title: The genome of th17 cell-inducing segmented filamentous bacteria reveals extensive auxotrophy and adaptations to the intestinal environment.
abstract: Perturbations of the composition of the symbiotic intestinal microbiota can have profound consequences for host metabolism and immunity. In mice, segmented filamentous bacteria (SFB) direct the accumulation of potentially proinflammatory Th17 cells in the intestinal lamina propria. We present the genome sequence of SFB isolated from monocolonized mice, which classifies SFB phylogenetically as a unique member of Clostridiales with a highly reduced genome. Annotation analysis demonstrates that SFB depend on their environment for amino acids and essential nutrients and may utilize host and dietary glycans for carbon, nitrogen, and energy. Comparative analyses reveal that SFB are functionally related to members of the genus Clostridium and several pathogenic or commensal "minimal" genera, including Finegoldia, Mycoplasma, Borrelia, and Phytoplasma. However, SFB are functionally distinct from all 1200 examined genomes, indicating a gene complement representing biology relatively unique to their role as a gut commensal closely tied to host metabolism and immunity.
authors.affiliation: Molecular Pathogenesis Program, The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Sczesnak
authors.forename: Nicola
authors.initials: N
authors.lastname: Segata
authors.forename: Xiang
authors.initials: X
authors.lastname: Qin
authors.forename: Dirk
authors.initials: D
authors.lastname: Gevers
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Petrosino
authors.forename: Curtis
authors.initials: C
authors.lastname: Huttenhower
authors.forename: Dan R
authors.initials: DR
authors.lastname: Littman
authors.forename: Ivaylo I
authors.initials: II
authors.lastname: Ivanov
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D018407:Bacterial Physiological Phenomena; D003013:Clostridium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D016680:Genome, Bacterial; D006801:Humans; D007422:Intestines / Q000276:immunology / Q000382:microbiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D058504:Th17 Cells / Q000276:immunology / Q000382:microbiology*