IMP-38-Producing High-Risk Sequence Type 307 Klebsiella pneumoniae Strains from a Neonatal Unit in China

Abstract

We described the genome and resistome characterization of a carbapenem-resistant Klebsiella pneumoniae ST307 strain carrying bla IMP-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. 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 bla IMP-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 bla IMP-38 is colocated with bla CTX-M-3 in transposon Tn 6382 on an IncHI5 plasmid (pWCGKP294-2). WCGKP294 harbors another IncFIB plasmid, pWCGKP294-1, carrying three copies of tandem-repeated IS 26 - bla SHV-2A - deoR - ygbJ - ygbK - fucA -IS 26 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 bla CTX-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 bla IMP-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.