AUTHOR=Zhang Na , Liu Xiong , Qi Lihua , Chen Jiali , Qin Shiyu , Jin Meiling , Yang Xiaojing , Liu Fangni , Guo Jinpeng , Liu Jie , Wang Changjun , Chen Yong 

TITLE=A clinical KPC-producing Klebsiella michiganensis strain carrying IncFII/IncFIA (HI1)/IncFIB (K) multiple replicon plasmid

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1086296

DOI=10.3389/fmicb.2022.1086296

ISSN=1664-302X

ABSTRACT=<p><italic>Klebsiella michiganensis</italic> is an increasingly important bacterial pathogen causing nosocomial infections in clinical patients. In this study, we described the molecular and genomic characteristics of a carbapenem-resistant <italic>K. michiganensis</italic> strain KM166 cultured from a one-month premature baby’s blood sample. KM166 showed lower biofilm forming ability in optical density (OD) than <italic>K. pneumoniae</italic> NTUH-K2044 (0.271 ± 0.027 vs. 0.595 ± 0.054, <italic>p</italic> = 0.001), and the median lethal dose (0.684 lg CFU/mL) was lower than <italic>K. pneumoniae</italic> strain NTUH-K2044 (6.679 lg CFU/mL). A IncFII/IncFIA(HI1)/IncFIB(K) multiple replicon plasmid in KM166 was identified carrying three replicon types. It has low homology to <italic>Escherichia coli</italic> pMRY09-581ECO_1 and the highest homology similarity to the INcFIA/INcFII(p14)-type plasmid in <italic>K. michiganensis</italic> strain fxq plasmid pB_KPC, suggesting that this multiple replicon plasmid was unlikely to have been transmitted from <italic>E. coli</italic> and probably a transfer of <italic>repFIB</italic> replicon genes from other <italic>K. michiganensis</italic> strains into the INcFIA/INcFII(p14)-type plasmid of KM166 had occurred. Mapping of the gene environment revealed that <italic>bla</italic><sub>KPC-2</sub> in KM166 plasmid 3 had high identity and same Tn3-tnpR-IS481-<italic>bla</italic><sub>KPC-2</sub>-klcA_1 genomic context structure with <italic>K. pneumoniae</italic> strain JKP55, plasmid pKPC-J5501, and <italic>bla</italic><sub>KPC-2</sub>-carrying plasmid proved to be autonomously transferred under the help of mobile genetic elements into <italic>Escherichia coli</italic> 600 by plasmid conjugation experiment. In conclusion, we have characterized a <italic>K. michiganensis</italic> strain carrying multi-replicon IncFII/IncFIA(HI1)/IncFIB(K) plasmid and <italic>bla</italic><sub>KPC-2</sub>-carrying IncFII(p14)/IncFIA plasmid in this study, which provided insights about the evolutionary diversity of plasmids carried by <italic>K. michiganensis</italic>.</p>