Which Enterococcus species demonstrates high vancomycin resistance?

Which Enterococcus species demonstrates high vancomycin resistance?

• A. faecium
• B. faecalis
• C. casseliflavus
• D. gallinarum

Answer: (A)

Vancomycin resistance in Enterococcus is driven by acquired gene clusters that change the drug’s binding target, leading to high-level resistance. Enterococcus faecium most commonly carries vanA or vanB, which produce high-level resistance and make vancomycin ineffective. Enterococcus faecalis can show resistance too, but less frequently at the high level seen with faecium. Some species have intrinsic, low-level resistance due to vanC genes (casseliflavus and gallinarum), which is not as severe as the vanA/vanB-mediated resistance. So, the species with the high vancomycin resistance profile is faecium.

Vancomycin resistance in Enterococcus is driven by acquired gene clusters that change the drug’s binding target, leading to high-level resistance. Enterococcus faecium most commonly carries vanA or vanB, which produce high-level resistance and make vancomycin ineffective. Enterococcus faecalis can show resistance too, but less frequently at the high level seen with faecium. Some species have intrinsic, low-level resistance due to vanC genes (casseliflavus and gallinarum), which is not as severe as the vanA/vanB-mediated resistance. So, the species with the high vancomycin resistance profile is faecium.