Microbiology An isolate from a wound culture is a Gram-negative rod identified as Bacteroides fragilis. Anaerobic infection with B. fragilis is characterized by A A foul-smelling discharge B A black exudate in the wound C An exquisite susceptibility to penicillin D A heme-pigmented colony formation 💡 Explanation An isolate from a wound culture is a Gram-negative rod identified as Bacteroides fragilis. Anaerobic infection with B. fragilis is characterized by ✓ Correct Answer: A. A foul-smelling discharge