Three separate acquisitions of bla NDM-1 in three different bacterial species from a single patient

To investigate the acquisition and relatedness of New Delhi Metallo-beta-lactamase among multiple separate species from one patient. Five isolates from three species ( Pseudomonas aeruginosa ; Pa, Acinetobacter baumannii ; Ab and Proteus mirabilis ; Pm) suspected of harbouring a carbapenemase were investigated by phenotype (antimicrobial susceptibilities) and whole genome sequencing. Epidemiological data was collected on this patient. Three different carbapenemase genes were detected; bla VIM-1 ( Pa; ST773), bla OXA-23 ( Ab , ST499) and bla NDM-1 identified in all isolates. NDM regions were found chromosomally integrated in all isolates. Data showed no evidence of NDM-1 transfer within this patient suggesting the enzyme was acquired in three separate events.