Dynamics of Microeukaryotes and Archaea in the Mammalian Gut Microbiome
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University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2013 Dynamics of Microeukaryotes and Archaea in the Mammalian Gut Microbiome Serena Nicole Dollive University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Bioinformatics Commons, and the Microbiology Commons Recommended Citation Dollive, Serena Nicole, "Dynamics of Microeukaryotes and Archaea in the Mammalian Gut Microbiome" (2013). Publicly Accessible Penn Dissertations. 749. https://repository.upenn.edu/edissertations/749 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/749 For more information, please contact [email protected]. Dynamics of Microeukaryotes and Archaea in the Mammalian Gut Microbiome Abstract The vertebrate microbiome consists of the bacteria, fungi, archaea, protozoans, and viruses that inhabit the body at diverse locations including the skin, mouth, upper airways, urogenital tract, and digestive tract. These microorganisms are known to synthesize vitamins, interact with and tone the immune system, and dramatically affect human health. A long list of diseases has been associated with imbalances in commensal microbiome communities. The work presented in this dissertation aims to characterize the microeukaryotic and archaeal components of the gut microbiome through development of wet lab techniques and in silico methods, and apply them to the study of response to antibiotics. These methods provided a picture of the healthy fungal and archaeal communities in the gut, with high prevalence of the yeast Saccharomyces and the archaeon Methanobrevibactor, along with several other species. These new tools were then used to investigate the longitudinal changes that the microbiome undergoes when treated with heavy antibiotics. Using an antibiotic cocktail containing ampicillin, neomycin, vancomycin, and metronidazole in a mouse model, we found that bacterial communities were effectively suppressed and fungi grew out by one to two orders of magnitude. After we discontinued antibiotics, bacterial and fungal cell counts returned to baseline levels within one week, but community composition was still significantly altered. Eight weeks after cessation of antibiotics, fungal community composition was not significantly different from non-treated controls, but several mice continued to have elevated levels of yeasts that had grown out during antibiotic treatment. The bacterial community composition was still significantly different from non-treated controls. Ultimately, this work demonstrated potentially deleterious long term effects of antibiotic use, and emphasizes how strong cage effects can be in mouse studies. The research performed in this dissertation will aid researchers looking to study all three domains of life and take into account the effects of commonly used antibiotics in future microbiome studies. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Genomics & Computational Biology First Advisor Frederic D. Bushman Keywords Archaea, Fungi, Gut, ITS, Microbiome, Microeukaryotes Subject Categories Bioinformatics | Microbiology This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/749 DYNAMICS OF MICROEUKARYOTES AND ARCHAEA IN THE MAMMALIAN GUT MICROBIOME Serena Dollive A DISSERTATION in Genomics and Computational Biology Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2013 Supervisor of Dissertation ________________________ Frederic D. Bushman, Ph.D., Professor, Microbiology Graduate Group Chairperson ________________________ Maja Bucan, Ph.D., Professor, Genetics Dissertation Committee Christian J. Stoekert, Ph.D., Research Professor of Genetics Ronald G. Collman, M.D., Professor of Medicine Hongzhe Li, Ph.D., Professor of Biostatistics Paul D. Sniegowski, Ph.D., Assistant Professor of Biology DYNAMICS OF MICROEUKARYOTES AND ARCHAEA IN THE MAMMALIAN GUT MICROBIOME COPYRIGHT 2013 Serena Nicole Dollive Dedication To my mother, who has always been there for me. iii ACKNOWLEDGMENTS I would first like to thank my advisor, Rick Bushman for his scientific tutelage, support, and persistent championing for forward motion. Under Rick’s mentorship, I have not just developed as a scientist but gained a wide set of life skills that will be invaluable going forward. I would also like to thank our collaborators in the Human Microbiome Project at Penn. I am especially obliged to Gary Wu and Jim Lewis for their help, support, advice, and insights. I am also grateful to my thesis committee members: Chris Stoeckert, Ron Collman, Hongzhe Li, and Paul D. Sniegowski, for their time, knowledge, recommendations, and investment in my graduate career. I am thankful for the lessons and skills I have learned from fellow lab members. Chris Hoffmann taught me nearly all of the wet lab techniques I know today and had an immense amount of patience with me as a very green rotation student. Through my years in the Bushman Lab, Chris has been unbelievably helpful and a great friend. I am indebted to Kyle Bittinger for his advice, cheerleading, and persistent willingness to put aside his work and teach me. I am thankful to my former baymate Shoshanna Roth who took the time to help me navigate through the academic world as a beginning graduate student. I am also grateful to Ying-Yu Chen and Stephanie Grunberg for amount of work and effort they put into the collaborative projects in this dissertation. I am obliged to the microbiology graduate students in the Bushman lab whose graduate careers coincided with mine: Emily Charlson, Greg Peterfreund, and Sam Minot. Having companions with whom I could commiserate and celebrate from classes to dissertation was incredibly heartening. I am glad for the support and friendship from past and present lab members: Rohini Sinha, Nirav Malani, Aubrey Bailey, Young Hwang, Jimmy Hu, Sana Attar, Brendan Kelly, Frances Male, Troy Brady, Alexandra Bryson, Jacque Young, Troy Brady, iv Rebecca Custers-Allen, Jennifer Hwang, Christel Chehoud, Erik Clarke, Karen Ocwieja, Mali Skotheim, Caitlin Greig, and Laurie Zimmerman. I am also extremely grateful for the support of the GCB faculty and students. Their enthusiasm and eagerness to help made my graduate student carrier so much more enlightening and exciting. I am particularly indebted to Maja Bucan, who encouraged and supported me. I am very appreciative of my fellow GCB graduate students whose friendship and solidarity bettered my graduate school experience. I am thankful to have had collaborative and congenial cohort- mates in Ellen Tsai, Aleah Caulin, Nick Stong, and Sira Sriswasdi, whose comradery made prelims bearable. I am glad to have been able to get to know and spend time with many of my GCB classmates, including Scott Sherrill-Mix, Rithun Mukherjee, Hannah Dueck, Yih-Chii Hwang, Sarah Middleton, Varun Aggarwala, Fan Li, Kathleen Sprouffske, Rumen Kostadinov, Paul Ryvkin, Jun Chen, Anthony Olarerin, Miler Lee, Erik Clarke, Hannah Hutton, Ryan Coleman, Brett Hannigan, Najaf Shah, and others. I am especially grateful to Hannah Chervitz and Tiffany Barlow for their continual support and help over the past five years. I would like to acknowledge the friends I have made at Penn who have made Philadelephia my home. Friends like Lauren Friedman, Kristy Skowronski, Shanshan Ding, Yiwen Song, Grace Chao, Katherine O’Brien, Siqing He, Viktoriya Syrovatkina, Judite Costa, and Anton Kutovoy made the years I have spent at Penn wonderful. I would like to thank my family: my mother, Janice, my siblings, Blake and Monica, my grandmother, Virginia, my Aunt Kathy, Uncle John, Uncle Cliff, cousins Brian and Tim, and partner and best friend Tom who have been my biggest fans and supporters. v ABSTRACT DYNAMICS OF MICROEUKARYOTES AND ARCHAEA IN THE MAMMALIAN GUT MICROBIOME Serena Dollive Fredrick D. Bushman The vertebrate microbiome consists of the bacteria, fungi, archaea, protozoans, and viruses that inhabit the body at diverse locations including the skin, mouth, upper airways, urogenital tract, and digestive tract. These microorganisms are known to synthesize vitamins, interact with and tone the immune system, and dramatically affect human health. A long list of diseases has been associated with imbalances in commensal microbiome communities. The work presented in this dissertation aims to characterize the microeukaryotic and archaeal components of the gut microbiome through development of wet lab techniques and in silico methods, and apply them to the study of response to antibiotics. These methods provided a picture of the healthy fungal and archaeal communities in the gut, with high prevalence of the yeast Saccharomyces and the archaeon Methanobrevibactor, along with several other species. These new tools were then used to investigate the longitudinal changes that the microbiome undergoes when treated with heavy antibiotics. Using an antibiotic cocktail containing ampicillin, neomycin, vancomycin, and metronidazole in a mouse model, we found that bacterial communities were effectively suppressed and fungi grew out by one to two orders of magnitude. After we discontinued antibiotics, bacterial and fungal cell counts returned to baseline levels within one week, but community composition was still significantly altered. Eight weeks after cessation of antibiotics, fungal community composition was