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. 2004 Oct;70(10):6005–6011. doi: 10.1128/AEM.70.10.6005-6011.2004

TABLE 3.

MIC distributions of selected antimicrobials for E. faecalis and E. faecium isolates from the poultry production environment

Class Antimicrobial agenta Range (μg/ml) Species No. of isolates for which the MIC (μg/ml) wasb:
% resistant
≤0.25 0.5 1 2 4 8 16 32 64 128 256 ≥256
Bambermycin BMB 0.5-32 E. faecalis 1 43 121 10 1 NAc
E. faecium 2 8 94 NA
Chloramphenicol CHL 2-64 E. faecalis 170 6 0
E. faecium 18 84 2 0
Fluoroquinolone CIP 0.06-4 E. faecalis 1 23 106 43 3 2
E. faecium 1 4 45 53 1 52
Lincosamide CLI 0.5-2 E. faecalis 176 100
E. faecium 2 8 6 1 87 85
LIN 1-32 E. faecalis 22 154 NA
E. faecium 1 2 2 4 2 93 NA
Macrolide ERY 0.12-32 E. faecalis 11 2 31 10 1 5 2 2 112 69
E. faecium 44 3 15 3 4 16 1 18 34
TYL 1-32 E. faecalis 6 46 3 1 1 119 NA
E. faecium 3 29 52 6 14 NA
Penicillin AMP 0.25-16 E. faecalis 1 5 125 45 0
E. faecium 4 2 2 14 29 52 1 1
PEN 0.25-128 E. faecalis 2 121 53 0
E. faecium 3 2 2 11 12 28 45 1 71
Peptide BAC 8-256d E. faecalis 1 2 9 3 1 160 NA
E. faecium 1 7 96 NA
Streptogramin Q-D 0.5-32 E. faecalis 7 17 145 7 96
E. faecium 2 13 23 13 20 21 12 63
VIR 0.5-32 E. faecalis 7 35 114 20 NA
E. faecium 4 22 11 5 11 22 22 7 NA
Tetracycline TET 0.25-32 E. faecalis 6 9 1 1 16 143 91
E. faecium 3 17 1 1 1 7 74 79
a

BMB, bambermycin; CHL, chloramphenicol; CIP, ciprofloxacin; CLI, clindamycin; LIN, lincomycin; ERY, erythromycin; TYL, tylosin; AMP, ampicillin; PEN, penicillin; BAC, bacitracin; Q-D, quinupristin-dalfopristin; VIR, virginiamycin; TET, tetracycline. Resistance breakpoints for Enterococcus spp. (in μg/ml) were >16 for chloramphenicol, ≥4 for ciprofloxacin, >2 for clindamycin, >4 for erythromycin, >8 for ampicillin and penicillin, ≥4 for quinupristin-dalfopristin, and >8 for tetracycline. The vertical lines indicate breakpoints for the antimicrobials.

b

MICs which exceeded either the upper or lower limit of the tested range were listed in the next dilution series.

c

NA, not applicable (no established NCCLS breakpoint).

d

Expressed in international units (IU) per milliliter.