Background: During June-July 2012, six imipenem-resistant Escherichia coli isolates were isolated from two patients hospitalized in a ward of one large tertiary-care hospital in Genoa, Italy. Genetic features associated with blaNDM-4 gene were investigated.
Results: The isolates exhibited the same PFGE profile and a multidrug-resistant (MDR) phenotype to aminoglycosides, fluoroquinolones, and β-lactams. The strains produced the NDM-4 carbapenemase and the blaNDM-4 gene was part of the variable region of a class 1 integron. MLST analysis revealed that all isolates belonged to sequence type 405 (ST405).
Conclusions: This is the first report on the emergence of an MDR strain of E.coli producing the NDM-4 MBL in Italy.