= Emerging. More than 5 years before clinical availability. (19.79%)
= Expected to be clinically available in 1 to 4 years. (37.97%)
= Clinically available now. (42.25%)
MSACL 2022 : Prentice

MSACL 2022 Abstract

Self-Classified Topic Area(s): Imaging > Microbiology > Metabolomics

Podium Presentation in De Anza 1 on Thursday at 14:40 (Chair: Jeff Whitman)

Investigating Microbial Cooperation and Metabolic Communication During Clostrioles Difficile Infection Using Imaging Mass Spectrometry

Boone M. Prentice (1), Jonathan T. Specker (1), Alexander B. Smith (2), Joseph P. Zackular (2,3)
(1) Department of Chemistry, University of Florida, Gainesville, FL, 32611; USA. (2) Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, PA, 19104; USA. (3) Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104; USA.

Boone Prentice (Presenter)
University of Florida

Presenter Bio: Boone M. Prentice received his B.S. degree in Chemistry with Honors and Distinction from Longwood University (Farmville, VA) in 2008 with minors in Biology and Mathematics. At Longwood, he conducted electroanalytical research focused on developing biosensors under the supervision of Professor Melissa C. Rhoten. He attended graduate school at Purdue University (West Lafayette, IN) under the mentorship of Professor Scott A. McLuckey and received a Ph.D. in Chemistry in 2013. His Ph.D. research focused on ion trap mass spectrometry (MS) instrumentation development as well as gas-phase ion/ion and ion/molecule reactions involving biopolymers. Boone then worked as a postdoctoral research fellow in Professor Richard Caprioli’s laboratory at Vanderbilt University (Nashville, TN) where he studied matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) instrumentation and applications. Specifically, he worked on Fourier transform ion cyclotron resonance (FT-ICR) and time-of-flight (TOF) MS systems and applied IMS to the study of diabetes, cancer, drug delivery, and infectious disease. Boone joined the Department of Chemistry at the University of Florida as an Assistant Professor in the fall of 2018. His research focuses on developing next-generation bioanalytical mass spectrometry to better understand the molecular basis of health and disease.


INTRODUCTION: Imaging mass spectrometry is a powerful technology that enables the visualization of biochemical processes directly in tissues by combining the molecular specificity of mass spectrometry with the spatial fidelity of microscopic imaging. This label-free technology has proven exceptionally useful in areas of study such as cancer diagnosis, diabetes, and infectious disease. However, these types of modern imaging mass spectrometry studies are already stressing the limits of current analytical technologies and improvements are crucial in order to answer increasingly complicated biological and clinical questions. Research in our lab develops analytical instrumentation and methodologies in order to enable novel insights into disease mechanisms. For example, Clostriodioles difficile is an emerging human nosocomial pathogen and poses an urgent public health threat worldwide. During colonization in the gastrointestinal tract, C. difficile interacts with a widely diverse polymicrobial environment, including commensally found Enterococcus faecalis, which has been demonstrated to alter C. difficile growth morphology and virulence. However, little is known about the molecular mechanisms underlying these interactions.

OBJECTIVES: In order to study the role of metabolic cross-communication during C. difficile infection in the presence of E. faecalis, we have performed spatial mapping of metabolites using matrix-assisted laser/desorption/ionization (MALDI) imaging mass spectrometry in bacterial colonies and mouse models of infection.

METHODS: Specifically, we have leveraged continuous accumulation of selected ions (CASI) technology during MALDI imaging to enable the study of arginine metabolism as an important metabolic modulator in host immune responses. All experiments were performed on a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer (7T solariX, Bruker Daltonics).

RESULTS: Our studies indicate that E. faecalis uptakes arginine through the cell’s ArcD antiporter and concomitantly exports high levels of ornithine during arginine metabolism, which we hypothesize can be used by C. difficile as an energy resource to promote growth and virulence. Our animal studies involve mice harboring commensal E. faecalis that were infected with C. difficile following cefoperazone treatment, reveal significantly increased ornithine and significantly decreased arginine in co-infected ceca tissues. Subsequent imaging experiments have been conducted in germ-free mice, including C. difficile mono-infected and C. difficile + E. faecalis co-infected mouse models. These studies again reveal increased ornithine and decreased arginine. Finally, imaging of bacterial co-cultures and mouse ceca tissues have been performed using an E. faecalis ArcD knock out, which no longer possess the ability to import arginine or export ornithine. Arginine and ornithine distributions and abundances observed using the C. difficile + E. faecalis with the ArcD knock out again resemble the C. difficile mono-infected model (i.e., increased ornithine and decreased arginine levels).

CONCLUSIONS: These models demonstrate a dynamic relationship between arginine and ornithine production and C. difficile pathogenesis. Future work will involve extending these studies to human clinical samples.

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