Table 3.

Percent resistance of Bacteroides fragilis group isolates and other anaerobes to antimicrobial agents^a,b

Antimicrobial	MIC breakpoint (μg/ml)		% resistance to antimicrobial
	Susceptible	Resistant	B. fragilis	B. thetaiotaomicron	P. distasonis	B. ovatus	B. vulgatus	B. fragilis group	Prevotella spp.	Fusobacterium spp.	Clostridium spp.	Anaerobic Gram-positive cocci
Ampicillin-sulbactam	≤8/4	≥32/16	2.8–11	4.9–15	15–20.6	2–8	3–25		0		0	0
Amoxicillin-clavulanate	≤4/2	≥16/8	4–37	12–37	21	18	14	10–20	0–19	0–11	0–5	0–6
Piperacillin-tazobactam	≤32/4	≥128/4	0–5	0–12	0–14	0	1.1–7	0–8	0–1	0	0	0–3
Cefoxitin	≤16	≥64	4–25	6.8–68	11–60	18–59	11–20	17–33	0–3	0	16–35	0–2
Ertapenem	≤4	≥16	1.4–10	1.3–3	0–6	2–2.2	0–2		0	0	0–4	0
Imipenem	≤4	≥16	0.3–7	0–7	0–1	0	0–7	<1–1	0–6	4	15	0
Meropenem	<4	≥16	1.2–22	0–3	0–1	0	0			8	0–5	0
Doripenem	≤4	≥16	1.3–12	0–3	0	0	0			0	0	0
Clindamycin	≤2	≥8	10–42	39.8–60	14.3–64	36–45.5	40–54	32–52	13–33	8–31	16–25	5–27
Moxifloxacin	≤2	≥8	10–41	13–75	12.5–52	8–87	21–74	14–57	11–42	10–25	7–53	4–36
Tigecycline	≤4	≥16	2–11	0–5.8	0–3.2	2–5.2	0–5	2–13	0	0	14	0

^aIncluding intermediate-resistant strains. Metronidazole is not included since >99% of Gram-negative strains are susceptible.

^bAdapted from reference 78 with permission from Elsevier.