title: Spatiotemporal distribution of different extracellular polymeric substances and filamentation mediate Xylella fastidiosa adhesion and biofilm formation.
abstract: Microorganism pathogenicity strongly relies on the generation of multicellular assemblies, called biofilms. Understanding their organization can unveil vulnerabilities leading to potential treatments; spatially and temporally-resolved comprehensive experimental characterization can provide new details of biofilm formation, and possibly new targets for disease control. Here, biofilm formation of economically important phytopathogen Xylella fastidiosa was analyzed at single-cell resolution using nanometer-resolution spectro-microscopy techniques, addressing the role of different types of extracellular polymeric substances (EPS) at each stage of the entire bacterial life cycle. Single cell adhesion is caused by unspecific electrostatic interactions through proteins at the cell polar region, where EPS accumulation is required for more firmly-attached, irreversibly adhered cells. Subsequently, bacteria form clusters, which are embedded in secreted loosely-bound EPS, and bridged by up to ten-fold elongated cells that form the biofilm framework. During biofilm maturation, soluble EPS forms a filamentous matrix that facilitates cell adhesion and provides mechanical support, while the biofilm keeps anchored by few cells. This floating architecture maximizes nutrient distribution while allowing detachment upon larger shear stresses; it thus complies with biological requirements of the bacteria life cycle. Using new approaches, our findings provide insights regarding different aspects of the adhesion process of X. fastidiosa and biofilm formation.
authors.affiliation: Applied Physics Department, Institute of Physics 'Gleb Wataghin', State University of Campinas, 13083-859, Campinas, São Paulo, Brazil.
authors.forename: Richard
authors.initials: R
authors.lastname: Janissen
authors.affiliation: Applied Physics Department, Institute of Physics 'Gleb Wataghin', State University of Campinas, 13083-859, Campinas, São Paulo, Brazil.
authors.forename: Duber M
authors.initials: DM
authors.lastname: Murillo
authors.affiliation: Citrus Center APTA 'Sylvio Moreira', Agronomic Institute of Campinas, 13490-970, Cordeirópolis, São Paulo, Brazil.
authors.forename: Barbara
authors.initials: B
authors.lastname: Niza
authors.affiliation: Applied Physics Department, Institute of Physics 'Gleb Wataghin', State University of Campinas, 13083-859, Campinas, São Paulo, Brazil.
authors.forename: Prasana K
authors.initials: PK
authors.lastname: Sahoo
authors.affiliation: Fundamental Chemistry Department, Institute of Chemistry, University of São Paulo, 05508-000, São Paulo, Brazil.
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Nobrega
authors.affiliation: Quantum Electronics Department, Institute of Physics 'Gleb Wataghin', State University of Campinas, 13083-859, Campinas, São Paulo, Brazil.
authors.forename: Carlos L
authors.initials: CL
authors.lastname: Cesar
authors.affiliation: Fundamental Chemistry Department, Institute of Chemistry, University of São Paulo, 05508-000, São Paulo, Brazil.
authors.forename: Marcia L A
authors.initials: ML
authors.lastname: Temperini
authors.affiliation: Structural and Functional Biology Department, Institute of Biology, State University of Campinas, 13083-865, Campinas, São Paulo, Brazil.
authors.forename: Hernandes F
authors.initials: HF
authors.lastname: Carvalho
authors.affiliation: Citrus Center APTA 'Sylvio Moreira', Agronomic Institute of Campinas, 13490-970, Cordeirópolis, São Paulo, Brazil.
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: de Souza
authors.affiliation: Applied Physics Department, Institute of Physics 'Gleb Wataghin', State University of Campinas, 13083-859, Campinas, São Paulo, Brazil.
authors.forename: Monica A
authors.initials: MA
authors.lastname: Cotta
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D004269:DNA, Bacterial / Q000737:chemistry; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D044167:Xylella / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D004269:DNA, Bacterial