title: Regulation of the Klebsiella pneumoniae Kpc fimbriae by the site-specific recombinase KpcI.
abstract: In the genome of Klebsiella pneumoniae NTUH-K2044, nine fimbrial gene clusters were identified. Besides type 1 and type 3 fimbriae, the others are novel and were named Kpa, Kpb, Kpc, Kpd, Kpe, Kpf and Kpg fimbriae. Prevalence analysis among 105 K. pneumoniae clinical isolates revealed that the kpc genes were highly associated with the K1 serotype isolates. Induced expression of the recombinant kpcABCD genes in Escherichia coli resulted in Kpc fimbriation and increased biofilm formation. A putative site-specific recombinase encoding gene kpcI and a 302 bp intergenic DNA flanked by 11 bp inverted repeats, namely kpcS, were identified in the upstream region of the kpcABCD genes. Using LacZ as the reporter, a dramatic difference in promoter activity of kpcS in two different orientations was observed and accordingly assigned as ON and OFF phase. kpcI expression was found to be able to invert kpcS in trans from phase ON to OFF and vice versa. Using the two-plasmid system, expression of kpcA, encoding the major component of the Kpc fimbriae, could be observed upon the induced expression of kpcI. These results indicate that KpcI is involved in the regulation of Kpc fimbriation in a phase-variable manner.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsin Chu, Taiwan, ROC.
authors.forename: Chien-Chen
authors.initials: CC
authors.lastname: Wu
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsin Chu, Taiwan, ROC.
authors.forename: Ying-Jung
authors.initials: YJ
authors.lastname: Huang
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC.|Division of Infectious Diseases, Department of Internal Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Chang-Phone
authors.initials: CP
authors.lastname: Fung
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsin Chu, Taiwan, ROC.
authors.forename: Hwei-Ling
authors.initials: HL
authors.lastname: Peng
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D045522:Recombinases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D045522:Recombinases