Characterisation of bla and bla co-occurrence in K64-ST11 carbapenem-resistant Klebsiella pneumoniae.

OBJECTIVES

The aim of this study was to characterise the co-occurrence of bla and bla in a K64-ST11 carbapenem-resistant Klebsiella pneumoniae strain.

METHODS

Antimicrobial susceptibility was determined by the disk diffusion method. Whole-genome sequencing was performed using Illumina MiSeq and PacBio II sequencers. High-quality reads were de novo assembled using the SOAPdenovo package. Genome annotation was performed using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP), and genome characteristics were analysed using bioinformatics methods.

RESULTS

Klebsiella pneumoniae strain KPWX136 was resistant to most of the tested antibiotics, being susceptible only to polymyxin B and tigecycline. The genome of strain KPWX136 is composed of a single chromosome (5 473 976 bp) and six plasmids including pA (191 359 bp), pB (134 972 bp), pC (117 844 bp), pD (87 095 bp), pE (11 970 bp) and pF (5596 bp). Complete sequence analysis revealed the resistome of isolate KPWX136, which included bla and bla together with 23 other resistance genes, of which 6 resistance genes were located on the chromosome and 19 on plasmids. Virulome analysis showed that KPWX136 carried a large number of virulence-associated genes. Meanwhile, 26 genomic islands and 6 prophages were predicted within the genome.

CONCLUSION

Genetic characterisation of K. pneumoniae KPWX136 co-harbouring bla and bla showed that it carried not only 25 resistance genes and a large number virulence factors but also various mobile genetic elements (MGEs) such as plasmids and genomic islands. Therefore, we must be alert to the transmission of resistance genes and virulence determinants via MGEs.