Clinical Characteristics and Low Susceptibility to Daptomycin in Enterococcus faecium Bacteremia

Clinical Characteristics and Low Susceptibility to Daptomycin in Enterococcus faecium Bacteremia

HIROKI NAMIKAWA,^1,2 KOICHI YAMADA,^1,4 WATARU SHIBATA,^1,4 HIROKI FUJIMOTO,^1,4 ETSUKO TAKIZAWA,⁴ MAKOTO NIKI,⁴ KIYOTAKA NAKAIE,1, 4 YASUTAKA NAKAMURA,⁴ KEN-ICHI OINUMA,³ MAMIKO NIKI,³ YASUHIKO TAKEMOTO,² YUKIHIRO KANEKO,³ TAICHI SHUTO² and HIROSHI KAKEYA^1,4

¹Department of Infection Control Science, Osaka City University, Graduate School of Medicine, Osaka, Osaka, Japan
²Department of Medical Education and General Practice, Osaka City University, Graduate School of Medicine, Osaka, Osaka, Japan
³Department of Bacteriology, Osaka City University, Graduate School of Medicine, Osaka, Osaka, Japan
⁴Department of Infection Control and Prevention, Osaka City University Hospital, Osaka, Osaka, Japan

Enterococcus faecium has high levels of resistance to multiple antibiotics, and the mortality due to E. faecium bacteremia is high. Accordingly, E. faecium strains with low susceptibility to daptomycin are a concern in clinical practice. This study assessed the predictive factors and prognosis of patients with bacteremia due to E. faecium as well as the antimicrobial susceptibility, particularly to daptomycin, among E. faecium isolates. The medical records of patients admitted to Osaka City University Hospital with E. faecalis (n = 60) and E. faecium (n = 48) bacteremia between January 2011 and March 2016 were retrospectively reviewed. The E. faecalis group (mean age: 62.0 years) included 22 women, and the E. faecium group (mean age: 59.1 years) included 19 women. Predictive factors for infection, prognosis, and isolate antimicrobial susceptibilities were evaluated. The mean Sequential Organ Failure Assessment score and mortality rate did not differ between the two groups. The independent predictors of E. faecium bacteremia in multivariate analysis included quinolone use (p = 0.025), malignancy (p = 0.021), and prolonged hospitalization (p = 0.016). Cardiovascular disease was associated with a reduced risk of E. faecium bacteremia (p = 0.015). Notably, the percentage of E. faecium isolates with low daptomycin susceptibility was higher than that of E. faecalis (8.5% vs. 0%, p = 0.036). Thus, E. faecium should be considered when administering antibiotic therapy to patients with a history of these predictors. Furthermore, the use of daptomycin should be avoided in case of E. faecium with low susceptibility to daptomycin.

keywords —— bacteremia; daptomycin; Enterococcus faecalis; Enterococcus faecium; low susceptibility

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Tohoku J. Exp. Med., 2017, 243, 211-218

Correspondence: Hiroshi Kakeya, M.D., Ph.D., Department of Infection Control Science, Osaka City University, Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, Osaka 545-8585, Japan.

e-mail: kakeya@med.osaka-cu.ac.jp