Risk factors and outcome associated with the acquisition of linezolid-resistant Enterococcus faecalis

Abstract

Objectives: Linezolid is a synthetic oxazolidinone antibiotic frequently used to treat vancomycin-resistant enterococcal infections. Vancomycin-susceptible Enterococcus faecalis can develop resistance to linezolid in environments with excessive linezolid use. The aim of this study was to define risk factors and outcome associated with the acquisition of linezolid-resistant E. faecalis (LREfs).

Methods: A retrospective case-control study was designed including patients hospitalised from January 2014 to October 2017 at Hospital Civil de Guadalajara 'Fray Antonio Alcalde' in Guadalajara, Mexico. A total of 50 patients culture-positive for LREfs and 100 control patients hospitalised in the same room and time as the cases were included. Clinical and demographic data were collected and analysed.

Results: Risk factors for the presence of LREfs included prior linezolid use [odds ratio (OR) = 6.74], prior clindamycin use (OR = 6.72) and previous surgery (OR = 5.79). The mortality rate was 18% for LREfs cases versus 9% for controls.

Conclusion: LREfs has emerged and spread in our hospital, an environment in which linezolid use is considerable. Risk factors for LREfs are prior antibiotic use, including linezolid, and previous surgery.

Keywords: Enterococcus faecalis; Linezolid-resistant; Risk factors.