Ning Dong1,2, Dachuan Lin1,2, Rong Zhang3, Edward Wai-Chi Chan1,2, Sheng Chen1,2. 1. Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen Research Institute, Shenzhen, China. 2. State Key Lab of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. 3. Department of Clinical Laboratory Medicine, Second Affiliated Hospital of Zhejiang University, Hangzhou, China.
Abstract
Objectives: To characterize a plasmid in a K1 hypervirulent Klebsiella pneumoniae (HvKP) strain encoding both hypervirulence and carbapenem resistance phenotypes. Methods: Plasmids from HvKP strain KP70-2 were subjected to whole-plasmid sequencing using both the Illumina NextSeq 500 sequencing platform and Nanopore MinION sequencer platforms. Results: A hybrid virulence- and resistance-encoding plasmid of 240 kb, harbouring both the virulence gene rmpA2 and the carbapenemase gene blaKPC-2, was recovered from a clinical HvKP strain. Designated pKP70-2, the plasmid was found to be almost structurally identical to various known hypervirulence-encoding plasmids harboured by other HvKP strains, except for an extra MDR-encoding region located within the genetically conserved plasmid backbone. This MDR region was flanked by two copies of IS26 in the same orientation, one at each end and linked to an external 8 bp (CTAAAATT) product of target site duplications, suggesting that an insertion event was responsible for the integration of the MDR region into the virulence plasmid. The MDR region was also found to harbour mobile elements that in turn contain the antibiotic resistance genes dfrA14 and blaKPC-2. Conclusions: Based on the genetic composition of pKP70-2, we postulate that the multiple insertion elements that it harbours were responsible for mediating the plasmid recombination events that underlie continuous emergence and genetic adaptation of novel resistance- and virulence-encoding mobile elements in K. pneumoniae.
Objectives: To characterize a plasmid in a K1 hypervirulent Klebsiella pneumoniae (HvKP) strain encoding both hypervirulence and carbapenem resistance phenotypes. Methods: Plasmids from HvKP strain KP70-2 were subjected to whole-plasmid sequencing using both the Illumina NextSeq 500 sequencing platform and Nanopore MinION sequencer platforms. Results: A hybrid virulence- and resistance-encoding plasmid of 240 kb, harbouring both the virulence gene rmpA2 and the carbapenemase gene blaKPC-2, was recovered from a clinical HvKP strain. Designated pKP70-2, the plasmid was found to be almost structurally identical to various known hypervirulence-encoding plasmids harboured by other HvKP strains, except for an extra MDR-encoding region located within the genetically conserved plasmid backbone. This MDR region was flanked by two copies of IS26 in the same orientation, one at each end and linked to an external 8 bp (CTAAAATT) product of target site duplications, suggesting that an insertion event was responsible for the integration of the MDR region into the virulence plasmid. The MDR region was also found to harbour mobile elements that in turn contain the antibiotic resistance genes dfrA14 and blaKPC-2. Conclusions: Based on the genetic composition of pKP70-2, we postulate that the multiple insertion elements that it harbours were responsible for mediating the plasmid recombination events that underlie continuous emergence and genetic adaptation of novel resistance- and virulence-encoding mobile elements in K. pneumoniae.
Authors: Maria Karlsson; Richard A Stanton; Uzma Ansari; Gillian McAllister; Monica Y Chan; Erisa Sula; Julian E Grass; Nadezhda Duffy; Melissa L Anacker; Medora L Witwer; J Kamile Rasheed; Christopher A Elkins; Alison Laufer Halpin Journal: Antimicrob Agents Chemother Date: 2019-06-24 Impact factor: 5.191
Authors: Margaret M C Lam; Kelly L Wyres; Ryan R Wick; Louise M Judd; Aasmund Fostervold; Kathryn E Holt; Iren Høyland Löhr Journal: J Antimicrob Chemother Date: 2019-05-01 Impact factor: 5.790