Lifestyle and Horizontal Gene Transfer-Mediated Evolution ofMucispirillum schaedleri, a Core Member of the Murine Gut Microbiota.
Mucispirillum schaedleriis an abundant inhabitant of the intestinal mucus layer of rodents and other animals and has been suggested to be a pathobiont, a commensal that plays a role in disease. In order to gain insights into its lifestyle, we analyzed the genome and transcriptome ofM. schaedleriASF 457 and performed physiological experiments to test traits predicted by its genome. Although described as a mucus inhabitant,M. schaedlerihas limited capacity for degrading host-derived mucosal glycans and other complex polysaccharides. Additionally,M. schaedlerireduces nitrate and expresses systems for scavenging oxygen and reactive oxygen speciesin vivo, which may account for its localization close to the mucosal tissue and expansion during inflammation. Also of note,M. schaedleriharbors a type VI secretion system and putative effector proteins and can modify gene expression in mucosal tissue, suggesting intimate interactions with its host and a possible role in inflammation. TheM. schaedlerigenome has been shaped by extensive horizontal gene transfer, primarily from intestinalEpsilon- andDeltaproteobacteria, indicating that horizontal gene transfer has played a key role in defining its niche in the gut ecosystem.IMPORTANCEShifts in gut microbiota composition have been associated with intestinal inflammation, but it remains unclear whether inflammation-associated bacteria are commensal or detrimental to their host. Here, we studied the lifestyle of the gut bacteriumMucispirillum schaedleri, which is associated with inflammation in widely used mouse models. We found thatM. schaedlerihas specialized systems to handle oxidative stress during inflammation. Additionally, it expresses secretion systems and effector proteins and can modify the mucosal gene expression of its host. This suggests thatM. schaedleriundergoes intimate interactions with its host and may play a role in inflammation. The insights presented here aid our understanding of how commensal gut bacteria may be involved in altering susceptibility to disease.
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria.
Alexander
A
Loy
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria.
Carina
C
Pfann
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria.
Michaela
M
Steinberger
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria.
Buck
B
Hanson
Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Ludwig Maximilians University of Munich, and German Center for Infection Research (DZIF), Partner Site LMU Munich, Munich, Germany.
Simone
S
Herp
Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Ludwig Maximilians University of Munich, and German Center for Infection Research (DZIF), Partner Site LMU Munich, Munich, Germany.
Sandrine
S
Brugiroux
Food Science and Technology Department, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
João Carlos
JC
Gomes Neto
Nutrition, Metabolism, and Genomics Group, Wageningen University, Wageningen, the Netherlands.
Mark V
MV
Boekschoten
Archaea Biology and Ecogenomics Division, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria.
Clarissa
C
Schwab
Archaea Biology and Ecogenomics Division, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria.
Tim
T
Urich
Food Science and Technology Department, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
Amanda E
AE
Ramer-Tait
Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
Thomas
T
Rattei
Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Ludwig Maximilians University of Munich, and German Center for Infection Research (DZIF), Partner Site LMU Munich, Munich, Germany.
Bärbel
B
Stecher
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria.
David
D
Berry
DNRA; Deferribacteres; Helicobacter; fluorescence in situ hybridization; gut microbiota; metatranscriptomics