TABLE 1.

MICs of six antimicrobial agents for Swedish field isolates of Brachyspira spp.

Groupa	No. of isolates	Yr of collection	MIC (μg/ml) of:
			Tiamulin			Tylosin			Erythromycin			Clindamycin			Virginiamycin			Carbadox
			50%	90%	Range	50%	90%	Range	50%	90%	Range	50%	90%	Range	50%	90%	Range	50%	90%	Range
I	15	1990-1993	0.03	0.25	≤0.016-0.25	8	>256	≤2->256	16	>256	≤2->256	0.06	>4	≤0.03->4	2	4	0.5-4	0.016	0.06	≤0.004-0.125
I	57	1996-1999	0.125	0.125	0.03-0.25	>256	>256	4->256	>256	>256	≤2->256	4	>4	≤0.03->4	2	4	1-16	0.03	0.06	≤0.004-0.125
II	20	1990-1999	0.06	0.25	≤0.016-2	4	>256	≤2->256	8	>256	≤2->256	0.06	4	≤0.03->4	1	2	0.5-4	0.008	0.03	0.008-0.06
III	16	1990-1998	0.06	2	0.03->2	8	16	≤2->256	32	64	≤2->256	0.125	4	≤0.03->4	2	8	0.5-16	0.016	0.03	0.008-0.06

^aSee the text.