What is Segmented Filamentous Bacteria (SFB)?

Segmented filamentous bacteria (SFB) are gram-positive, spore-forming bacteria that were originally identified in the ilia of mice and rats. The first publication about these unique filamentous bacteria appeared in 19741. Since that time, SFB have been identified in the ilia of several other species including rabbits, guinea pigs, cattle, pigs, cats, turkeys, horses and humans2. Interestingly, all SFB appear to be host-specific. SFB have yet to be grown in culture, but metagenomic comparisons have identified these organisms as close relatives of Clostridium spp.3.

Taconic offers animals at a variety of health standards, including Excluded Flora (EF), which is maintained free of SFB. For guidance in selecting an appropriate health status for your study, please follow this link, or contact us at info@taconic.com.
There is still much to be learned about these commensal organisms, but their role in both adaptive and innate immune responses cannot be ignored. Since their discovery, many publications have identified them as a key component in many experimental models (see Comparative Medicine4 for a recent review). It is beyond the scope of this summary to provide details of these findings, but a few of these systems include:

  • T-helper cell development and activation5,6
  • IgA production7,8
  • Role in autoimmune diseases9,10
  • Influence on the development of the gut immune system11,12,13
Many disease models are now known to be impacted by the gut microbiome. Reproducibility is always a challenge in animal models especially ones that may be influenced by the gut flora. To help researchers make better decisions about the animals they use in their studies, Taconic strives to provide as much information as possible about our models. While SFB is only one component of the gut microbiome, for many models the impact could be significant. For that reason, Taconic is now including SFB on our health reports, and SFB is specifically excluded in our EF health status.

If you have specific questions regarding SFB or microbiome studies, please contact Taconic at info@taconic.com.

For questions regarding diagnostic testing for SFB please contact us.

Works Cited:

1. Habitat, succession, attachment, and morphology of segmented, filamentous microbes indigenous to the murine gastrointestinal tract. Davis CP, Savage DC. 1974, Infection and Immunity, pp. 948-956.
2. Intestinal, segmented, filamentous bacteria in a wide range of vertebrate species. Klaasen HL, Koopman JP, Van den Brink ME, Bakker MH, Poelma FG, Beynen AC. 1993, Lab Animal, pp. 141-150.
3. Complete genome sequences of rat and mouse segmented filamentous bacteria, a potent inducer of Th17 cell differentiation. . Prakash T, Oshima K, Morita H, Fukuda S, Imaoka A, Kumar N, Sharma VK, Kim SW, Takahashi M, Saitou N, Taylor TD, Ohno, H, Umesaki Y, Hattori M. 2011, Cell Host Microbe, pp. 273-284.
4. Segmented filamentous bacteria: commensal microbes with potential effects on research. Ericsson AC, Hagan CE, Davis DJ, Franklin CL. 2014, Comparative Medicine, pp. 90-98.
5. Induction of intestinal Th17 cells by segmented filamentous bacteria. Ivanov II, Atarashi K, Manel N, Brodie EL, Shima T, Karaoz U, Wei D, Goldfarb KC, Santee CA, Lynch SV, Tanoue T, Imaoka A, Itoh K, Takeda K, Umesaki Y, Honda K, Littman DR. 2009, Cell, pp. 485-498.
6. Segmented filamentous bacterium uses secondary and tertiary lymphoid tissues to induce gut IgA and specific T helper 17 cell responses. Lécuyer E, Rakotobe S, Lengliné-Garnier H, Lebreton C, Picard M, Juste C, Fritzen R, Eberl G, McCoy KD, Macpherson AJ, Reynaud CA, Cerf-Bensussan N, Gaboriau-Routhiau V. 2014, Immunity, pp. 608-620.
7. Apathogenic, intestinal, segmented, filamentous bacteria stimulate the mucosal immune system of mice. Klaasen HL, Van der Heijden PJ, Stok W, Poelma FG, Koopman JP, Van den Brink ME, Bakker MH, Eling WM, Beynen AC. 1993, Infection and Immunity, pp. 303-306.
8. Differential roles of segmented filamentous bacteria and clostridia in development of the intestinal immune system. Umesaki Y, Setoyama H, Matsumoto S, Imaoka A, Itoh K. 1999, Infection and Immunity, pp. 3504-3511.
9. Specific gut commensal flora locally alters T cell tuning to endogenous ligands. Chappert P, Bouladoux N, Naik S, Schwartz RH. 2013, Immunity, pp. 1198-1210.
10. Role of SFB in autoimmune arthritis: an example of regulation of autoreactive T cell sensitivity in the gut. P., Chappert. 2014, Gut Microbes, pp. 259-264.
11. Host interactions with Segmented Filamentous Bacteria: an unusual trade-off that drives the post-natal maturation of the gut immune system. Schnupf P1, Gaboriau-Routhiau V, Cerf-Bensussan N. 2013, Seminars in Immunology, pp. 342-351.
12. Segmented filamentous bacteria are potent stimuli of a physiologically normal state of the murine gut mucosal immune system. Talham GL, Jiang HQ, Bos NA, Cebra JJ. 1999, Infection and Immunity, pp. 1992-2000.
13. Segmented filamentous bacteria are indigenous intestinal bacteria that activate intraepithelial lymphocytes and induce MHC class II molecules and fucosyl asialo GM1 glycolipids on the small intestinal epithelial cells in the ex-germ-free mouse. Umesaki Y, Okada Y, Matsumoto S, Imaoka A, Setoyama H. 1995, Microbial Immunology, pp. 555-562.