title: The mode of biofilm formation on smooth surfaces by Campylobacter jejuni.
abstract: Many microorganisms produce extracellular polymers referred to collectively as "slime" or glycocalyx, and form biofilms on solid surfaces in natural ecosystems. Campylobacter jejuni, one of the most important foodborne pathogens, also has the ability to form biofilm on stainless steel, glass, or polyvinyl chloride in vitro. However, the issue of biofilm formation by Campylobacter species has not been extensively examined. The present study was performed to examine the mode of adhesion of C. jejuni to a smooth surface. When bacterial suspensions in Brucella broth were incubated in microplate wells with a glass coverslip, microcolonies 0.5~2 mm in diameter were formed on the coverslip within 2 hr from the start of incubation. These microcolonies gradually grew and formed a biofilm of net-like connections within 6 hr. Transmission electron microscopy indicated that massive amounts of extracellular material masked the cell surface, and this material bound ruthenium red, suggesting the presence of a polysaccharide moiety. Scanning electron microscopy indicated that the flagella acted as bridges, forming net-like connections between the organisms. To determine the genes associated with biofilm formation, aflagellate (flaA(-)) and flagellate but non-motile (motA(-)) mutants were constructed from strain 81-176 by natural transformation-mediated allelic exchange. The flaA(-) and motA(-) mutants did not form the biofilm exhibited by the wild-type strain. These findings suggest that flagella-mediated motility as well as flagella is required for biofilm formation in vitro.
authors.affiliation: Laboratory of Veterinary Public Health, Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki.
authors.forename: Kyaw Kyaw
authors.initials: KK
authors.lastname: Moe
authors.forename: Junichiro
authors.initials: J
authors.lastname: Mimura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Wake
authors.forename: Wataru
authors.initials: W
authors.lastname: Yamazaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakai
authors.forename: Naoaki
authors.initials: N
authors.lastname: Misawa
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development; D002169:Campylobacter Infections / Q000382:microbiology; D016123:Campylobacter jejuni / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure; D017931:DNA Primers; D005407:Flagella / Q000502:physiology; D005898:Glass; D000882:Haplorhini; D006801:Humans; D007613:Kanamycin Resistance / Q000235:genetics; D008855:Microscopy, Electron, Scanning; D016133:Polymerase Chain Reaction; D011143:Polyvinyl Chloride; D013193:Stainless Steel; D013499:Surface Properties
chemical_list: D017931:DNA Primers; D013193:Stainless Steel; D011143:Polyvinyl Chloride