Table 3.

MIC_Range, MIC₅₀, and MIC₉₀ values (mg/L) of Legionella pneumophila serogroup 1 (Lp1) isolates compared with serogroup 2–15 (Lp2–15).

Bacterial Strains (n° of Isolates)	Antimicrobial Agents	MIC50	MIC90	MICRange
L. pneumophila Lp1 (24)	Azithromycin	0.06	0.5	0.015–1
	Erythromycin	0.12	0.5	0.015–0.5
	Ciprofloxacin	0.015	0.03	≤0.008–0.03
	Levofloxacin	0.015	0.03	≤0.008–0.03
	Rifampicin	≤0.008	≤0.008	≤0.008
L. pneumophila Lp2–15 (34)	Azithromycin	0.015	0.03	≤0.008–8
	Erythromycin	0.06	0.12	0.015–8
	Ciprofloxacin	0.015	0.06	≤0.008–0.5
	Levofloxacin	≤0.008	0.015	≤0.008–0.5
	Rifampicin	≤0.008	≤ 0.008	≤0.008–0.015