Salmonellae are Enterobacteriaceae that cause a spectrum of diseases in humans and animals, including enteric (typhoid) fever and gastroenteritis. Typhoid fever, caused primarily by Salmonella enterica serovar Typhi (S. Typhi), is a life-threatening systemic disease that is responsible for significant morbidity and mortality annually worldwide. Approximately 3-5% of individuals infected with S. Typhi become chronic carriers with the gallbladder (GB) as the site of persistence. S. Typhi is a human-restricted pathogen, therefore asymptomatic carriers represent a critical reservoir for further spread of disease. We have demonstrated that gallstones aid in the development and maintenance of GB carriage in a mouse model and in humans, serving as a substrate to which salmonellae attach and form a protective biofilm. However, the molecular basis of chronic carriage of Salmonella in the GB, both from the host and bacterial perspectives, is poorly understood. Our goal is to better understand the environment that allows for asymptomatic chronic carriage and to develop therapies to reverse/prevent it.
In Aim 1 of this application, we will examine the ongoing dynamics of the GB response to Salmonella colonization in our gallstone mouse model to better understand the role of the host in permitting asymptomatic chronic carriage. We will focus on the role of immune factors in this process, including IL-10, which we have demonstrated to participate in the development of GB chronic colonization.
In Aim 2, we examine the bacterium throughout the establishment of chronic infection, including genes specifically expressed in carriers and putative GB-driven pathoadaptive mutations.
In Aim 3, we expand the development of novel treatments for chronic carriage that have emerged from our discovery research efforts. These approaches target kinases required for biofilm formation and the gallstone itself. This work will identify key host and bacterial factors at play during chronic infection of the GB by Salmonella, thus presenting new targets for therapeutic/preventive approaches to eliminate the carrier state.

Public Health Relevance

Research proposed in this application will support pioneering studies on the development and treatment of Salmonella gallbladder carriage (aka 'Typhoid Marys'). As we have demonstrated a role for Salmonella biofilm formation on gallstones as a primary mechanism of carriage, we propose to determine both the host (gallbladder) and bacterial responses that allow carriage to develop and persist. This work will also further develop novel therapeutic interventions to prevent the development/maintenance of S. Typhi gallbladder carriage.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI116917-04
Application #
9486875
Study Section
Bacterial Pathogenesis Study Section (BACP)
Program Officer
Alexander, William A
Project Start
2015-06-01
Project End
2020-05-31
Budget Start
2018-06-01
Budget End
2019-05-31
Support Year
4
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Ohio State University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Huggins, William M; Vu Nguyen, T; Hahn, Nicholas A et al. (2018) 2-Aminobenzimidazoles as antibiofilm agents against Salmonella enterica serovar Typhimurium. Medchemcomm 9:1547-1552
Moshiri, Jasmine; Kaur, Darpan; Hambira, Chido M et al. (2018) Identification of a Small Molecule Anti-biofilm Agent Against Salmonella enterica. Front Microbiol 9:2804
González, Juan F; Alberts, Halley; Lee, Joel et al. (2018) Biofilm Formation Protects Salmonella from the Antibiotic Ciprofloxacin In Vitro and In Vivo in the Mouse Model of chronic Carriage. Sci Rep 8:222
Seveau, Stephanie; Turner, Joanne; Gavrilin, Mikhail A et al. (2018) Checks and Balances between Autophagy and Inflammasomes during Infection. J Mol Biol 430:174-192
Michaux, Charlotte; Holmqvist, Erik; Vasicek, Erin et al. (2017) RNA target profiles direct the discovery of virulence functions for the cold-shock proteins CspC and CspE. Proc Natl Acad Sci U S A 114:6824-6829
Eguale, Tadesse; Birungi, Josephine; Asrat, Daniel et al. (2017) Genetic markers associated with resistance to beta-lactam and quinolone antimicrobials in non-typhoidal Salmonella isolates from humans and animals in central Ethiopia. Antimicrob Resist Infect Control 6:13
Gunn, John S; Bakaletz, Lauren O; Wozniak, Daniel J (2016) What's on the Outside Matters: The Role of the Extracellular Polymeric Substance of Gram-negative Biofilms in Evading Host Immunity and as a Target for Therapeutic Intervention. J Biol Chem 291:12538-46
Eade, Colleen R; Hung, Chien-Che; Bullard, Brian et al. (2016) Bile Acids Function Synergistically To Repress Invasion Gene Expression in Salmonella by Destabilizing the Invasion Regulator HilD. Infect Immun 84:2198-2208
Adcox, Haley E; Vasicek, Erin M; Dwivedi, Varun et al. (2016) Salmonella Extracellular Matrix Components Influence Biofilm Formation and Gallbladder Colonization. Infect Immun 84:3243-3251
Marshall, Joanna M; Gunn, John S (2015) The O-Antigen Capsule of Salmonella enterica Serovar Typhimurium Facilitates Serum Resistance and Surface Expression of FliC. Infect Immun 83:3946-59