AUTHOR=Yan Rushuang , Lu Ye , Zhu Yiwei , Lan Peng , Jiang Shengnan , Lu Jun , Shen Ping , Yu Yunsong , Zhou Jiancang , Jiang Yan 

TITLE=A Sequence Type 23 Hypervirulent Klebsiella pneumoniae Strain Presenting Carbapenem Resistance by Acquiring an IncP1 blaKPC-2 Plasmid

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2021.641830

DOI=10.3389/fcimb.2021.641830

ISSN=2235-2988

ABSTRACT=<p>Hypervirulent <italic>Klebsiella pneumoniae</italic> strains are typically associated with severe infections and susceptible to most antimicrobial agents. In 2017, a carbapenem-resistant hypervirulent <italic>K. pneumoniae</italic> (CR-hvKP) strain was isolated from the sputum of a chronic obstructive pulmonary disease (COPD) patient in Zhejiang, China. The goal of the present study was to characterize the molecular features of the CR-hvKP isolate ZJ27003 and its <italic>bla</italic><sub>KPC-2</sub>-harboring plasmid p27003_KPC. Antimicrobial susceptibility was evaluated using the broth microdilution and agar dilution methods. String tests, serum-killing and mouse survival assays were performed to assess virulence, and plasmid conjugation was performed by filter mating. The complete genome sequence of ZJ27003 was acquired using a hybrid assembly of Illumina and Nanopore platform data. The sequence type (ST) of this CR-hvKP isolate was identified as ST23, which exhibits hypervirulence with high serum resistance and murine infection model. The strain is also resistant to carbapenems (imipenem, meropenem and ertapenem), aztreonam and cephalosporins. Additionally, the CR-hvKP isolate carries a 36,708-bp <italic>bla</italic><sub>KPC-2</sub>-harboring plasmid, named p27003_KPC, belonging to the P1 incompatibility (Inc) group. The backbone of p27003_KPC is similar to that of a <italic>bla</italic><sub>GES-5</sub>-harboring <italic>Pseudomonas aeruginosa</italic> plasmid, in which the <italic>bla</italic><sub>GES-5</sub> and its surrounding regions were replaced by a <italic>bla</italic><sub>KPC-2</sub>-containing translocatable unit derived from <italic>Enterobacteriaceae</italic>. The results of a conjugation assay revealed that p27003_KPC can be transferred from <italic>K. pneumoniae</italic> to <italic>P. aeruginosa</italic> PAO1 and make the recipient resistant against carbapenem. The identification of a carbapenem-resistant hypervirulent <italic>K. pneumoniae</italic> isolate carrying and disseminating the <italic>bla</italic><sub>KPC-2</sub> gene highlights a severe threat to public health.</p>