title: Bacillus subtilis isolated from the human gastrointestinal tract.
abstract: As part of an ongoing study to determine the true habitat of Bacillus species, we report here the isolation and characterisation of Bacillus subtilis from the human gastrointestinal tract (GIT). Strains were obtained from ileum biopsies as well as from faecal samples and their biotypes defined. 16S rRNA analysis revealed that most isolates of B. subtilis were highly conserved, in contrast to RAPD-PCR fingerprinting that showed greater diversity with 23 distinct RAPD types. The majority of B. subtilis strains examined possessed features that could be advantageous to survival within the GIT. This included the ability to form biofilms, to sporulate anaerobically and secretion of antimicrobials. At least one isolate was shown to form spores that carried an exosporium, a loosely attached outer layer to the mature endospore, this being the first report of B. subtilis spores carrying an exosporium. This study reinforces a growing view that B. subtilis and probably other species have adapted to life within the GIT and should be considered gut commensals rather than solely soil microorganisms.
authors.affiliation: School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK.
authors.forename: Huynh A
authors.initials: HA
authors.lastname: Hong
authors.forename: Reena
authors.initials: R
authors.lastname: Khaneja
authors.forename: Nguyen M K
authors.initials: NM
authors.lastname: Tam
authors.forename: Alessia
authors.initials: A
authors.lastname: Cazzato
authors.forename: Sisareuth
authors.initials: S
authors.lastname: Tan
authors.forename: Maria
authors.initials: M
authors.lastname: Urdaci
authors.forename: Alain
authors.initials: A
authors.lastname: Brisson
authors.forename: Antonio
authors.initials: A
authors.lastname: Gasbarrini
authors.forename: Ian
authors.initials: I
authors.lastname: Barnes
authors.forename: Simon M
authors.initials: SM
authors.lastname: Cutting
mesh_terms: D000328:Adult; D001412:Bacillus subtilis / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D001422:Bacterial Adhesion; D004269:DNA, Bacterial / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D020459:Genes, rRNA / Q000235:genetics; D006801:Humans; D007082:Ileum / Q000382:microbiology; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D013171:Spores, Bacterial / Q000648:ultrastructure
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S