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Chelsie                        Armbruster

Chelsie E. Armbruster PhD

Department of Microbiology and Immunology

Assistant Professor

 
Professional Summary:

My laboratory is broadly focused on investigating microbe-microbe interactions, host-microbe interactions, and patient characteristics that influence disease severity. Our primary disease model is catheter-associated urinary tract infection (CAUTI), one of the most common healthcare-associated infections worldwide. Long-term use of indwelling catheters, which is common for management of certain conditions particularly in aging populations, results in continuous urine colonization by bacteria (bacteriuria) and can lead to infections of the bladder (cystitis), kidneys (pyelonephritis), and bloodstream (bacteremia).

My lab uses a combination of basic science and patient-oriented research, with the long-term goals of 1) identifying the uropathogen(s) most likely to cause symptomatic infection and adverse outcomes in patients, 2) utilizing an experimental model of infection to identify key virulence factors of these organisms, and 3) developing inhibitors of the identified virulence factors to reduce colonization and infection severity in vulnerable patient populations. As bacteriuria and CAUTI are frequently polymicrobial, which can influence the progression of the infection and the efficacy of antibiotic therapy, a major emphasis of this work is on understanding the contribution of polymicrobial colonization and microbe-microbe interactions to infection progression.

We recently identified the Gram-negative bacterium Proteus mirabilis as the most common cause of CAUTI in a cohort of nursing home residents, including cases of polymicrobial infection. P. mirabilis is well-known for its potent urease enzyme, which produces ammonia from the hydrolysis of urea in urine and leads to high urine pH, precipitation of polyvalent ions, and formation of urinary stones (urolithiasis). We recently determined that P. mirabilis urease activity is enhanced during co-culture with other common uropathogens in vitro and in vivo, contributing to increased tissue damage and bacteremia. Enhanced urease activity appears to be a broad phenomenon, occurring with numerous isolates of P. mirabilis during co-culture with most of the other common uropathogens, including Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Therefore, one project in the lab focuses on defining the underlying mechanism of enhanced urease activity and determining its potential as a therapeutic target.

Another focus of the lab is utilizing genome-wide screens to uncover new genes that contribute to pathogenesis during both monomicrobial and polymicrobial infection. We are using transposon insertion-site sequencing (Tn-Seq) to identify the full potential arsenal of P. mirabilis fitness and virulence factors during experimental CAUTI, including core factors that contribute to pathogenicity under all infection conditions tested, and accessory factors that are only required under certain infection conditions.

Education and Training:
  • PhD, Microbiology and Immunology, Wake Forest University School of Medicine (2011)
  • BS, Biotechnology, Rochester Institute of Technology, Honors (2007)
Employment:
  • Assistant Professor, Microbiology and Immunology, State University of New York at Buffalo (2017-present)
  • Research Investigator, Microbiology and Immunology, University of Michigan Medical School (2016–2017)
  • Post Doctoral Fellow, Microbiology and Immunology, University of Michigan Medical School (2011–2016)
  • Graduate Student, Microbiology and Immunology, Wake Forest University School of Medicine (2007–2011)
Awards and Honors:
  • American Society for Microbiology Travel Award (2014)
  • University of Michigan Department of Microbiology and Immunology Travel Award (2013)
  • Mid-Atlantic Microbial Pathogenesis Meeting Travel Award (2011)
  • Gordon A. Melson Outstanding Student Award Nominee/Runner-up (2011)
  • NIH National Graduate Student Research Festival Travel Award (2010)
  • CAP Student Travel Award (2009)
  • Best Poster Award (2009)
  • Outstanding Undergraduate Scholar (2006)
  • Honors Program Scholarship (2004)
  • Presidential Merit Scholarship (2003)

Research Expertise:
  • Bacterial pathogens: Proteus mirabilis, Providencia stuartii, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis
  • Motility: Swimming and swarming
  • Polymicrobial infections: Urinary tract infection (UTI), catheter-associated urinary tract infection (CAUTI), bacteremia, otitis-media
  • Urease: Enzymatic activity during co-culture of uropathogens, and contribution to pathogenesis
Grants and Sponsored Research:
  • September 2015–August 2017
    Pathogenesis of Polymicrobial Catheter-Associated Urinary Tract Infection
    National Institute of Diabetes and Digestive and Kidney Diseases
    Role: Principal Investigator
    $194,400
  • August 2016–July 2017
    Influence of aging on Proteus mirabilis urinary tract infection
    University of Michigan Geriatrics Center
    Role: Principal Investigator
    $40,000
  • June 2012–May 2015
    Proteus mirabilis swarming: Initiation and role during urinary tract infection
    National Institute of Allergy and Infectious Diseases
    Role: Principal Investigator
    $156,498
  • April 2014–October 2014
    Synergistic urease activity in polymicrobial catheter-associated urinary tract infections
    University of Michigan Grants and Awards Program
    Role: Co-Investigator
    $12,360

Journal Articles:
See all (4 more)
Books and Book Chapters:
  • Armbruster CE, Mobley HTL, Pearson MM. Pathogenesis of Proteus mirabilis Infection..

Professional Memberships:
  • Infectious Diseases Society of America (2016–present)
  • American Society for Microbiology (2004–present)
Presentations:
  • "Relatedness of MRSA and VRE strains isolated from post-acute care patients and their environment: a longitudinal assessment" IDWeek, Infectious Diseases Society of America (2017)
  • "Comparison of Methods for Estimating in vivo Growth Rate During Urinary Tract Infection" ASM Microbe 2017, American Society for Microbiology (2017)
  • "Genome-Wide Transposon Mutagenesis of Proteus mirabilis: Essential Genes, Fitness Factors for Catheter-Associated Urinary Tract Infection, and the Impact of Polymicrobial Infection On Fitness Requirements" ASM Microbe 2017, American Society for Microbiology (2017)
  • "Transposon Insertion Sequencing to Identify Providencia stuartii Essential Genes and Fitness Factors for Murine Catheter-Associated Urinary Tract Infection" ASM Microbe 2017, American Society for Microbiology (2017)
  • "Burgeoning Short Stay Population: Impact on transmission of Multi-Drug Resistant Organisms (MDROs)" AGS 2017 Annual Meeting, American Geriatrics Society (2017)
  • "Influence of Aging on Urinary Tract Infection Susceptibility and Severity" Claude D. Pepper Older Americans Independence Centers Annual Meeting, Claude D. Pepper Older Americans Independence Centers Annual Meeting (2017)
  • "Multidrug-Resistant Organisms (MDRO) in Post-Acute Care: Dynamics From Admission Through Discharge" IDWeek, Infectious Diseases Society of America (2016)
  • "Urease activity is enhanced during co-culture of common CAUTI pathogens and contributes to severity of disease in a murine infection model" IDWeek, Infectious Diseases Society of America (2016)
  • "Urease Activity is Enhanced During Experimental Polymicrobial UTI And Promotes Tissue Damage and Bacteremia" Clinical and Scientific Advances in Urinary Tract Infections (2016)
  • "Delineating the Role of Enhanced Urease Activity in Tissue Damage and Bacteremia During Polymicrobial Urinary Tract Infection" ASM Microbe 2016, American Society for Microbiology (2016)
  • "Measuring Differential Growth Rates of Uropathogenic Escherichia coli Strains in vitro and During Experimental Murine Urinary Tract Infection" ASM Microbe 2016, American Society for Microbiology (2016)
  • "Partners in Crime: Enhanced urease activity during co-culture of bacterial uropathogens" ASM Microbe 2016, American Society for Microbiology (2016)
  • "Transposon Insertion Sequencing to Identify Proteus mirabilis Fitness Factors for Murine Catheter-Associated Urinary Tract Infection" ASM Microbe 2016, American Society for Microbiology (2016)
  • "Klebsiella pneumoniae Catheter-Associated Urinary Tract Infections are Associated with Acute Changes in Mental Status" IDWeek, Infectious Diseases Society of America (2015)
  • "Double Trouble: Coinfection with Proteus mirabilis and Providencia stuartii Enhances the Severity of Catheter-Associated Urinary Tract Infection" Molecular Pathogenesis: Mechanisms of Infectious Disease, Federation of American Societies for Experimental Biology (2015)
  • "Contribution of Bacterial Urease to Enhanced Pathogenicity During Polymicrobial Urinary Tract Infection" ASM General Meeting, American Society for Microbiology (2015)
  • "Synergistic urease activity in vitro and during experimental polymicrobial urinary tract infection" ASM General Meeting, American Society for Microbiology (2015)
  • "Investigating Molecular Mechanisms of Enhanced Pathogenicity during Polymicrobial Urinary Tract Infection" 1st ASM Conference on Polymicrobial Infections, American Society for Microbiology (2014)
  • "Polymicrobial Infections" 1st ASM Conference on Polymicrobial Infections, American Society for Microbiology (2014)
  • "Synergistic urease activity during experimental polymicrobial urinary tract infection" 1st ASM Conference on Polymicrobial Infections, American Society for Microbiology (2014)
  • "Synergistic urease activity and increased incidence of bacteremia and urolithiasis resulting from coinfection of the urinary tract" ASM General Meeting, American Society for Microbiology (2014)
  • "Proteus mirabilis swarming occurs in response to factors present in urine and requires excess L-glutamine" Clinical and Scientific Advances in Urinary Tract Infections (2013)
  • "Proteus mirabilis swarming occurs in response to factors present in urine and requires excess L-glutamine" ASM General Meeting, American Society for Microbiology (2013)
  • "Proteus mirabilis swarming motility: influence of amino acids, polyamine synthesis, and metabolism" ASM General Meeting, American Society for Microbiology (2012)
  • "Identification of factors that trigger Proteus mirabilis swarming motility" 18th Annual Midwest Microbial Pathogenesis Conference (2011)
See all (15 more)
Service Activities:
  • Peer Review; Infection, Disease & Health (Elsevier); Ad Hoc Reviewer (2017–present)
  • Peer Review; Medical Microbiology and Immunology (Springer); Ad Hoc Reviewer (2017–present)
  • Peer Review; Journal of Infection (Elsevier); Ad Hoc Reviewer (2016–present)
  • Peer Review; Methods (Elsevier); Ad Hoc Reviewer (2016–present)
  • Peer Review; Microbiology (Society for General Microbiology); Ad Hoc Reviewer (2015–present)
  • Planning committee and primary organizer; Fall 2015 meeting of the Michigan branch of the American Society for Microbiology; Organizing Committee Member (2015)
  • Peer Review; Clinical and Vaccine Immunology (American Society for Microbiology); Ad Hoc Reviewer (2015–present)
  • President; University of Michigan Microbiology & Immunology Departmental Postdoctoral Association; President (2015)
  • Peer Review; Infection and Immunity (ASM); Ad Hoc Reviewer (2014–present)
  • Peer Review; Applied Environmental Microbiology (ASM); Ad Hoc Reviewer (2014–present)
  • Peer Review; Antimicrobial Agents and Chemotherapy (ASM); Ad Hoc Reviewer (2014–present)
  • Peer Review; Clinical Microbiology Reviews (ASM); Ad Hoc Reviewer (2013–present)
  • Vice President; University of Michigan Microbiology & Immunology Departmental Postdoctoral Association; Vice President (2012)

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Contact Information

Biomedical Research Building
Room 115
3435 Main Street
Buffalo, NY 14214
Phone: (716) 829-6059
Email: chelsiea@buffalo.edu


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