| Gram Stain | |||||||
  Fatty acid peaks for acetic acid and proprionic acid, but little or no isobutyric, butyric, or isovaleric acid | Antibiotic sensitivity
|  Sensitivity to tetracycline; resistance to erythromycin, metronidazole, penicillin, augmentin, neomycin, and kanamycin | Bacteroides fragilis | B. fragilis is a cause for abdominal sepsis
| |