biostudies-literatureUnknown13Zhang NBeijing Nova ProgramNational Natural Science Foundation of China<i>Klebsiella michiganensis</i> 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 <i>K. michiganensis</i> strain KM166 cultured from a one-month premature baby's blood sample. KM166 showed lower biofilm forming ability in optical density (OD) than <i>K. pneumoniae</i> NTUH-K2044 (0.271 ± 0.027 vs. 0.595 ± 0.054, <i>p</i> = 0.001), and the median lethal dose (0.684 lg CFU/mL) was lower than <i>K. pneumoniae</i> 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 <i>Escherichia coli</i> pMRY09-581ECO_1 and the highest homology similarity to the INcFIA/INcFII(p14)-type plasmid in <i>K. michiganensis</i> strain fxq plasmid pB_KPC, suggesting that this multiple replicon plasmid was unlikely to have been transmitted from <i>E. coli</i> and probably a transfer of <i>repFIB</i> replicon genes from other <i>K. michiganensis</i> strains into the INcFIA/INcFII(p14)-type plasmid of KM166 had occurred. Mapping of the gene environment revealed that <i>bla</i> _KPC-2 in KM166 plasmid 3 had high identity and same Tn3-tnpR-IS481-<i>bla</i> _KPC-2-klcA_1 genomic context structure with <i>K. pneumoniae</i> strain JKP55, plasmid pKPC-J5501, and <i>bla</i> _KPC-2-carrying plasmid proved to be autonomously transferred under the help of mobile genetic elements into <i>Escherichia coli</i> 600 by plasmid conjugation experiment. In conclusion, we have characterized a <i>K. michiganensis</i> strain carrying multi-replicon IncFII/IncFIA(HI1)/IncFIB(K) plasmid and <i>bla</i> _KPC-2-carrying IncFII(p14)/IncFIA plasmid in this study, which provided insights about the evolutionary diversity of plasmids carried by <i>K. michiganensis</i>.Frontiers in microbiology1086296https://www.ebi.ac.uk/biostudies/studies/S-EPMC9845883biostudies-literatureA clinical KPC-producing <i>Klebsiella michiganensis</i> strain carrying IncFII/IncFIA (HI1)/IncFIB (K) multiple replicon plasmid.PMC9845883Liu XYang XQi LLiu JGuo JChen JWang CJin MZhang NChen YLiu FQin SfalseA clinical KPC-producing <i>Klebsiella michiganensis</i> strain carrying IncFII/IncFIA (HI1)/IncFIB (K) multiple replicon plasmid.<i>Klebsiella michiganensis</i> 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 <i>K. michiganensis</i> strain KM166 cultured from a one-month premature baby's blood sample. KM166 showed lower biofilm forming ability in optical density (OD) than <i>K. pneumoniae</i> NTUH-K2044 (0.271 ± 0.027 vs. 0.595 ± 0.054, <i>p</i> = 0.001), and the median lethal dose (0.684 lg CFU/mL) was lower than <i>K. pneumoniae</i> 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 <i>Escherichia coli</i> pMRY09-581ECO_1 and the highest homology similarity to the INcFIA/INcFII(p14)-type plasmid in <i>K. michiganensis</i> strain fxq plasmid pB_KPC, suggesting that this multiple replicon plasmid was unlikely to have been transmitted from <i>E. coli</i> and probably a transfer of <i>repFIB</i> replicon genes from other <i>K. michiganensis</i> strains into the INcFIA/INcFII(p14)-type plasmid of KM166 had occurred. Mapping of the gene environment revealed that <i>bla</i> _KPC-2 in KM166 plasmid 3 had high identity and same Tn3-tnpR-IS481-<i>bla</i> _KPC-2-klcA_1 genomic context structure with <i>K. pneumoniae</i> strain JKP55, plasmid pKPC-J5501, and <i>bla</i> _KPC-2-carrying plasmid proved to be autonomously transferred under the help of mobile genetic elements into <i>Escherichia coli</i> 600 by plasmid conjugation experiment. In conclusion, we have characterized a <i>K. michiganensis</i> strain carrying multi-replicon IncFII/IncFIA(HI1)/IncFIB(K) plasmid and <i>bla</i> _KPC-2-carrying IncFII(p14)/IncFIA plasmid in this study, which provided insights about the evolutionary diversity of plasmids carried by <i>K. michiganensis</i>.2022-01-01T00:00:00Z20222026-05-09T03:10:55.384Z2025-02-19T02:38:41.799ZS-EPMC98458833668764210.3389/fmicb.2022.1086296