Molecular Characterization of a KPC-2- and NDM-1-Producing Clinical Isolate in Cerebrospinal Fluid.

OBJECTIVE

is an emerging pathogen. In this context, we characterised a strain fxq isolated from a cerebrospinal fluid specimen of a patient with tentorial meningioma, and the isolate produced carbapenemases of KPC and NDM types.

METHODS

The Phoenix 100 Automated Microbiology System, MALDI-TOF and whole-genome sequencing were used to identify the species. Anti-microbial susceptibility testing was also conducted with the Phoenix 100. The plasmid locations of the and genes were determined by S1-nuclease pulsed-field gel electrophoresis and Southern blot. The transfer capacity of plasmids carrying and was investigated by conjugation experiments, and the resistance plasmid stability was evaluated by culture and subculture. subtypes were identified by multi-locus sequence typing. We performed whole-genome sequencing to confirm species, characterise plasmids and analyse core genes.

RESULTS

fxq was originally identified as and showed resistance to imipenem and meropenem, but whole-genome sequencing identified it to be . The strain fxq belonged to the novel sequence type 202 (ST202) and carried the and genes located on the pB_KPC InFIA and pE_NDM IncU plasmids, respectively. The -carrying plasmid was successfully transferred to EC600 by conjugation, whereas the gene on the pE_NDM plasmid was not. The pB_KPC and pE_NDM plasmids demonstrated high stability.

CONCLUSION

This work is the first report on a carbapenem-resistant clinical isolate ST202 harbouring the and genes encoded by the IncFIA and IncU plasmids, respectively.