TABLE 2.
Susceptibility profiles for equine and human S. aureus isolates
| Study no. | Source of isolate | Hemolytic pattern | Susceptibility (MIC [μg/ml])a
|
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AN | AMP | FOX | CFb | CIP | XNL | CC | E | GM | K | OXc | P | TE | SXT | VA | IMP | |||
| 1 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (4.0) | R | R | R | S | S |
| 2 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 3 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 4 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 5 | Equine | Beta | S | R | R | S | S | Id | S | R | R | R | R (8.0) | R | R | R | S | S |
| 6 | Equine | Gamma | S | R | R | S | S | R | S | R | R | R | I (2.0) | R | R | R | S | S |
| 7 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (4.0) | R | R | R | S | S |
| 8 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 9 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 10 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (16.0) | R | R | R | S | S |
| 11 | Equine | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 12 | Human 1 | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 13 | Human 1 | Gamma | S | R | R | S | S | R | S | R | R | R | I (1.0) | R | R | R | S | S |
| 14 | Human 2 | Beta | S | R | R | S | S | R | S | R | R | R | R (8.0) | R | R | R | S | S |
| 15 | Human 3 | Gamma | S | R | R | S | S | R | S | R | R | R | I (1.0) | R | R | R | S | S |
AN, amikacin; AMP, ampicillin; FOX, cefoxitin; CF, cephalothin; CIP, ciprofloxacin; XNL, ceftiofur; CC, clindamycin; E, erythromycin; GM, gentamicin; K, kanamycin; OX, oxacillin; P, penicillin; TE, tetracycline; SXT, trimethoprim-sulfamethoxazole; VA, vancomycin; IMP, imipenem; S, susceptible; R, resistant.
In accordance with NCCLS guidelines, an S. aureus isolate resistant to oxacillin should also be considered resistant to all other β-lactams.
For the three gamma-hemolytic isolates, the zone size is intermediate and the MIC range is 1.0 to 2.0 μg/ml.
The zone size for this organism was 20 mm. NCCLS M31-T document-proposed guidelines indicate that resistant organisms have zone sizes of ≤17 mm.