TABLE 3.

Activities of besifloxacin and comparators against gram-positive and -negative anaerobic bacteria

Species (no. of isolates) and test drug	MIC (μg/ml)
	Range	50%	90%	%Sa
Bacteroides fragilis (n = 20)
Besifloxacin	0.25-2	0.5	1	NA
Moxifloxacin	0.25-8	0.5	2	95.0
Gatifloxacin	1-16	2	4	NA
Clindamycin	0.5->8	2	>8	65.0
Metronidazole	2-2	2	2	100
Clostridium perfringens (n = 21)
Besifloxacin	0.12-0.25	0.25	0.25	NA
Moxifloxacin	0.25-0.5	0.5	0.5	100.0
Gatifloxacin	0.5-1	1	1	NA
Clindamycin	0.06-4	2	4	85.7
Metronidazole	1-4	2	4	100.0
Fusobacterium spp. (n = 21)
Besifloxacin	0.12-8	0.25	1	NA
Moxifloxacin	0.25->16	1	2	95.2
Gatifloxacin	0.5->16	1	4	NA
Clindamycin	0.06-8	0.06	2	95.2
Metronidazole	≤0.12-2	0.25	1	100
Peptostreptococcus spp. (n = 52)
Besifloxacin	0.06-2	0.25	0.5	NA
Moxifloxacin	0.25-4	0.25	0.5	98.1
Ciprofloxacin	0.5->8	2	4	NA
Clindamycin	0.06->8	0.25	>8	88.5
Metronidazole	≤0.03->16	0.5	1	98.1
Prevotella spp. (n = 20)
Besifloxacin	0.06-16	1	4	NA
Moxifloxacin	0.12->16	4	8	45.0
Gatifloxacin	0.25->16	8	16	NA
Clindamycin	≤0.03->8	≤0.03	>8	85.0
Metronidazole	0.25-8	4	4	100.0
Propionibacterium acnes (n = 21)
Besifloxacin	0.12-0.25	0.25	0.25	NA
Moxifloxacin	0.25-0.25	0.25	0.25	100.0
Gatifloxacin	0.25-0.5	0.25	0.5	NA
Clindamycin	≤0.03-2	0.06	0.12	100.0
Metronidazole	>16->16	>16	>16	0

^aPercentage of susceptible isolates (10); breakpoints have not been defined for all agent-species combinations. NA, not applicable.