First identification of a multidrug-resistant Pseudomonas kurunegalensis clinical isolate co-carrying blaAFM-1 and blaIMP-1 in China.

OBJECTIVES

The objective of this study was to elucidate the genetic context and characterize chromosome co-carrying blaAFM-1 and blaIMP-1 in a multidrug-resistant Pseudomonas kurunegalensis (P. kurunegalensis) isolate obtained from human urine using whole-genome sequencing.

METHODS

This P. kurunegalensis isolate JC172 co-harbouring blaAFM-1 and blaIMP-1 underwent a comprehensive investigation that included antimicrobial susceptibility testing, conjugation assays, whole-genome sequencing and bioinformatic analyses. To depict the evolutionary dynamics of P. kurunegalensis strains on a global scale, a phylogenetic tree was generated based on single nucleotide polymorphisms of core genomes.

RESULTS

JC172 was classified as P. kurunegalensis based on sequencing results and average nucleotide identity (ANI) assessments. This isolate was designated as ST114 and possesses a chromosome with 5 855 340 base pairs, exhibiting a GC content of 61.9%. Several resistance genes, including blaAFM-1 and blaIMP-1, blaOXA-246 and tmexC3D2-toprJ1 were identified on the chromosome. Genomic analysis revealed that blaAFM-1 was situated within a core module of the TnAs3-blaAFM-1 unit, which is bordered by class 1 integrons. This arrangement implies a significant potential for blaAFM-1 dissemination.

CONCLUSIONS

Our study revealed that blaAFM-1 and blaIMP-1, blaOXA-246 and tmexC3D2-toprJ1 were harboured by P. kurunegalensis. We suggested that ST114 P. kurunegalensis may serve as a reservoir for resistance genes.