title: Stress tolerance of Methylobacterium biofilms in bathrooms.
abstract: A comprehensive survey of microbial flora within pink biofilms in bathrooms was performed. Pink biofilms develop relatively rapidly in bathrooms, can be difficult to remove, and are quick to recur. Bacterium-sized cells were found to be predominant in 42 pink biofilms in Japan using a scanning electron microscope. Methylobacterium strains were detected from all samples in bathrooms by an isolation method. To explain this predominance, 14 biofilm samples were analyzed by fluorescence in situ hybridization. Methylobacterium was indicated to be the major genus in all biofilms. The isolated Methylobacterium survived after contact with 1.0% cleaning agents, including benzalkonium chloride for 24 h. Their tolerance did not differ under biofilm-like conditions on fiber reinforced plastics (FRP), a general material of bath tubs, floors, and walls. Also, the strains exhibited higher tolerance to desiccation than other isolated species on FRP. Some Methylobacterium survived and exhibited potential to grow after four weeks of desiccation without any nutrients. These specific characteristics could be a cause of their predominance in bathrooms, an environment with rapid flowing water, drying, low nutrients, and occasional exposure to cleaning agents.
authors.affiliation: R&D-Safety Science Research, Kao Corporation, Tochigi, Japan.
authors.forename: Takehisa
authors.initials: T
authors.lastname: Yano
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kubota
authors.forename: Junya
authors.initials: J
authors.lastname: Hanai
authors.forename: Jun
authors.initials: J
authors.lastname: Hitomi
authors.forename: Hajime
authors.initials: H
authors.lastname: Tokuda
mesh_terms: D001548:Benzalkonium Compounds / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D003890:Desiccation; D003902:Detergents / Q000494:pharmacology*; D018869:Heat-Shock Response; D007564:Japan; D020580:Methylobacterium / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D001548:Benzalkonium Compounds; D004269:DNA, Bacterial; D003902:Detergents; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate