title: Characterization of biofilm formation by Borrelia burgdorferi in vitro.
abstract: Borrelia burgdorferi, the causative agent of Lyme disease, has long been known to be capable of forming aggregates and colonies. It was recently demonstrated that Borrelia burgdorferi aggregate formation dramatically changes the in vitro response to hostile environments by this pathogen. In this study, we investigated the hypothesis that these aggregates are indeed biofilms, structures whose resistance to unfavorable conditions are well documented. We studied Borrelia burgdorferi for several known hallmark features of biofilm, including structural rearrangements in the aggregates, variations in development on various substrate matrices and secretion of a protective extracellular polymeric substance (EPS) matrix using several modes of microscopic, cell and molecular biology techniques. The atomic force microscopic results provided evidence that multilevel rearrangements take place at different stages of aggregate development, producing a complex, continuously rearranging structure. Our results also demonstrated that Borrelia burgdorferi is capable of developing aggregates on different abiotic and biotic substrates, and is also capable of forming floating aggregates. Analyzing the extracellular substance of the aggregates for potential exopolysaccharides revealed the existence of both sulfated and non-sulfated/carboxylated substrates, predominately composed of an alginate with calcium and extracellular DNA present. In summary, we have found substantial evidence that Borrelia burgdorferi is capable of forming biofilm in vitro. Biofilm formation by Borrelia species might play an important role in their survival in diverse environmental conditions by providing refuge to individual cells.
authors.affiliation: Lyme Disease Research Group, Department of Biology and Environmental Sciences, University of New Haven, West Haven, CT, USA. esapi@newhaven.edu
authors.forename: Eva
authors.initials: E
authors.lastname: Sapi
authors.forename: Scott L
authors.initials: SL
authors.lastname: Bastian
authors.forename: Cedric M
authors.initials: CM
authors.lastname: Mpoy
authors.forename: Shernea
authors.initials: S
authors.lastname: Scott
authors.forename: Amy
authors.initials: A
authors.lastname: Rattelle
authors.forename: Namrata
authors.initials: N
authors.lastname: Pabbati
authors.forename: Akhila
authors.initials: A
authors.lastname: Poruri
authors.forename: Divya
authors.initials: D
authors.lastname: Burugu
authors.forename: Priyanka A S
authors.initials: PA
authors.lastname: Theophilus
authors.forename: Truc V
authors.initials: TV
authors.lastname: Pham
authors.forename: Akshita
authors.initials: A
authors.lastname: Datar
authors.forename: Navroop K
authors.initials: NK
authors.lastname: Dhaliwal
authors.forename: Alan
authors.initials: A
authors.lastname: MacDonald
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Rossi
authors.forename: Saion K
authors.initials: SK
authors.lastname: Sinha
authors.forename: David F
authors.initials: DF
authors.lastname: Luecke
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D025065:Borrelia burgdorferi / Q000254:growth & development* / Q000378:metabolism; D018625:Microscopy, Atomic Force