Identification and characterization of the genes encoding the type 3 and type 1 fimbrial adhesins of Klebsiella pneumoniae.

Strains of Klebsiella pneumoniae are known to express two morphologically and functionally distinct filaments, the type 3 and the type 1 fimbriae. The gene (mrkD) encoding the adhesion of K. pneumoniae type 3 fimbriae was identified by transcomplementation analysis with the pap fimbrial gene cluster of Escherichia coli. The nucleotide sequence of the mrkD gene was determined. In addition, the determinant coding for the K. pneumoniae type 1 fimbrial adhesion was identified, and its nucleotide sequence was deduced. The predicted amino acid sequences of the K. pneumoniae adhesion proteins are compared, and similarities with the major fimbrial structural proteins (MrkA and FimA) are discussed.