Which statement about Bacteroides fragilis is NOT true?

Which statement about Bacteroides fragilis is NOT true?

• A. Lipase and lecithinase negative
• B. Anaerobic gram-negative bacillus
• C. Commonly associated with intraabdominal infections
• D. Among the most antimicrobial-sensitive anaerobic bacteria

Answer: (D)

Bacteroides fragilis is well known for its antimicrobial resistance because many strains produce beta-lactamase, which in practice makes penicillins unreliable and means it is not one of the most antimicrobial-sensitive anaerobes. In the clinic, this organism is typically treated with agents that overcome beta-lactamase threats, such as metronidazole, carbapenems, or beta-lactamase inhibitor combinations, rather than with penicillin alone. Despite this resistance profile, it remains an anaerobic gram-negative bacillus and is a common cause of intraabdominal infections, which is why those statements are true. Therefore, the claim that it is among the most antimicrobial-sensitive anaerobic bacteria is not true.

Bacteroides fragilis is well known for its antimicrobial resistance because many strains produce beta-lactamase, which in practice makes penicillins unreliable and means it is not one of the most antimicrobial-sensitive anaerobes. In the clinic, this organism is typically treated with agents that overcome beta-lactamase threats, such as metronidazole, carbapenems, or beta-lactamase inhibitor combinations, rather than with penicillin alone. Despite this resistance profile, it remains an anaerobic gram-negative bacillus and is a common cause of intraabdominal infections, which is why those statements are true. Therefore, the claim that it is among the most antimicrobial-sensitive anaerobic bacteria is not true.