Enterococcus faecium is isolated from a blood culture of a patient with a central venous catheter. Sensitivity testing shows high-level resistance to ampicillin (MIC >16 µg/mL) and vancomycin (VRE, MIC >32 µg/mL). The most appropriate antibiotic for this VRE bacteraemia is:
- A Linezolid ✓
- B Meropenem
- C Teicoplanin
- D Clindamycin
Explanation
Vancomycin-resistant Enterococcus (VRE) — most commonly E. faecium — is mediated by vanA (resistance to both vancomycin and teicoplanin) or vanB (vancomycin resistant, teicoplanin susceptible) gene clusters encoding D-Ala–D-Lac ligases. For VRE bacteraemia, linezolid (an oxazolidinone) is a first-line option, acting by inhibiting the 70S ribosomal initiation complex. Daptomycin is an alternative for non-pulmonary VRE infections. Meropenem has no significant activity against Enterococcus. Teicoplanin has cross-resistance with vanA phenotype VRE. Clindamycin has intrinsic activity limitations in Enterococcus.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.