Linezolid is effective against VRE.

• A. Linezolid
• B. Vancomycin
• C. Daptomycin
• D. Ciprofloxacin

Answer: (A)

Linezolid is effective against VRE because it belongs to the oxazolidinone class and inhibits protein synthesis by binding to the 50S ribosomal subunit, preventing formation of the initiation complex. This mechanism is different from what vancomycin targets, so VRE strains—which have altered cell-wall binding sites—are resistant to vancomycin but often remain susceptible to linezolid.

Vancomycin fails against VRE due to resistance mechanisms that modify the vancomycin binding site, so it’s not reliable for these organisms. Daptomycin can be active against some VRE strains, but its effectiveness isn’t universal and resistance can occur; it’s also not the go-to option in all infection sites. Ciprofloxacin generally isn’t active against enterococci because these bacteria have intrinsic and acquired resistance to fluoroquinolones.

So, linezolid provides reliable activity against VRE, making it the best choice among these options.