Which statement best describes the antimicrobial resistance of the Bacteroides fragilis group?

Which statement best describes the antimicrobial resistance of the Bacteroides fragilis group?

• A. Susceptible to penicillins
• B. Highly antimicrobial-resistant
• C. Susceptible to first-generation cephalosporins
• D. Susceptible to vancomycin

Answer: (B)

Bacteroides fragilis group are anaerobic Gram-negative rods that commonly harbor beta-lactamase enzymes and other resistance mechanisms, making them resistant to many routinely used antibiotics. This means penicillins and often first-generation cephalosporins are not reliable choices because the beta-lactamases break down these drugs. Vancomycin targets mostly Gram-positive organisms and cannot penetrate the outer membrane of Gram-negative bacteria, so it is ineffective against B. fragilis. While some drugs like metronidazole or certain carbapenems remain active, the overall pattern is that these organisms show substantial resistance across multiple antibiotic classes, which is best described as highly antimicrobial-resistant.

Bacteroides fragilis group are anaerobic Gram-negative rods that commonly harbor beta-lactamase enzymes and other resistance mechanisms, making them resistant to many routinely used antibiotics. This means penicillins and often first-generation cephalosporins are not reliable choices because the beta-lactamases break down these drugs. Vancomycin targets mostly Gram-positive organisms and cannot penetrate the outer membrane of Gram-negative bacteria, so it is ineffective against B. fragilis. While some drugs like metronidazole or certain carbapenems remain active, the overall pattern is that these organisms show substantial resistance across multiple antibiotic classes, which is best described as highly antimicrobial-resistant.