TABLE 1.

Comparison of in vitro activities of 13 antimicrobial agents against Legionella spp., determined at 48 h of incubation

Antibiotic	No. of strains tested with inoculum of 104a	MIC (μg/ml) at inoculum size shown (CFU/spot)
		Range		MIC50		MIC90
		104	105	104	105	104	105
HMR 3647	27	≤0.004–0.06	≤0.004–0.12	0.008	0.015	0.03	0.03
Erythromycin A	27	0.008–0.25	0.06–0.5	0.03	0.12	0.12	0.12
Clarithromycin	27	≤0.004	≤0.004–0.03	≤0.004	≤0.004	≤0.004	≤0.004
Roxithromycin	27	≤0.004–0.06	0.03–0.25	0.015	0.06	0.03	0.12
Levofloxacin	27	≤0.004–0.03	0.015–0.06	0.008	0.015	0.015	0.03
BAY 12-8039	27	0.015–0.06	0.03–0.12	0.03	0.03	0.06	0.06
Rifampin	27	≤0.0005–0.015	≤0.0005–0.015	≤0.0005	≤0.0005	0.002	0.008
Rifapentine	27	≤0.001–0.002	≤0.001–0.002	≤0.001	≤0.001	≤0.001	0.002
Dalfopristin-quinupristin	24	0.015–0.05	0.12–1	0.12	0.25	0.5	0.5
Doxycycline	24	0.5–2	1.0–8.0	1	4	2	8
Eperezolid	24	1.0–8	2–≥16	1	4	4	≥16
Linezolid	24	1.0–4	4.0–8	2	4	4	8
Clindamycin	27	0.008–8	1.0–16	2	8	8	8

^an = 30 strains for the larger inoculum in all cases.