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IMP-38-Producing High-Risk Sequence Type 307 Klebsiella pneumoniae Strains from a Neonatal Unit in China
Siyi Wang1, Juan Zhao1, Ning Liu1
1Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha, China.
Abstract:
An emerging multidrug-resistant Klebsiella pneumoniae high-risk clone of sequence type 307 (ST307) has been increasingly reported worldwide. Here, we described the genomic characteristics of an IMP-38-producing ST307 K. pneumoniae strain and investigated the prevalence of blaIMP-38 among carbapenem-resistant Klebsiella pneumoniae isolates from a tertiary care hospital in central China. A total of 14 IMP-38-producing ST307 K. pneumoniae strains were identified from 2013 to 2016, with 13 strains isolated from patients with neonatal sepsis in the neonatal ward. PacBio and Illumina whole-genome sequencing analysis performed on a representative IMP-38-producing K. pneumoniae strain, WCGKP294, showed that it contained a circular chromosome and two plasmids. Carbapenemase gene blaIMP-38 is colocated with blaCTX-M-3 in transposon Tn6382 on an IncHI5 plasmid (pWCGKP294-2). WCGKP294 harbors another IncFIB plasmid, pWCGKP294-1, carrying three copies of tandem-repeated IS26-blaSHV-2A-deoR-ygbJ-ygbK-fucA-IS26 composite transposon elements. Phylogenetic analysis placed WCGKP294 in the global ST307 cluster, distant from the U.S. (Texas) and South Africa clusters. Nevertheless, WCGKP294 does not contain the chromosomal fluoroquinolone resistance-associated mutations and IncFIIK/IncFIBK plasmid-associated blaCTX-M-15 gene that are frequently found in other global ST307 strains.IMPORTANCE We described the genome and resistome characterization of a carbapenem-resistant Klebsiella pneumoniae ST307 strain carrying blaIMP-38 in China. This report highlights that the high-risk ST307 clone continues to acquire different antimicrobial resistance genes, posing significant challenges to clinical practice, and should be closely monitored.
Insights
A multidrug-resistant Klebsiella pneumoniae ST307 clone carrying the IMP-38 carbapenemase gene was identified in China, primarily in neonatal sepsis patients. This highlights the evolving antimicrobial resistance of this high-risk bacterial strain.
Area of Science:
- Clinical Microbiology and Infectious Diseases
- Genomics and Molecular Epidemiology
- Antimicrobial Resistance Research
Background:
- Emergence of multidrug-resistant Klebsiella pneumoniae sequence type 307 (ST307) clone globally.
- Increasing reports of ST307 strains associated with severe infections.
- Need to understand genomic features and resistance mechanisms of emerging clones.
Purpose of the Study:
- To characterize the genomic features of an IMP-38-producing ST307 Klebsiella pneumoniae strain from China.
- To investigate the prevalence of the bla_IMP-38 gene among carbapenem-resistant Klebsiella pneumoniae isolates.
- To understand the genetic context and plasmid-mediated resistance in this high-risk clone.
Main Methods:
- Whole-genome sequencing (PacBio and Illumina) of a representative IMP-38-producing ST307 Klebsiella pneumoniae strain (WCGKP294).
- Identification and characterization of antimicrobial resistance genes and mobile genetic elements.
- Phylogenetic analysis to determine the global relatedness of the Chinese ST307 cluster.
Main Results:
- Fourteen IMP-38-producing ST307 Klebsiella pneumoniae strains were identified between 2013-2016, with 13 from neonatal sepsis patients.
- The bla_IMP-38 gene was found on an IncHI5 plasmid, co-located with bla_CTX-M-3 within transposon Tn6382.
- The sequenced strain WCGKP294 belonged to the global ST307 cluster but lacked common fluoroquinolone resistance mutations and bla_CTX-M-15 found in other ST307 strains.
Conclusions:
- The study characterizes a carbapenem-resistant Klebsiella pneumoniae ST307 strain carrying bla_IMP-38 in China.
- This highlights the adaptability of the ST307 clone in acquiring diverse antimicrobial resistance genes.
- Close monitoring of this high-risk clone is crucial due to its significant clinical implications.
