TABLE 1.
Agar dilution MICs against 431 strains
| Strain and drug | MIC range (μg/ml) | MIC50 (μg/ml) | MIC90 (μg/ml) |
|---|---|---|---|
| Bacteroides fragilis (47/47)a | |||
| Ertapenem | 0.125–>16.0 | 0.25 | 2.0 |
| Imipenem | 0.03–>8.0 | 0.25 | 1.0 |
| Meropenem | 0.125–>8.0 | 0.125 | 0.5 |
| Ceftriaxone | 4.0–>64.0 | 64.0 | 64.0 |
| Piperacillin | 2.0–>128.0 | 16.0 | >128.0 |
| Piperacillin-tazobactam | ≤0.125–>128.0 | 1.0 | 4.0 |
| Clindamycin | 0.125–>32.0 | 2.0 | >32.0 |
| Metronidazole | 0.5–4.0 | 1.0 | 2.0 |
| Bacteroides thetaiotaomicron (33/30) | |||
| Ertapenem | 0.06–2.0 | 1.0 | 1.0 |
| Imipenem | 0.125–4.0 | 0.25 | 0.5 |
| Meropenem | 0.25–0.5 | 0.25 | 0.5 |
| Ceftriaxone | 64.0–>64.0 | >64.0 | >64.0 |
| Piperacillin | 32.0–>128.0 | 64.0 | 128.0 |
| Piperacillin-tazobactam | 1.0–32.0 | 8.0 | 32.0 |
| Clindamycin | 0.5–>32.0 | 4.0 | 16.0 |
| Metronidazole | 0.5–4.0 | 2.0 | 2.0 |
| Bacteroides ovatus (17/17) | |||
| Ertapenem | 0.5–8.0 | 1.0 | 1.0 |
| Imipenem | 0.125–1.0 | 0.25 | 0.5 |
| Meropenem | 0.25–2.0 | 0.5 | 0.5 |
| Ceftriaxone | 32.0–>64.0 | >64.0 | >64.0 |
| Piperacillin | 16.0–>128.0 | 32.0 | >128.0 |
| Piperacillin-tazobactam | 2.0–8.0 | 4.0 | 8.0 |
| Clindamycin | 2.0–>32.0 | 4.0 | >32.0 |
| Metronidazole | 0.5–2.0 | 2.0 | 2.0 |
| Bacteroides distasonis (10/5) | |||
| Ertapenem | 0.5–2.0 | 1.0 | 2.0 |
| Imipenem | 0.125–2.0 | 0.5 | 1.0 |
| Meropenem | 0.125–1.0 | 0.25 | 0.5 |
| Ceftriaxone | 2.0–>64.0 | 32.0 | >64.0 |
| Piperacillin | 8.0–>128.0 | 64.0 | >128.0 |
| Piperacillin-tazobactam | 2.0–32.0 | 4.0 | 8.0 |
| Clindamycin | 0.25–>32.0 | 8.0 | 16.0 |
| Metronidazole | 1.0–2.0 | 1.0 | 2.0 |
| Bacteroides vulgatus (11/11) | |||
| Ertapenem | 0.125–4.0 | 0.125 | 2.0 |
| Imipenem | 0.25–4.0 | 0.5 | 4.0 |
| Meropenem | 0.25–4.0 | 0.25 | 1.0 |
| Ceftriaxone | 8.0–>64.0 | 16.0 | >64.0 |
| Piperacillin | 8.0–>128.0 | 16.0 | >128.0 |
| Piperacillin-tazobactam | 2.0–16.0 | 4.0 | 16.0 |
| Clindamycin | 0.03–>32.0 | 0.5 | 2.0 |
| Metronidazole | 0.5–2.0 | 1.0 | 2.0 |
| Miscellaneous Bacteroides fragilis groupb (15/14) | |||
| Ertapenem | 0.06–2.0 | 1.0 | 1.0 |
| Imipenem | 0.06–1.0 | 0.25 | 0.5 |
| Meropenem | 0.06–0.5 | 0.25 | 0.5 |
| Ceftriaxone | 0.25–>64.0 | 32.0 | >64.0 |
| Piperacillin | 1.0–>128.0 | 32.0 | >128.0 |
| Piperacillin-tazobactam | ≤0.125–16.0 | 2.0 | 8.0 |
| Clindamycin | 0.06–>32.0 | 4.0 | >32.0 |
| Metronidazole | 0.25–4.0 | 1.0 | 2.0 |
| All Bacteroides fragilis group (133/124) | |||
| Ertapenem | 0.06–>16.0 | 0.5 | 2.0 |
| Imipenem | 0.03–>8.0 | 0.25 | 1.0 |
| Meropenem | 0.06–>8.0 | 0.25 | 0.5 |
| Ceftriaxone | 0.25–>64.0 | 64.0 | >64.0 |
| Piperacillin | 1.0–>128.0 | 32.0 | >128.0 |
| Piperacillin-tazobactam | ≤0.125–>128.0 | 4.0 | 16.0 |
| Clindamycin | 0.03–>32.0 | 2.0 | >32.0 |
| Metronidazole | 0.25–4.0 | 1.0 | 2.0 |
| Prevotella bivia (30/24) | |||
| Ertapenem | 0.125–0.5 | 0.25 | 0.5 |
| Imipenem | ≤0.016–0.125 | 0.06 | 0.06 |
| Meropenem | 0.06–0.5 | 0.06 | 0.125 |
| Ceftriaxone | 0.25–>64.0 | 8.0 | 64.0 |
| Piperacillin | 1.0–128.0 | 8.0 | 64.0 |
| Piperacillin-tazobactam | ≤0.125–0.25 | ≤0.125 | ≤0.125 |
| Clindamycin | ≤0.016–0.06 | 0.03 | 0.06 |
| Metronidazole | 0.5–8.0 | 4.0 | 4.0 |
| Prevotella corporis (10/3) | |||
| Ertapenem | 0.016–0.125 | 0.03 | 0.125 |
| Imipenem | ≤0.016–0.06 | 0.03 | 0.06 |
| Meropenem | 0.008–0.125 | 0.06 | 0.06 |
| Ceftriaxone | ≤0.125–32.0 | ≤0.125 | 16.0 |
| Piperacillin | 0.25–64.0 | 0.5 | 16.0 |
| Piperacillin-tazobactam | ≤0.125–0.25 | ≤0.125 | ≤0.125 |
| Clindamycin | ≤0.016–32.0 | ≤0.016 | 0.03 |
| Metronidazole | ≤0.125–1.0 | 0.5 | 1.0 |
| Prevotella melaninogenica (10/9) | |||
| Ertapenem | 0.06–0.5 | 0.125 | 0.25 |
| Imipenem | ≤0.016–0.03 | 0.03 | 0.03 |
| Meropenem | 0.125–0.06 | 0.03 | 0.06 |
| Ceftriaxone | ≤0.125–64.0 | 1.0 | 32.0 |
| Piperacillin | 1.0–64.0 | 4.0 | 32.0 |
| Piperacillin-tazobactam | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Clindamycin | ≤0.016–≤0.016 | ≤0.016 | ≤0.016 |
| Metronidazole | 0.5–1.0 | 0.5 | 1.0 |
| Prevotella intermedia (10/6) | |||
| Ertapenem | 0.03–0.125 | 0.06 | 0.125 |
| Imipenem | ≤0.016–0.06 | 0.03 | 0.06 |
| Meropenem | 0.03–0.06 | 0.06 | 0.06 |
| Ceftriaxone | ≤0.125–32.0 | 2.0 | 8.0 |
| Piperacillin | 0.25–32.0 | 8.0 | 32.0 |
| Piperacillin-tazobactam | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Clindamycin | ≤0.016–≤0.016 | ≤0.016 | ≤0.016 |
| Metronidazole | 0.25–1.0 | 0.5 | 1.0 |
| Miscellaneous strainsc (20/13) | |||
| Ertapenem | 0.008–0.5 | 0.125 | 0.5 |
| Imipenem | ≤0.016–0.125 | 0.06 | 0.125 |
| Meropenem | 0.008–0.25 | 0.125 | 0.25 |
| Ceftriaxone | ≤0.125–64.0 | 1.0 | 64.0 |
| Piperacillin | ≤0.125–128.0 | 4.0 | 128.0 |
| Piperacillin-tazobactam | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Clindamycin | ≤0.016–0.03 | ≤0.016 | 0.03 |
| Metronidazole | ≤0.125–4.0 | 2.0 | 4.0 |
| Prevotella-Porphyromonas (80/55) | |||
| Ertapenem | 0.008–0.5 | 0.125 | 0.5 |
| Imipenem | ≤0.016–0.125 | 0.03 | 0.125 |
| Meropenem | 0.008–0.5 | 0.06 | 0.125 |
| Ceftriaxone | ≤0.125–>64.0 | 4.0 | 64.0 |
| Piperacillin | ≤0.125–128.0 | 8.0 | 64.0 |
| Piperacillin-tazobactam | ≤0.125–0.25 | ≤0.125 | ≤0.125 |
| Clindamycin | ≤0.016–32.0 | ≤0.016 | 0.03 |
| Metronidazole | ≤0.125–8.0 | 2.0 | 4.0 |
| Fusobacterium necrophorum (10/0) | |||
| Ertapenem | ≤0.004–0.016 | ≤0.004 | 0.008 |
| Imipenem | ≤0.016–0.03 | ≤0.016 | ≤0.016 |
| Meropenem | ≤0.008–0.016 | ≤0.008 | 0.016 |
| Ceftriaxone | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Piperacillin | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Piperacillin-tazobactam | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Clindamycin | 0.03–0.06 | 0.06 | 0.06 |
| Metronidazole | ≤0.125–1.0 | 0.25 | 0.5 |
| Fusobacterium nucleatum (10/1) | |||
| Ertapenem | ≤0.004–2.0 | 0.5 | 2.0 |
| Imipenem | ≤0.016–0.25 | 0.03 | 0.06 |
| Meropenem | ≤0.008–1.0 | 0.25 | 1.0 |
| Ceftriaxone | ≤0.125–4.0 | 1.0 | 2.0 |
| Piperacillin | ≤0.125–>128.0 | ≤0.125 | 0.25 |
| Piperacillin-tazobactam | ≤0.125–≤0.125 | ≤0.125 | ≤0.125 |
| Clindamycin | 0.03–0.125 | 0.06 | 0.125 |
| Metronidazole | ≤0.125–0.5 | ≤0.125 | 0.25 |
| Fusobacterium mortiferum (11/2) | |||
| Ertapenem | 0.03–0.5 | 0.125 | 0.25 |
| Imipenem | 0.25–1.0 | 0.5 | 1.0 |
| Meropenem | 0.06–0.5 | 0.25 | 0.5 |
| Ceftriaxone | 32.0–>64.0 | >64.0 | >64.0 |
| Piperacillin | 0.25–>128.0 | 1.0 | >128.0 |
| Piperacillin-tazobactam | 0.25–64.0 | 0.5 | 1.0 |
| Clindamycin | 0.06–0.125 | 0.125 | 0.125 |
| Metronidazole | ≤0.125–0.5 | 0.25 | 0.5 |
| Fusobacterium varium (10/2) | |||
| Ertapenem | 0.06–8.0 | 0.125 | 1.0 |
| Imipenem | 0.5–2.0 | 0.5 | 1.0 |
| Meropenem | 0.06–8.0 | 0.125 | 8.0 |
| Ceftriaxone | ≤0.125–>64.0 | 4.0 | 16.0 |
| Piperacillin | 2.0–>128.0 | 16.0 | 64.0 |
| Piperacillin-tazobactam | 1.0–>128.0 | 8.0 | 16.0 |
| Clindamycin | 1.0–16.0 | 8.0 | 16.0 |
| Metronidazole | 0.25–2.0 | 0.5 | 0.5 |
| Fusobacteria (41/5) | |||
| Ertapenem | ≤0.004–8.0 | 0.06 | 1.0 |
| Imipenem | ≤0.016–2.0 | 0.25 | 1.0 |
| Meropenem | ≤0.008–8.0 | 0.125 | 1.0 |
| Ceftriaxone | ≤0.125–>64.0 | 2.0 | >64.0 |
| Piperacillin | ≤0.125–>128.0 | 0.25 | 64.0 |
| Piperacillin-tazobactam | ≤0.125–>128.0 | 0.25 | 8.0 |
| Clindamycin | 0.03–16.0 | 0.06 | 8.0 |
| Metronidazole | ≤0.125–2.0 | 0.25 | 0.5 |
| Peptostreptococcid (53/0) | |||
| Ertapenem | ≤0.004–4.0 | 0.125 | 1.0 |
| Imipenem | ≤0.016–2.0 | 0.03 | 0.5 |
| Meropenem | ≤0.008–4.0 | 0.06 | 0.5 |
| Ceftriaxone | ≤0.125–32.0 | 0.5 | 16.0 |
| Piperacillin | ≤0.125–32.0 | 0.25 | 2.0 |
| Piperacillin-tazobactam | ≤0.125–16.0 | ≤0.125 | 2.0 |
| Clindamycin | 0.03–>32.0 | 0.25 | 4.0 |
| Metronidazole | ≤0.125–>16.0 | 1.0 | 2.0 |
| Propionibacterium spp. (21/0) | |||
| Ertapenem | 0.06–0.5 | 0.25 | 0.5 |
| Imipenem | ≤0.016–0.03 | 0.03 | 0.03 |
| Meropenem | 0.03–0.5 | 0.25 | 0.5 |
| Ceftriaxone | ≤0.125–1.0 | 0.5 | 0.5 |
| Piperacillin | 0.5–2.0 | 1.0 | 2.0 |
| Piperacillin-tazobactam | ≤0.125–2.0 | 1.0 | 2.0 |
| Clindamycin | 0.06–0.25 | 0.125 | 0.125 |
| Metronidazole | >16.0–>16.0 | >16.0 | >16.0 |
| Eubacterium spp. (16/0) | |||
| Ertapenem | 0.06–2.0 | 1.0 | 1.0 |
| Imipenem | ≤0.016–0.5 | 0.5 | 0.5 |
| Meropenem | 0.06–4.0 | 0.25 | 0.5 |
| Ceftriaxone | 0.25–>64.0 | 32.0 | >64.0 |
| Piperacillin | 0.25–32.0 | 16.0 | 32.0 |
| Piperacillin-tazobactam | ≤0.125–32.0 | 16.0 | 16.0 |
| Clindamycin | 0.03–>32.0 | 0.5 | 4.0 |
| Metronidazole | 0.25–>16.0 | 0.5 | 1.0 |
| Lactobacillus spp. (11/0) | |||
| Ertapenem | 0.06–>16.0 | 16.0 | >16.0 |
| Imipenem | 0.03–4.0 | 2.0 | 4.0 |
| Meropenem | 0.03–>8.0 | 8.0 | >8.0 |
| Ceftriaxone | 1.0–>64.0 | 64.0 | >64.0 |
| Piperacillin | 1.0–8.0 | 2.0 | 8.0 |
| Piperacillin-tazobactam | 1.0–4.0 | 2.0 | 4.0 |
| Clindamycin | 0.03–4.0 | 0.5 | 4.0 |
| Metronidazole | 1.0–>16.0 | >16.0 | >16.0 |
| Other gram-positive non-spore-forming rodse (16/0) | |||
| Ertapenem | 0.03–2.0 | 0.25 | 1.0 |
| Imipenem | ≤0.016–0.5 | 0.25 | 0.25 |
| Meropenem | 0.03–1.0 | 0.125 | 0.5 |
| Ceftriaxone | ≤0.125–8.0 | 0.5 | 2.0 |
| Piperacillin | ≤0.125–4.0 | 0.5 | 2.0 |
| Piperacillin-tazobactam | ≤0.125–4.0 | 0.5 | 2.0 |
| Clindamycin | ≤0.016–16.0 | 0.06 | 4.0 |
| Metronidazole | 0.5–>16.0 | >16.0 | >16.0 |
| Clostridium perfringens (22/0) | |||
| Ertapenem | 0.008–0.25 | 0.06 | 0.125 |
| Imipenem | ≤0.016–0.25 | 0.06 | 0.125 |
| Meropenem | ≤0.008–0.125 | 0.016 | 0.03 |
| Ceftriaxone | 0.25–16.0 | 2.0 | 8.0 |
| Piperacillin | ≤0.125–2.0 | 0.25 | 1.0 |
| Piperacillin-tazobactam | ≤0.125–1.0 | 0.25 | 0.5 |
| Clindamycin | 0.125–>32.0 | 2.0 | 4.0 |
| Metronidazole | 0.125–2.0 | 1.0 | 2.0 |
| Clostridium difficile (10/0) | |||
| Ertapenem | 4.0–8.0 | 4.0 | 8.0 |
| Imipenem | 2.0–4.0 | 2.0 | 4.0 |
| Meropenem | 2.0–4.0 | 2.0 | 4.0 |
| Ceftriaxone | 32.0–>64.0 | 32.0 | >64.0 |
| Piperacillin | 8.0–32.0 | 16.0 | 32.0 |
| Piperacillin-tazobactam | 8.0–32.0 | 8.0 | 16.0 |
| Clindamycin | 2.0–>32.0 | 4.0 | >32.0 |
| Metronidazole | 0.25–0.5 | 0.25 | 0.25 |
| Other clostridiaf (28/0) | |||
| Ertapenem | 0.008–4.0 | 0.5 | 4.0 |
| Imipenem | 0.06–4.0 | 0.5 | 2.0 |
| Meropenem | 0.016–2.0 | 0.25 | 2.0 |
| Ceftriaxone | 0.25–>64.0 | 4.0 | 16.0 |
| Piperacillin | 0.25–16.0 | 1.0 | 16.0 |
| Piperacillin-tazobactam | ≤0.125–16.0 | 0.5 | 4.0 |
| Clindamycin | 0.06–>32.0 | 2.0 | 16.0 |
| Metronidazole | ≤0.125–2.0 | 1.0 | 1.0 |
| All strains (431/184) | |||
| Ertapenem | ≤0.004–>16.0 | 0.25 | 2.0 |
| Imipenem | ≤0.016–>8.0 | 0.125 | 1.0 |
| Meropenem | ≤0.008–>8.0 | 0.125 | 1.0 |
| Ceftriaxone | ≤0.125–>64.0 | 16.0 | >64.0 |
| Piperacillin | ≤0.125–>128.0 | 4.0 | 64.0 |
| Piperacillin-tazobactam | ≤0.125–>128.0 | 0.5 | 16.0 |
| Clindamycin | ≤0.016–>32.0 | 0.5 | 16.0 |
| Metronidazole | ≤0.125–>16.0 | 1.0 | >16.0 |
a
Number of strains tested/number of strains β-lactamase positive.
b
Bacteroides caccae (2), Bacteroides merdae (1), Bacteroides splanchnicus (3), Bacteroides stercoris (7), and Bacteroides fragilis group (2).
c
Prevotella oris (1), Prevotella denticola (1), Prevotella buccae (8), Prevotella disiens (8), and Porphyromonas asaccharolytica (2).
d
Peptostreptococcus asaccharolyticus (9), Peptostreptococcus magnus (15), Peptostreptococcus anaerobius (13), Peptostreptococcus micros (4), Peptostreptococcus prevotii (1), and Peptostreptococcus tetradius (11).
e
Actinomyces spp. (6) and Bifidobacterium spp. (8).
f
Clostridium tertium (1), Clostridium bifermentans (2), Clostridium sordellii (6), Clostridium cadaveris (1), Clostridium baratii (1), Clostridium butyricum (1), Clostridium chlostridioforme (1), Clostridium hastiforme (1), Clostridium innocuum (3), Clostridium paraputrificum (1), Clostridium ramosum (3), and Clostridium spp. (7).