TABLE 1.

In vitro activities of 10 antimicrobial agents against 271 streptococcal strains

Organism (no. of isolates)	Antimicrobial agent	MIC (μg/ml)
		Range	MIC50	MIC90
Erythromycin-resistant S. pneumoniae (53)	Penicillin	0.03–4	1	2
	Erythromycin	1–>64	64	>64
	Roxithromycin	0.5–>64	64	>64
	Azithromycin	1–>64	64	>64
	Miocamycin	0.1–64	2	32
	Clindamycin	0.03–>64	64	>64
	Quinupristin-dalfopristin	0.2–1	0.5	1
	Linezolid	1–2	2	2
	Moxifloxacin	0.06–1	0.1	1
	Trovafloxacin	0.03–2	0.06	0.1
Erythromycin-susceptible S. pyogenes (64)	Penicillin	0.008–0.03	0.008	0.01
	Erythromycin	0.01–0.03	0.03	0.03
	Roxithromycin	0.06–0.2	0.06	0.1
	Azithromycin	0.03–0.3	0.06	0.06
	Miocamycin	0.1–0.5	0.1	0.2
	Clindamycin	0.03–0.06	0.03	0.06
	Quinupristin-dalfopristin	0.1–0.2	0.2	0.2
	Linezolid	1–2	2	2
	Moxifloxacin	0.03–0.1	0.06	0.1
	Trovafloxacin	0.03–0.1	0.06	0.1
Erythromycin-resistant S. pyogenes (53)	Penicillin	0.004–0.03	0.008	0.01
	Erythromycin	1–>64	8	16
	Roxithromycin	1–>64	16	32
	Azithromycin	2–>64	8	16
	Miocamycin	0.1–>64	0.1	0.2
	Clindamycin	0.01–>64	0.03	0.06
	Quinupristin-dalfopristin	0.1–0.5	0.2	0.2
	Linezolid	1–2	2	2
	Moxifloxacin	0.03–0.2	0.1	0.1
	Trovafloxacin	0.03–0.5	0.06	0.1
Erythromycin-susceptible S. agalactiae (53)	Penicillin	0.01–0.06	0.03	0.06
	Erythromycin	0.01–0.03	0.03	0.03
	Roxithromycin	0.06–0.1	0.1	0.1
	Azithromycin	0.03–0.3	0.03	0.03
	Miocamycin	0.2	0.2	0.2
	Clindamycin	0.03–0.06	0.03	0.06
	Quinupristin-dalfopristin	0.5–1	0.5	0.5
	Linezolid	2	2	2
	Moxifloxacin	0.06–0.1	0.06	0.1
	Trovafloxacin	0.06–0.1	0.1	0.1
Erythromycin-resistant S. agalactiae (48)	Penicillin	0.03–0.06	0.03	0.06
	Erythromycin	1–>64	8	>64
	Roxithromycin	2–>64	16	>64
	Azithromycin	1–>64	16	>64
	Miocamycin	0.2–>64	8	64
	Clindamycin	0.03–>64	4	>64
	Quinupristin-dalfopristin	0.5	0.5	0.5
	Linezolid	1–2	2	2
	Moxifloxacin	0.03–0.1	0.06	0.1
	Trovafloxacin	0.06–0.1	0.06	0.1