- Bacteroides fragilis are obligate anaerobic Gram Negative Rods in the Bacteroidaceae family
- Bacteroides fragilis has a capsule
- Bacteroides fragilis secretes an Enterotoxin (BFT)
- However, does not contain Lipid A or Endotoxin (unlike most other Gram Negative Bacteria)
- Bacteroides fragilis is a normal colonizer of the Gastrointestinal Tract (25% of intestinal flora)
- Low virulence unless intestinal wall is perforated
- May also be associated with Inflammatory Bowel Disease flares
- Bacteroides fragilis rarely colonizes the mouth (uncommon cause of Aspiration Pneumonia)
- Intraabdominal anaerobic Bacterial Infections and abscesses
- Bacteroides fragilis is found in most intraabdominal anaerobic infections
- Among the most commonly isolated Bacteria in anaerobic bacteremia
- Occurs with Bowel perforation, Mesenteric Ischemia, Pelvic Inflammatory Disease, Septic Abortion
- Wound Infections
- Source control with abscess drainage
- Antibiotics with highest efficacy against Bacteroides fragilis (lower resistance rates)
- Antibiotics with high Bacteroides fragilis resistance rates (low susceptibility)
- Bacteroides fragilis bacteremia is associated with mortality as high as 30%
- lsaghir (2023) Bacteroides fragilis, StatPearls, Treasure Island, Fl