Cloning and characterization of the gene cluster encoding type 3 (MR/K) fimbriae of Klebsiella pneumoniae

Abstract The gene cluster encoding the type 3 fimbriae of a Klebsiella pneumoniae isolate was cloned using the cosmid-cloning technique. Escherichia coli transformants, expressing type 3 fimbriae, were selected by reactivity with a monoclonal antibody directed against an epitope of the purified type 3 fimbriae. The phenotypic expression of type 3 fimbriae by transformants possessing the parental plasmid was dependent upon the host strain used. However, subcloning of this plasmid resulted in the construction of a chimeric molecule which imparted a stable phenotype regardless of the host strain. In addition, subcloning of the parental recombinant plasmid suggested that the minimal size of DNA necessary for production and expression of fimbriae was approximately 5.5 kb.