Resistance to linezolid is rare in clinical isolates of Enterococcus faecalis. A strain resistant to this antimicrobial but susceptible to vancomycin was found to cause central venous catheter colonization in a patient who never received linezolid.
CASE REPORTA 66-year-old man with chronic pulmonary disease and coronary artery disease underwent transhiatal esophagectomy with gastric pull-through for esophageal carcinoma. His postoperative course was complicated by respiratory failure, necessitating mechanical ventilation for nearly 3 months. He also developed Pseudomonas aeruginosa ventilator-associated pneumonia, urinary tract infection, and central venous catheter-associated bloodstream infection. His Pseudomonas infections were treated with courses of piperacillin-tazobactam, imipenem plus ciprofloxacin, and imipenem plus gentamicin.Approximately 2 weeks after completion of the treatment for the Pseudomonas infections, a blood culture drawn through a central venous catheter grew Enterococcus faecalis susceptible to ampicillin and vancomycin but resistant to linezolid and quinupristin-dalfopristin (Table 1). Simultaneous blood culture obtained from a peripheral vein and two cultures obtained from peripheral vein 3 days later were all negative. Perirectal culture yielded an E. faecalis strain with a different antibiogram (Table 1). Pulsed-field gel electrophoresis was performed, which revealed that the perirectal and blood E. faecalis strains were not related (more than a seven-band difference). The patient did not receive antimicrobial treatment for the E. faecalis and remained afebrile and hemodynamically stable. Of note, the patient had never received linezolid or quinupristindalfopristin. At 45 days prior to isolation of the E. faecalis from the central venous catheter, vancomycin-resistant E. faecium was recovered from a perirectal culture. The patient's condition improved, and he was discharged to a long-term care facility after 91 days of hospitalization.