ABSTRACT
Objective To investigate the molecular epidemiology and infectious risk factors of linezolid-resistant Enterococci (LRE) isolates in the First Affiliated Hospital of Chongqing Medical University.Methods Thirteen LRE isolates were collected from 2011 to 2013 and confirmed by broth dilution susceptibility testing.The minimum inhibitory concentrations (MIC) of twelve antimicrobial agents were analyzed using Vitek 2 compact.The molecular epidemiology of LRE isolates was determined by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and the Diversilab.A casecontrol study was conducted for the analysis of risk factors, and Logistic regression was performed to evaluate the independent risk factors.Results All thirteen LRE isolates showed low-level resistance to linezolid, and most of these isolates were resistant to tetracycline, erythromycin and ciprofloxacin.However, they had high sensitivity to penicillin, ampicillin and tigecycline.Sequence type 480 was predominant in the hospital, and three isolates (isolates 3, 4, and 5) from July to September 2013 were found to have the same ST, PFGE pattern and rep-PCR group, indicating the same resistance clone.Admission to intensive care unit (ICU), peripheral vascular disease, males, hypoalbuminaemia, enema and linezolid therapy were identified as significant risk factors for LRE infections.Among these factors, admission to ICU, enema and linezolid therapy were independent risk factors for the acquisition of LRE.Conclusions Thirteen LRE isolates collected in the hospital showed a multidrug-resistant phenotype, and a small-scale prevalence was detected from 2011 to 2013.Therefore, attention should be paid to monitor the LRE in the hospital to decrease the prevalence of LRE infections.