Coexistence of NDM-1-producing Escherichia coli and Citrobacter freundii in the same patient

An NDM-1-encoding plasmid harboured by various clinical isolates in a single patient is worrying considering that this plasmid may be widespread in our hospital. Furthermore, the threat of carbapenemase-producing bacterial epidemics should be closely monitored. However, a limitation of this study was the extremely small sample size.