TABLE 5.

Comparison of the in vitro activities of the various antimicrobial agents against isolates of the B. fragilis and non-B. fragilis species

Antimicrobial agent and species groups	No. of isolates tested	MIC (μg/ml)				%Sa
		Range	Mode	50%	90%
Piperacillin-tazobactam
B. fragilis	180	0.06–32	0.12	0.12	1	100
Non-B. fragilis	221	0.06–16	2	0.5	4	100
Ampicillin-sulbactam
B. fragilis	180	0.5–64	1	2	8	92
Non-B. fragilis	221	0.03–64	1	2	16	87
Penicillin G
B. fragilis	180	0.5–32	8	8	32	0
Non-B. fragilis	221	0.015–32	32	8	32	0
Cefoxitin
B. fragilis	180	0.25–32	4	4	16	93
Non-B. fragilis	221	0.015–32	4	4	16	91
Imipenem
B. fragilis	180	0.015–8	0.03	0.06	0.25	99.4
Non-B. fragilis	221	0.015–2	0.12	0.06	0.25	100
Meropenem
B. fragilis	180	0.03–32	0.06	0.12	0.5	98.3
Non-B. fragilis	221	0.015–8	0.12	0.12	0.5	99.1
Ciprofloxacin
B. fragilis	180	0.5–32	4	4	32	13
Non-B. fragilis	221	0.03–32	32	16	32	6
Trovafloxacin
B. fragilis	180	0.015–4	0.25	0.25	2	93
Non-B. fragilis	221	0.015–16	0.5	0.5	2	92
Clindamycin
B. fragilis	180	0.015–16	0.25	0.25	16	77
Non-B. fragilis	221	0.015–16	16	1	16	67
Metronidazole
B. fragilis	180	0.12–2	0.5	0.5	1	100
Non-B. fragilis	221	0.12–4	0.5	0.5	1	100

^aPercent susceptible isolates.