In September 2023, several members of Dr. Gary Wang’s laboratory, including all graduate students, actively participated and presented posters at the 13th International Conference on the Molecular Biology and Pathogenesis of Clostridia (ClostPath 13) held in the picturesque locale of Banff, Canada. The conference featured top investigators in clostridial research presenting recent discoveries through lectures and selected abstracts. The conference promotes inclusivity, with a diverse speaker lineup and interactive poster sessions for attendees to share their latest work. Emphasizing the next generation, a Pre-ClostPath Meeting for Young Scientists and a Junior Scientist Session provided platforms for trainees to network and showcase their impactful research.
Abstract:
Metabolomics guided medium for culturing uncultivable murine gut microbiota.
Preethi Sudhakara, M.Tech1; James P Martin, M.S.1; Joan A Whitlock, B.S.1, Timothy J. Garrett, Ph.D.2; Gurjit S Sidhu, Ph.D.1; Gary P. Wang, M.D.,Ph.D.1,3*
1Division of Infectious Disease and Global Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA.
2Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
3Infectious Diseases Section, Medical Service, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
*Correspondence: gary.wang@medicine.ufl.edu
Abstract:
Commensal gut microbiota is crucial for protecting the host against enteric pathogens including Clostridioides difficile (C. difficile), a major cause of healthcare-associated infections. However, studying the role of specific gut microbes in mouse models of C. difficile infection (CDI) can be challenging due to difficulties in culturing most murine gut microbes. Here, we used comparative fecal metabolomics to guide the design of media to facilitate cultivation of novel murine microbes. We colonized germ-free (GF) C57BL/6 mice with serial dilutions of conventional murine fecal microbiota, and then challenged with C. difficile spores. Mice harboring higher dilutions of fecal microbiota succumbed to CDI, whereas mice with lower dilutions were resistance to C. difficile challenge. We then compared fecal samples from C. difficile susceptible and resistance mice using targeted and untargeted metabolomics. Fecal metabolites from C. difficile-resistant mice were enriched in glucose but depleted in sucrose, trehalose, sorbitol, raffinose, lactose, and mannitol, suggesting that C. difficile resistant microbiota preferentially utilized a variety of carbon source other than glucose. Using this information, we designed a novel growth medium and successfully cultured 22 unique murine gut microbes belonging to the Firmicutes phylum, including 18 that were not previously cultured or reported. Comparative fecal metabolomics may be a promising approach for designing novel culture media that enhance the cultivability of murine gut microbes relevant to C. difficile pathogenesis.
Keywords: commensal gut microbiota, novel medium, metabolomics, germ-free mice