AUTHOR=Tian Chongmei , Xing Mengyu , Zhao Yaping , Fan Xueyu , Bai Yongfeng , Fu Liping , Wang Siwei 

TITLE=Whole genome sequencing of OXA-232-producing wzi93-KL112-O1 carbapenem-resistant Klebsiella pneumoniae in human bloodstream infection co-harboring chromosomal ISEcp1-based blaCTX-M-15 and one rmpA2-associated virulence plasmid

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.984479

DOI=10.3389/fcimb.2022.984479

ISSN=2235-2988

ABSTRACT=<sec><title>Objectives</title><p>To characterize one OXA-232-producing <italic>wzi93</italic>-KL112-O1 carbapenem-resistant <italic>Klebsiella pneumoniae</italic> (CRKP) co-harboring chromosomal <italic>bla</italic><sub>CTX-M-15</sub> and one <italic>rmpA2</italic>-associated virulence plasmid.</p></sec><sec><title>Methods</title><p>Minimum inhibitory concentrations (MICs) were measured <italic>via</italic> broth microdilution method. Conjugation, chemical transformation, string test and <italic>Galleria mellonella</italic> infection model experiments were also conducted. Whole-genome sequencing (WGS) was performed on the Illumina and Nanopore platforms. Antimicrobial resistance determinants were identified using ABRicate program with ResFinder database. Insertion sequences (ISs) were identified using ISfinder. Bacterial virulence factors were identified using virulence factor database (VFDB). Wzi, capsular polysaccharide (KL) and lipoolygosaccharide (OCL) were analyzed using Kleborate with <italic>Kaptive</italic>. Phylogenetic analysis of 109 ST15 <italic>K. pneumoniae</italic> strains was performed using core genome multilocus sequence typing (cgMLST) on the Ridom SeqSphere+ server. MLST, replicons type, SNP strategies and another cgMLST analysis for 45 OXA-232-producing <italic>K. pneumoniae</italic> strains were further conducted using BacWGSTdb server.</p></sec><sec><title>Results</title><p><italic>K. pneumoniae</italic> KPTCM strain belongs to ST15 with <italic>wzi93</italic>, KL112 and O1. It possessed a multidrug-resistant (MDR) profile and was resistant to carbapenems (meropenem and ertapenem), ciprofloxacin and amikacin. Virulence assays demonstrated KPTCM strain possesses a low virulence phenotype. WGS revealed it contained one circular chromosome and nine plasmids. The carbapenemase-encoding gene <italic>bla</italic><sub>OXA-232</sub> was located in a 6141-bp ColKP3-type non-conjugative plasmid and flanked by ΔIS<italic>Ecp1</italic> and Δ<italic>lysR</italic>-Δ<italic>ereA</italic>. Interestingly, <italic>bla</italic><sub>CTX-M-15</sub> was located in the chromosome mediated by IS<italic>Ecp1-</italic>based transposon Tn<italic>2012</italic>. Importantly, it harbored a <italic>rmpA2</italic>-associated pLVPK-like virulence plasmid with <italic>iutA</italic>-<italic>iucABCD</italic> gene cluster and one IS<italic>26</italic>-mediated MDR fusion plasmid according to 8-bp (AGCTGCAC or GGCCTTTG) target site duplications (TSD). Based on the cgMLST and SNP analysis, data showed OXA-232-producing ST15 <italic>K. pneumoniae</italic> isolates were mainly isolated from China and have evolved in recent years.</p></sec><sec><title>Conclusions</title><p>Early detection of CRKP strains carrying chromosomal <italic>bla</italic><sub>CTX-M-15</sub>, OXA-232 carbapenemase and pLVPK-like virulence plasmid is recommended to avoid the extensive spread of this high-risk clone.</p></sec>