TABLE 1.

Distribution of MICs for Enterococcus faecium (n = 77) isolated from Australian meat chickens to 14 antimicrobials^a

Antimicrobial	% of isolates with MIC (mg/liter)													% non-wild type (95% CI)	Clinically resistant (%)
	0.25	0.5	1	2	4	8	16	32	64	128	256	512	1,024
Ampicillin	9.1	7.8	5.2	9.1	13 |	35.1	14.3	5.2	1.3	0	0	0	0	55.8 (44.1–67.2)	20.8
Chloramphenicol*	0	0	0	0	3.9	75.3	20.8	0	0	0	0	0	0	0.0 (0.0–4.7)	0
Daptomycin	14.3	11.7	5.2	33.8	23.4 |	11.7	0	0	0	0	0	0	0	11.7 (5.5–21.0)
Erythromycin	35.1	3.9	13	9.1	0 |	3.9	35.1	0	0	0	0	0	0	39.0 (28.0–50.8)	39
Gentamicin*	0	0	0	0	0	0	0	0	0	100	0	0	0		0
Kanamycin*	0	0	0	0	0	0	0	0	0	79.2	14.3	3.9	2.6		2.6
Lincomycin*	0	0	11.7	0	0	2.6	85.7	0	0	0	0	0	0
Linezolid	0	0	0	55.8	42.9 |	0	1.3	0	0	0	0	0	0	1.3 (0.0–7.0)	1.3
Penicillin (benzyl)	27.3	11.7	7.8	7.8	31.2	3.9	5.2 |	5.2	0	0	0	0	0	5.2 (1.4–12.8)	10.4
Quinupristin-dalfopristin*	0	10.4	6.5	28.6	7.8	15.6	19.5	10.4	1.3	0	0	0	0		54.5
Teicoplanin	98.7	1.3	0	0 |	0	0	0	0	0	0	0	0	0	0.0 (0.0–4.7)	0
Tetracycline	0	0	58.4	1.3	0 |	0	0	3.9	36.4	0	0	0	0	40.3 (29.2–52.1)	40.3
Vancomycin	2.6	53.2	33.8	3.9	6.5 |	0	0	0	0	0	0	0	0	0.0 (0.0–4.7)	0
Virginiamycin	53.2	9.1	5.2	9.1	10.4 |	10.4	1.3	1.3	0	0	0	0	0	13.0 (6.4–22.6)

^aNote that E. faecium is intrinsically resistant to lincomycin. The percentages of isolates classified as non-wild type with corresponding 95% confidence interval (95% CI) and the percentages classified as clinically resistant are shown. For each drug, vertical bars show the positions of the ECOFF values, and shaded areas indicate the range of dilutions evaluated. ECOFF values are not presently available for antimicrobials denoted by an asterisk (*), and blank boxes in the table indicate a lack of relevant breakpoints.