Table 4

In vitro susceptibility of 9 strains of Streptococcus dysgalactiae 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
≤ 0.06
0.12
≤ 0.06–0.12
≥ 4
0.0
0.0
Ampicillin
≤ 0.12
0.25
≤ 0.12–0.25
≥ 8
0.0
0.0
Cephalotin
≤ 4
≤ 4
≤ 4
≥ 32
0.0
0.0
Gentamicin
8
8
4–8
≥ 16
0.0
0.0
Erythromycin
≤ 0.25
≤ 0.25
≤ 0.25
≥ 1
0.0
0.0
Oxitetracycline
8
> 64
4–> 64
≥ 8
89.0
89.0 5
Trimethoprim/Sulfamethox.
0.12
0.25
≤ 0.06–0
≥ 4
0.0
....4....

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. 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