title: Effect of RpoN, RpoS and LuxS Pathways on the Biofilm Formation and Antibiotic Sensitivity ofBorrelia Burgdorferi.
abstract: Borrelia burgdorferi, the causative agent of Lyme disease, is capable of forming biofilmin vivoandin vitro, a structure well known for its resistance to antimicrobial agents. For the formation of biofilm, signaling processes are required to communicate with the surrounding environment such as it was shown for the RpoN-RpoS alternative sigma factor and for the LuxS quorum-sensing pathways. Therefore, in this study, the wild-typeB. burgdorferiand different mutant strains lacking RpoN, RpoS, and LuxS genes were studied for their growth characteristic and development of biofilm structures and markers as well as for their antibiotic sensitivity. Our results showed that all three mutants formed small, loosely formed aggregates, which expressed previously identifiedBorreliabiofilm markers such as alginate, extracellular DNA, and calcium. All three mutants had significantly different sensitivity to doxycyline in the early log phase spirochete cultures; however, in the biofilm rich stationary cultures, only LuxS mutant showed increased sensitivity to doxycyline compared to the wild-type strain. Our findings indicate that all three mutants have some effect onBorreliabiofilm, but the most dramatic effect was found with LuxS mutant, suggesting that the quorum-sensing pathway plays an important role ofBorreliabiofilm formation and antibiotic sensitivity.
authors.affiliation: Department of Biology and Environmental Science, University of New Haven , West Haven, CT 06516, USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Sapi
authors.affiliation: Department of Biology and Environmental Science, University of New Haven , West Haven, CT 06516, USA.
authors.forename: Priyanka A S
authors.initials: PA
authors.lastname: Theophilus
authors.affiliation: Department of Biology and Environmental Science, University of New Haven , West Haven, CT 06516, USA.
authors.forename: Truc V
authors.initials: TV
authors.lastname: Pham
authors.affiliation: Department of Biology and Environmental Science, University of New Haven , West Haven, CT 06516, USA.
authors.forename: Divya
authors.initials: D
authors.lastname: Burugu
authors.affiliation: Department of Biology and Environmental Science, University of New Haven , West Haven, CT 06516, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Luecke
keywords: Lyme disease; alginate; biofilm; eDNA; mucopolysaccharides; quorum sensing; sigma factor