Linezolid-Resistant Enterococcus faecalis Infection Following Prolonged Low-Dosage Linezolid Treatment for Multidrug-Resistant Tuberculosis

To the Editor—Linezolid is a last-resort option for infections caused by multidrug-resistant (MDR) gram-positive pathogens, including vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus. Linezolid resistance can be mediated by chromosomal mutations in ribosomal RNA (rRNA) or protein genes (23S rRNA, rplC, rplD) altering the ribosomal target [1], and by plasmid-encoded ribosomal methylases (eg, Cfr and Cfr[B]) or ribosomal protection proteins (eg, OptrA) [1–3].