Bacteroides fragilis Abscess Associated With Fat Necrosis Following Breast Augmentation With Autologous Fat Grafting: A Case Report With Review of the Literature.

Autologous fat grafting (AFG) is a popular breast augmentation procedure characterized by high patient satisfaction and low complication rates. Infectious complications are uncommon with this technique, and gram-positive organisms are the predominant pathogens responsible for most cases. We report a rare case of abscess formation due to Bacteroides fragilis infection occurring in the setting of presumed fat necrosis following AFG, as indicated by ultrasound imaging and plastic surgery evaluation. A 52-year-old woman developed a postoperative infection after AFG and abdominal liposuction despite receiving ciprofloxacin for prevention of infectious complications. Initial imaging suggested postsurgical changes, and she was treated with oral amoxicillin-clavulanate. She re-presented two weeks later with fever and worsening bilateral breast pain; repeat imaging revealed bilateral rim-enhancing fluid collections. Aspiration cultures grew Bacteroides fragilis. The patient initially improved with intravenous (IV) antibiotics followed by oral metronidazole; cefadroxil was additionally prescribed to provide empiric coverage for gram-positive organisms, given prior antibiotic exposure that may have affected culture results. However, the patient subsequently developed recurrent disease and ultimately required incision and drainage. This case highlights a rare anaerobic infection after AFG and emphasizes the need for early recognition and appropriate antimicrobial coverage.