TABLE 3.

Comparative in vitro activities of AC98-6446 and other antibiotics against recent streptococcal clinical isolates

Organism (no. of isolates tested)	Antibiotic	MIC (μg/ml)
		Range	50%	90%
S. pneumoniae, penicillin resistant (10)	AC98-6446	≤0.008	≤0.008	≤0.008
	Vancomycin	0.25-0.5	0.25	0.25
	Teicoplanin	≤0.008-0.03	≤0.008	0.015
	Tigecycline	0.25-0.5	0.25	0.5
	Levofloxacin	0.5-1	1	1
	Erythromycin	0.015-4	1	4
	Amoxicillin	1-4	2	4
S. pneumoniae, penicillin intermediate (10)	AC98-6446	≤0.008	≤0.008	≤0.008
	Vancomycin	0.25-0.5	0.25	0.25
	Teicoplanin	≤0.008-0.015	≤0.008	≤0.008
	Tigecycline	0.25-0.5	0.5	0.5
	Levofloxacin	1	1	1
	Erythromycin	0.015-1	0.015	0.03
	Amoxicillin	0.06-0.5	0.25	0.25
S. pneumoniae, penicillin susceptible (11)	AC98-6446	≤0.008	≤0.008	≤0.008
	Vancomycin	0.12-0.5	0.5	0.5
	Teicoplanin	≤0.008-0.03	0.015	0.03
	Tigecycline	0.25-1	0.5	0.5
	Levofloxacin	0.5-2	1	1
	Erythromycin	0.015-0.03	0.03	0.03
	Amoxicillin	≤0.008-0.03	0.015	0.015
S. pyogenes (10)	AC98-6446	≤0.008-0.06	0.015	0.03
	Vancomycin	0.25-0.5	0.25	0.25
	Teicoplanin	≤0.008-0.015	≤0.008	≤0.008
	Tigecycline	0.03-0.12	0.12	0.12
	Levofloxacin	0.12-0.5	0.25	0.5
	Erythromycin	≤0.008-0.03	0.015	0.03
	Amoxicillin	≤0.008-0.015	≤0.008	0.015
S. agalactiae (10)	AC98-6446	≤0.008-0.03	0.015	0.03
	Vancomycin	0.25-0.5	0.25	0.5
	Teicoplanin	≤0.008-0.06	0.03	0.06
	Tigecycline	0.12	0.12	0.12
	Levofloxacin	0.5-1	1	1
	Erythromycin	0.015-0.06	0.03	0.06
	Amoxicillin	≤0.008-0.06	0.03	0.06