Successful, but incomplete control of a Serratia marcescens blaIMP-4 outbreak related to contaminated hand basin waste-water systems

Background: Serratia marcescens is a common healthcare associated infection that is intrinsically resistant to colistin and is occasionally linked to environmental contamination. After the identification of a number of clinical (n=2) and faecal colonization (n=5) isolates of carbapenem-resistant S. marcescens producing blaIMP-4 (SM-IMP4), we investigated potential environmental reservoirs in our hospital.