The zone of growth inhibition was interpreted as sensitive, intermediate, or resis tant. The inhibition zone diameters of Ssuis strains and the reference strains were mea sured on the same day using a sliding caliper. or amoxicillin, amoxicillin-clavulanic acid, ceftiofur, erythromycin, penicillin G, and trimethoprim-sulfamethoxazole, disc diffu ion susceptibility was tested according to the