Table 2

In vitro susceptibility of 41 strains of Coagulase Negative Staphylococcus obtained from clinical and sub-clinical bovine mastitis cases from the West Littoral Region of Uruguay.


MIC1(μg/ml)
% Resistance



Antimicrobial Agent
MIC502
MIC903
Range
Breakpoint
VETMIC
Agar disk diffusion test

Penicillin
0.5
> 4
0.12–> 8
≥ 0.25
27.0
22.0 5
Ampicillin
0.5
2
≤ 0.12–> 16
≤ 0.5
24.4
22.0 5
Oxacillin
≤ 0.5
≤ 0.5
≤ 0.5–1
≥ 4
0.0
0.0
Cephalotin
≤ 4
≤ 4
≤ 4
≤ 32
0.0
0.0
Gentamicin
≤ 1
≤ 1
≤ 1–4
≥ 16
0.0
0.0
Erythromycin
≤ 0.5
≤ 0.5
≤ 0.5
≥ 8
0.0
0.0
Oxitetracycline
2
> 64
≤ 0.25–> 64
≥ 16
13.9
13.9 6
Enrofloxacin
≤ 0.25
≤ 0.25
≤ 0.25–0.5
≥ 2
0.0
0.0
Neomycin
≤ 1
≤ 1
≤ 1–64
≥ 64
2.0
2.0
Clindamycin
≤ 1
≤ 1
≤ 1
≥ 4
0.0
....4....
Amoxicillin/Clavulanic acid
....4....
....4....
....4....
....4....
....4....
0.0
Trimethoprim/Sulfamethox.
0.25
0.5
< 0.06–8
≥ 4
7.3
0.0 5

1 Minimum inhibitory concentration. 2 Lowest concentration inhibiting 50% of the isolated tested.

3 Lowest concentration inhibiting 90% of the isolated tested. 4 Test not performed.

5. No significant differences between methods. 7 Tetracycline disk were used to perform agar disks diffusion.

Gianneechini et al. Acta Veterinaria Scandinavica 2002 43:31   doi:10.1186/1751-0147-43-31