The Study Of RcsAB On Hypermucoviscosity And Biofilm In Klebsiella Pneumoniae

Objective To study the effect of RcsAB on hypermucoviscosity and biofilm formation ability of Klebsiella pneumonia by constructing unmarked rcsA-deletion, rcsB-deletion and, rcsAB-deletion mutants and their complementation strainsMethods First, unmarked rcs A-deletion, rcsB-deletion and rcsAB-deletion mutants were constructed. The upstream and downstream flanking DNA fragments of rcsA or rcsB were amplified by PCR and then cloned into the plasmid pKO3-Km. The recombinant plasmids were transformed into Klebsiella pneumoniae NTUH-K2044. After homologous recombination, unmarked rcsA-deletion, rcsB-deletion and, rcsAB-deletion mutants were screened. Second, complementation strains were constructed. The rcsA or rcsB fragment was amplified and cloned into the plasmid pBAD33, and then the recombinant plasmid was transformed into rcsA-deletion, rcsB-deletion or rcsAB-deletion mutant to get the complementation strains. The phenotypes of hypermucoviscosity and biofilm formation were tested.Results Unmarked rcsA-deletion, rcsB-deletion and rcsAB-deletion mutants and their complementation strains were constructed successfully. The results showed that the hypermucoviscosity and biofilm formation ability of mutants were decreased.Conclusions The transcription factor Rcs AB may positively regulate the hypermucoviscosity and biofilm formation ability of Klebsiella pneumonia.