TABLE 3.
In vitro activities of ceftazidime-avibactam and comparative agents against anaerobic species isolated at baseline for all randomized patientsa
| Baseline pathogen and agent (no. of pathogens tested) | MIC (mg/liter) |
||
|---|---|---|---|
| Range | MIC50 | MIC90 | |
| Bacteroides fragilis group (96) | |||
| Ceftazidime-avibactam | 1 to 32 | 4 | 8 |
| Ceftazidime | 4 to >128 | 32 | >128 |
| Amoxicillin-clavulanate | 0.25 to 16 | 0.5 | 4 |
| Ampicillin | 1 to >128 | 32 | >128 |
| Clindamycin | ≤0.015 to >32 | 1 | >32 |
| Meropenem | 0.06 to 8 | 0.12 | 4 |
| Metronidazole | 0.25 to 8 | 1 | 2 |
| Other Bacteroides fragilis group (163)b | |||
| Ceftazidime-avibactam | 2 to >128 | 64 | 128 |
| Ceftazidime | 8 to >128 | >128 | >128 |
| Amoxicillin-clavulanate | 0.25 to >128 | 1 | 8 |
| Ampicillin | 1 to >128 | 32 | >128 |
| Clindamycin | 0.03 to >32 | 8 | >32 |
| Meropenem | 0.06 to 2 | 0.25 | 1 |
| Metronidazole | 0.25 to 8 | 2 | 4 |
| Other Bacteroides spp. (21)c | |||
| Ceftazidime-avibactam | ≤0.06 to 64 | 16 | 64 |
| Ceftazidime | 0.12 to >128 | 32 | >128 |
| Amoxicillin-clavulanate | ≤0.06 to 8 | 0.5 | 2 |
| Ampicillin | ≤0.06 to >128 | 16 | >128 |
| Clindamycin | ≤0.015 to >32 | 2 | >32 |
| Meropenem | ≤0.015 to 2 | 0.25 | 1 |
| Metronidazole | 0.12 to 8 | 1 | 2 |
| Clostridium perfringens (14) | |||
| Ceftazidime-avibactam | ≤0.06 to ≤0.06 | ≤0.06 | ≤0.06 |
| Ceftazidime | 0.25 to 8 | 1 | 4 |
| Amoxicillin-clavulanate | ≤0.06 to 0.12 | ≤0.06 | ≤0.06 |
| Ampicillin | ≤0.06 to 0.25 | ≤0.06 | 0.12 |
| Clindamycin | 0.03 to >32 | 1 | 4 |
| Meropenem | ≤0.015 to 0.25 | ≤0.015 | 0.03 |
| Metronidazole | 0.25 to 4 | 1 | 4 |
| Other Clostridium spp. (28)d | |||
| Ceftazidime-avibactam | ≤0.06 to >128 | 16 | >128 |
| Ceftazidime | 2 to >128 | 32 | >128 |
| Amoxicillin-clavulanate | ≤0.06 to 2 | 0.5 | 1 |
| Ampicillin | ≤0.06 to 64 | 0.5 | 8 |
| Clindamycin | 0.06 to >32 | 1 | >32 |
| Meropenem | ≤0.015 to 4 | 1 | 4 |
| Metronidazole | ≤0.06 to 4 | 0.5 | 2 |
| Eggerthella lenta (13) | |||
| Ceftazidime-avibactam | >128 to >128 | >128 | >128 |
| Ceftazidime | >128 to >128 | >128 | >128 |
| Amoxicillin-clavulanate | 0.25 to 2 | 1 | 1 |
| Ampicillin | 1 to 4 | 2 | 2 |
| Clindamycin | 0.06 to >32 | 0.5 | >32 |
| Meropenem | 0.25 to 1 | 0.25 | 0.5 |
| Metronidazole | 0.5 to 16 | 2 | 4 |
| Parvimonas micra (16) | |||
| Ceftazidime-avibactam | ≤0.06 to 4 | ≤0.06 | 0.5 |
| Ceftazidime | 0.12 to 8 | 0.5 | 2 |
| Amoxicillin-clavulanate | ≤0.06 to 0.5 | ≤0.06 | 0.25 |
| Ampicillin | ≤0.06 to 8 | ≤0.06 | 0.25 |
| Clindamycin | 0.06 to 4 | 0.25 | 0.5 |
| Meropenem | ≤0.015 to 0.25 | 0.03 | 0.12 |
| Metronidazole | 0.12 to 1 | 0.5 | 1 |
| Prevotella spp. (21)e | |||
| Ceftazidime-avibactam | ≤0.06 to 8 | 0.5 | 4 |
| Ceftazidime | 0.12 to 128 | 2 | 16 |
| Amoxicillin-clavulanate | ≤0.06 to 1 | 0.12 | 0.5 |
| Ampicillin | ≤0.06 to 16 | 0.25 | 8 |
| Clindamycin | ≤0.015 to >32 | ≤0.015 | >32 |
| Meropenem | ≤0.015 to 0.25 | 0.03 | 0.12 |
| Metronidazole | 0.12 to 8 | 1 | 4 |
Total of 1,066 randomized patients. Data are provided for pathogens identified in at least 10 patients.
Other Bacteroides fragilis group includes Bacteroides caccae (n = 3), Bacteroides ovatus (n = 41), Bacteroides stercoris (n = 11), Bacteroides thetaiotaomicron (n = 47), Bacteroides uniformis (n = 15), Bacteroides vulgatus (n = 16), Parabacteroides distasonis (n = 29), and Parabacteroides merdae (n = 1).
Other Bacteroides spp. includes Bacteroides (n = 5), Bacteroides dorei (n = 4), Bacteroides faecis (n = 4), Bacteroides nordii (n = 3), Bacteroides salyersiae (n = 1), Bacteroides splanchnicus (n = 3), and Bacteroides xylanisolvens (n = 1).
Other Clostridium spp. includes Clostridium aldenense (n = 1), Clostridium bolteae (n = 1), Clostridium citroniae (n = 1), Clostridium clostridioforme (n = 3), Clostridium hathewayi (n = 3), Clostridium innocuum (n = 9), Clostridium ramosum (n = 6), Clostridium septicum (n = 1), Clostridium sporogenes (n = 1), and Clostridium symbiosum (n = 2).
Prevotella spp. includes Prevotella (n = 1), Prevotella bivia (n = 2), Prevotella buccae (n = 6), Prevotella denticola (n = 2), Prevotella heparinolytica (1), Prevotella intermedia (n = 4), Prevotella melaninogenica (n = 2), Prevotella nigrescens (2), and Prevotella oralis (n = 1).