Role of anaerobic bacteria in aortofemoral graft infection

A 10-year review of specimens of aortofemoral graft infection sent to the microbiology laboratory for cultures of anaerobic bacteria revealed the presence of these organisms in 13 of 16 specimens. Nineteen organisms (1.5 per patient) were isolated: 16 anaerobes and 3 aerobes. The predominant bacteria were anaerobic gram-positive cocci (six isolates), Propionibacterium acnes (five), and Bacteroides fragilis group (four). Polymicrobial infection was present in three patients, all with decubitus ulcers. Conditions predisposing to the infections were present in nine patients and included the presence of preoperative infections in the form of ulcer or toe gangrene in four, decubitus ulcer in three, reoperation in two, and diabetes mellitus in one. These data illustrate the potential importance of anaerobic bacteria in aortofemoral graft infection.