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

Abstract

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.