Lifestyle and Horizontal Gene Transfer-Mediated Evolution of <named-content content-type="genus-species">Mucispirillum schaedleri</named-content>, a Core Member of the Murine Gut Microbiota
Alexander Loy,
Carina Pfann,
Michaela Steinberger,
Buck Hanson,
Simone Herp,
Sandrine Brugiroux,
João Carlos Gomes Neto,
Mark V. Boekschoten,
Clarissa Schwab,
Tim Urich,
Amanda E. Ramer-Tait,
Thomas Rattei,
Bärbel Stecher,
David Berry
Affiliations
Alexander Loy
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria
Carina Pfann
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria
Michaela Steinberger
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria
Buck Hanson
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria
Simone 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 Brugiroux
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
João Carlos Gomes Neto
Food Science and Technology Department, University of Nebraska—Lincoln, Lincoln, Nebraska, USA
Mark V. Boekschoten
Nutrition, Metabolism, and Genomics Group, Wageningen University, Wageningen, the Netherlands
Clarissa Schwab
Archaea Biology and Ecogenomics Division, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
Tim Urich
Archaea Biology and Ecogenomics Division, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
Amanda E. Ramer-Tait
Food Science and Technology Department, University of Nebraska—Lincoln, Lincoln, Nebraska, USA
Thomas Rattei
Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
Bärbel Stecher
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
David Berry
Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, University of Vienna, Austria
ABSTRACT Mucispirillum schaedleri is 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 of M. schaedleri ASF 457 and performed physiological experiments to test traits predicted by its genome. Although described as a mucus inhabitant, M. schaedleri has limited capacity for degrading host-derived mucosal glycans and other complex polysaccharides. Additionally, M. schaedleri reduces nitrate and expresses systems for scavenging oxygen and reactive oxygen species in vivo, which may account for its localization close to the mucosal tissue and expansion during inflammation. Also of note, M. schaedleri harbors 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. The M. schaedleri genome has been shaped by extensive horizontal gene transfer, primarily from intestinal Epsilon- and Deltaproteobacteria, indicating that horizontal gene transfer has played a key role in defining its niche in the gut ecosystem. IMPORTANCE Shifts 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 bacterium Mucispirillum schaedleri, which is associated with inflammation in widely used mouse models. We found that M. schaedleri has 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 that M. schaedleri undergoes 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.
