Table 1. Tested antimicrobial agents and their ranges.

Antimicrobial agent	Ranges (μg/ml)
ampicillin	0.03–64
amoxicillin/clavulanic acid 2:1 ratio	0.03/0.015–64/32
ceftiofur	0.03–64
cefquinome	0.015–32
cefoperazone	0.06–32
cefotaxime	0.015–32
chloramphenicol	0.5–64
ciprofloxacin 1	0.008–16
colistin	0.03–16
doxycycline	0.06–128
enrofloxacin	0.008–16
florfenicol	0.12–256
gentamicin	0.12–256
imipenem	0.015–32
marbofloxacin 1	0.008–16
nalidixic acid	0.06–128
neomycin 1	0.03–128
penicillin	0.015–32
spiramycin	0.06–128
streptomycin 1	0.25–256
tiamulin	0.03–64
tetracycline	0.12–128
tilmicosin	0.06–64
trimethoprim/sulfamethoxazole (1:19 ratio)	0.015/0.3–32/608

¹ these antimicrobial agents were included only in the interlaboratory comparison.