Infections due to vancomycin-resistant Enterococcus faecium resistant to linezolid

Area of Science:

• Infectious Diseases
• Microbiology
• Pharmacology

Background:

• Linezolid is a crucial antibiotic for treating infections caused by vancomycin-resistant enterococci (VRE).
• Early clinical trials indicated a low incidence of resistance emergence during linezolid therapy.
• VRE infections pose a significant challenge, particularly in immunocompromised patients.

Observation:

• This report details five cases of VRE infections treated with linezolid where resistant organisms were isolated during therapy.
• Four of these patients were transplant recipients undergoing extended linezolid treatment.
• Three cases were associated with treatment failure, highlighting potential therapeutic limitations.

Findings:

• One out of 45 patients treated with linezolid developed resistance during the course of therapy.
• The emergence of resistance was more frequently observed in transplant patients receiving prolonged linezolid treatment.
• Clinical outcomes included treatment failure in three of the reported cases.

Implications:

• The findings suggest that while rare, linezolid resistance can emerge in VRE infections.
• Protracted linezolid therapy, especially in immunocompromised hosts like transplant patients, may be associated with a higher risk of resistance.
• Routine antibiotic susceptibility testing for linezolid should be considered at the initiation of therapy for VRE infections to guide treatment decisions and monitor for resistance.