Risk factors and outcome of levofloxacin-resistant Elizabethkingia meningoseptica bacteraemia in adult patients in Taiwan

Elizabethkingia meningoseptica is an emerging nosocomial pathogen associated with high mortality and inherently resistant to many antimicrobial agents. Levofloxacin has been considered as a therapeutic agent based on in vitro susceptibility. We aim to investigate the risk factors and outcomes for levofloxacin-resistant E. meningoseptica bacteraemia. Adult patients with E. meningoseptica bacteraemia were identified retrospectively in a medical centre in Taiwan from January 2011 to July 2015. These strains were identified by the Vitek2 automated system or matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. We compared clinical features and outcomes of patients with levofloxacin-resistant (MIC >2 μg/mL) and levofloxacin-susceptible (MIC ≤2 μg/mL) E. meningoseptica bacteraemia. A total of 93 patients were identified, including 51 (54.8%) with levofloxacin-resistant E. meningoseptica bacteraemia. The APACHE II score (OR, 1.08; 95% CI, 1.02–1.14; p = 0.008) was the only independent risk factor for levofloxacin-resistant E. meningoseptica bacteraemia. The 14-day mortality for patients with levofloxacin-resistant E. meningoseptica bacteraemia (attributable mortality: 30.7%) was significantly higher than that for patients with the levofloxacin-susceptible strain (56.9% versus 26.2%, p = 0.003). In the multivariate analysis of risk factors for mortality, appropriate definite antibiotic use was the only factor associated with 14-day survival (OR, 0.11; 95% CI, 0.02–0.55, p = 0.007). The levofloxacin-resistant strain was borderline significantly associated with mortality (OR, 3.09; 95% CI, 0.88–10.91, p = 0.079). The early identification of levofloxacin resistance in E. meningoseptica isolates is important to tackle this multi-drug resistance pathogen.