-64 |
| Minocycline | ≧16 | 8 (24.2) | 8 | 4-16 | 4->16 | ≦0.5 | ≦0.5 | ≦0.5 | 0 | ≦0.5-2 | 2 | ≦0.5 | 0 | ≦0.5 |
| Tetracyclinec or oxytetracyclined | ≧32 | 25 (75.8) | 64 | 32-64 | 32-128 | 4 | 1 | 0.25 | 17 (63.0) | 1->64 | 1-64 | ≦0.125 | 0 | 1 |
| Vancomycin | >4 | 0 | 0.5 | 0.5-2 | 1-2 | 1 | 1-2 | 0.5-1 | 0 | 0.25-2 | 1 | 0.25 | 0 | 1 |
| Teicoplanin | >8 | 0 | 0.5-1 | 0.5-4 | 1-2 | 2 | 0.5-2 | 0.5-1 | 0 | 0.5-2 | 0.5-4 | 0.5 | 0 | 0.5-1 |
| Ciprofloxacinc | ≧4 | 14 (100) | ≧128 | 16->128 | 16-64 | 16 | 11 (40.7) | 8-32 | ≦0.125 | 32 | 5 (100) | 16-32 | ||
| Enrofloxacin | ≧4 | 18 (94.7) | ≧128 | 32 | 1 | 8 | 14 (87.5) | 32-64 | <0.125-0.5 | |||||
a
MRSA, methicillin-resistant S. aureus; MRSP, methicillin-resistant S. pseudintermedius; MRSS, methicillin-resistant S. schleiferi; UT, untypeable.
b
Range of MICs for SCCmec types I, II, and IV with (+) and without (−) pUB110 and the kdp or pls gene. The number of isolates is shown in the parentheses after the SCCmec type.
c
Tetracycline and ciprofloxacin were used to test isolates obtained in 2008.
d
Oxytetracycline and enrofloxacin were used to test isolates obtained in 2007.