title: Fimbriae have distinguishable roles in Proteus mirabilis biofilm formation.
abstract: Proteus mirabilis is one of the most common etiological agents of complicated urinary tract infections, especially those associated with catheterization. This is related to the ability of P. mirabilis to form biofilms on different surfaces. This pathogen encodes 17 putative fimbrial operons, the highest number found in any sequenced bacterial species so far. The present study analyzed the role of four P. mirabilis fimbriae (MR/P, UCA, ATF and PMF) in biofilm formation using isogenic mutants. Experimental approaches included migration over catheter, swimming and swarming motility, the semiquantitative assay based on adhesion and crystal violet staining, and biofilm development by immunofluorescence and confocal microscopy. Different assays were performed using LB or artificial urine. Results indicated that the different fimbriae contribute to the formation of a stable and functional biofilm. Fimbriae revealed particular associated roles. First, all the mutants showed a significantly reduced ability to migrate across urinary catheter sections but neither swimming nor swarming motility were affected. However, some mutants formed smaller biofilms compared with the wild type (MRP and ATF) while others formed significantly larger biofilms (UCA and PMF) showing different bioarchitecture features. It can be concluded that P. mirabilis fimbriae have distinguishable roles in the generation of biofilms, particularly in association with catheters.
authors.affiliation: Department of Microbiology, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay.
authors.forename: Paola
authors.initials: P
authors.lastname: Scavone
authors.affiliation: Department of Microbiology, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay.
authors.forename: Victoria
authors.initials: V
authors.lastname: Iribarnegaray
authors.affiliation: Department of Microbiology, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay.
authors.forename: Ana Laura
authors.initials: AL
authors.lastname: Caetano
authors.affiliation: Department of Microbiology, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Schlapp
authors.affiliation: Laboratory for Scientific Image Processing (SCIAN-Lab), Biomedical Neuroscience Institute, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile.
authors.forename: Steffen
authors.initials: S
authors.lastname: Härtel
authors.affiliation: Department of Microbiology, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay pzunino@iibce.edu.uy.
authors.forename: Pablo
authors.initials: P
authors.lastname: Zunino
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D003470:Culture Media; D010861:Fimbriae, Bacterial / Q000502:physiology*; D006801:Humans; D011512:Proteus Infections / Q000382:microbiology; D011513:Proteus mirabilis / Q000502:physiology*; D062885:Urinary Catheters / Q000382:microbiology
chemical_list: D003470:Culture Media
keywords: Proteus mirabilis; biofilm; fimbriae; urinary tract infection