An efficient method for knocking out genes on the virulence plasmid of hypervirulent Klebsiella pneumoniae.

Currently, the infection of hypervirulent Klebsiella pneumoniae (hvKp) is becoming increasingly serious and the virulent mechanisms of hvKp are still not very clear. An effective gene-editing method for genes on hvKp virulence plasmid can help us reveal related virulent mechanisms. There are a few reports focusing on the methods mentioned above, however with certain limitations. In this work, we first constructed the pRE112-basing recombinant suicide plasmid to knock out or replace the genes in the hvKp virulence plasmid based on the principle of homology recombination. Results showed that the target virulent genes iucA, iucB, iroB, and rmpA2 on the hvKp virulence plasmid were scarlessly knocked out or replaced by marker genes, and mutant hvKp strains with the expected phenotypes were obtained. These indicated that we established an efficient gene-editing method for genes on hvKp virulence plasmid, which could help us explore the functions of these genes and reveal the virulent mechanisms of hvKp.