Tedizolid for Treatment of Enterococcal Bacteremia

Background: Due to the high prevalence of vancomycin-resistant enterococci (VRE) and emergence of daptomycin-nonsusceptible enterococci (DNSE) in the US hospital settings, tedizolid provides an alternative choice for the treatment of serious infections caused by VRE and DNSE. We share our experience in treatment of enterococcal bacteremia with a focus on DNSE using tedizolid as salvage antibiotic therapy.

Methods: DNSE and VRE isolates were identified on the basis of colony morphology, conventional biochemical tests, and were confirmed by analysis of 16S rRNA gene sequence or by the MALDI Biobiotyper CA System (Bruker). DNSE was defined as an enterococci isolate with a daptomycin minimum inhibitory concentration (MIC) of >4 μg/ml as determined by MicroScan System (Siemens)) and confirmed by Etest (bioMérieux). In vitro susceptibility of tedizolid and linezolid for these isolates were performed by broth microdilution using the Sensititre™ panel (Thermo Fisher Scientific) in accordance with the guidelines of the Clinical and Laboratory Standards Institute (CLSI).

Results: 4 patients with E. faecium bacteremia were treated with tedizolid 200 mg once a day in a medical center in suburban New York City from November 2014 through June 2015. Tedizolid was used as salvage therapy in these patients who had multiple contraindications for treatment with other antibiotics based on susceptibility data, existing laboratory abnormalities and potential drug interactions.

Case	Patient Characteristics	Indication of treatment	DAP MIC μg/ml	LIN MIC μg/ml	TED MIC μg/ml	Duration of Treatment (Days)	Outcome
1	60/M renal transplantation	VRE bacteremia Rhabdomyolysis, thrombocytopenia	4	1	0.25	14	Cure
2	75/M Burkitt’s lymphoma	DNSE bacteremia	16	2	0.25	14	Cure
3	49/M Cirrhosis	DNSE bacteremia	6	2	0.25	10	Cure
4	54/F Acute Leukemia	DNSE bacteremia	32	2	0.25	7	Cure

Conclusion: Our clinical data confirms the microbiological and pharmacological basis for potential use of tedizolid as salvage therapy in patients with infections caused by daptomycin-nonsusceptible enterococci.