Demonstration of regulatory cross-talk between P fimbriae and type 1 fimbriae in uropathogenic Escherichia coli.
The majority of Escherichia coli strains isolated from urinary tract infections have the potential to express multiple fimbriae. Two of the most common fimbrial adhesins are type 1 fimbriae and pyelonephritis-associated pili (Pap). Previous research has shown that induced, plasmid-based expression of a Pap regulator, papB, and its close homologues can prevent inversion of the fim switch controlling the expression of type 1 fimbriae. The aim of the present study was to determine if this cross-regulation occurs when PapB is expressed from its native promoter in the chromosome of E. coli K-12 and clinical isolates. The regulation was examined in three ways: (1) mutated alleles of the pap regulatory region, including papB and papI, that maintain the pap promoter in either the off or the on phase were exchanged into the chromosome of both E. coli K-12 and the clinical isolate E. coli CFT073, and the effect on type 1 fimbrial expression was measured; (2) type 1 fimbrial expression was determined using a novel fimS : : gfp(+) reporter system in mutants of the clinical isolate E. coli 536 in which combinations of complete fimbrial clusters had been deleted; (3) type 1 fimbrial expression was determined in a range of clinical isolates and compared with both the number of P clusters and their expression. All three approaches demonstrated that P expression represses type 1 fimbrial expression. Using a number of novel genetic approaches, this work extends the initial finding that PapB inhibits FimB recombination to the impact of this regulation in clinical isolates.
Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
Nicola J
NJ
Holden
Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
Makrina
M
Totsika
Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
Eva
E
Mahler
Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
Andrew J
AJ
Roe
Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
Kirsteen
K
Catherwood
Institute for Molecular Infection Biology, University of Würzburg, Röntgenring 11-97070 Würzburg, Germany.
Karin
K
Lindner
Institute for Molecular Infection Biology, University of Würzburg, Röntgenring 11-97070 Würzburg, Germany.
Ulrich
U
Dobrindt
Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
David L
DL
Gally
D018829:Adhesins, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D019677:Artificial Gene Fusion; D015139:Blotting, Southern; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000235:genetics*; D017353:Gene Deletion; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006384:Hemagglutination; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D009154:Mutation; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology
D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C086707:PapI protein, E coli; D012097:Repressor Proteins; D014157:Transcription Factors; C116245:atpD protein, E coli; D049452:Green Fluorescent Proteins; D015252:Deoxyribonucleases, Type II Site-Specific; C032229:GANTC-specific type II deoxyribonucleases