Table 3

In vitro susceptibility of 60 strains of Streptococcus agalactiae 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
0.12
0.12
≤ 0.06–0.12
≥ 4
0.0
0.0
Ampicillin
0.25
0.25
≤ 0.12–0.25
≥ 8
0.0
0.0
Cephalotin
≤ 4
≤ 4
≤ 4
≥ 32
0.0
0.0
Gentamicin
8
16
4–16
≥ 16
85.0
85.0
Erythromycin
≤ 0.25
≤ 0.25
≤ 0.25–1
≥ 1
3.4
3.4
Oxitetracycline
≤ 0.25
0.5
≤ 0.25–2
≥ 8
0.0
0.0 5
Trimethoprim/Sulfamethox.
0.25
0.25
≤ 0.06–2
≥ 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