Characterization of daptomycin non-susceptible Enterococcus faecium producing urinary tract infection in a renal transplant recipient

Abstract

Objectives: Characterization of a urine isolate of daptomycin non-susceptible Enterococcus faecium recovered from a patient with kidney transplantation and no history of daptomycin exposure.

Methods: After isolation in a urine sample, identification of E. faecium was confirmed by amplification of the E. faecium-specific gene encoding D-alanyl-D-alanine ligase (ddl) and daptomycin susceptibility testing was performed by E-test on cation-adjusted Mueller-Hinton agar. In order to determine the genetic bases of daptomycin resistance, the open reading frames of five genes previously associated with daptomycin resistance in enterococci were sequenced.

Results: Substitutions in the response regulator LiaR (S19F) and cardiolipin synthase (R218Q) were identified.

Conclusions: To the best of our knowledge, this is the first characterization of emerging daptomycin resistance in E. faecium in a Spanish hospital in the absence of daptomycin exposure and in a renal transplant recipient.