TABLE 3.

The effect of levofloxacin, rifampin, and erythromycin at maximum attainable serum drug concentrations against intracellular L. pneumophila L-1033 (pH 7.4)

Antibiotic	Antibiotic concn (μg/ml)	Antibiotic removeda	Bacterial killing (log10 CFU/ml)b on assay day:
			1	2	3	4
Control			0.64	0.39	0.12	−0.32
Levofloxacin	5	No	−2.48	−2.96	−3.49	−4.22
	5	Yes		−1.44	−1.55	−1.35
Rifampin	8	No	−0.10	−1.45	−3.67	−4.43
	8	Yes		−0.32	−0.91	−1.15
Erythromycin	10	No	−0.04	0.07	0.02	−0.02
	10	Yes		0.12	−0.02	−0.33

^aAntibiotics were removed from the assay on day 1, and the results were compared with controls (antibiotic not removed). 

^bSee Table 1, footnote a. SEM range for controls is 0.16 to 0.18, and that for antibiotic-containing assays is 0.46 to 0.65.