Travis John Bourret, PhD
Associate Professor
Medical Microbiology and Immunology
Contact
School of Medicine
Med Microbiology & Immunology
Medical Microbiology and Immunology (Doctorate)
Medical Microbiology and Immunology (Master of Science)
Graduate School
CRISS I - Criss 1 - 521
Travis John Bourret, PhD
Associate Professor
Medical Microbiology and Immunology
Examples of the most recent publications can be obtained from this PubMed link.
Research Focus
Vector-borne diseases inflict significant morbidity and mortality worldwide, accounting for over 1/6 of infectious diseases cases in humans. Hematophagous arthropods, including hard-bodied (Ixodidae) and soft-bodied (Agarsidae) ticks, are capable of transmitting a wide variety of viral, bacterial, and protozoan pathogens. My laboratory is interested in the host-pathogen interface of Borrelia burgdorferi, the etiologic agent of Lyme disease, with its arthropod vector, the blacklegged tick Ixodes scapularis. As it cycles between its mammalian and tick hosts, B. burgdorferi encounters diverse environmental stresses including shifts in pH, temperature, nutrient availability, as well as immune defenses that include reactive oxygen species (ROS) and reactive nitrogen species (RNS). Many hematophagous arthropods, including Ixodid ticks, generate ROS and RNS in both salivary glands and midguts during blood meal acquisition, suggesting that tick-borne pathogens like B. burgdorferi face sustained exposure to oxidative and nitrosative stresses while in their arthropod hosts. Currently, it is unclear what effect ROS and RNS have on the ability of B. burgdorferi to complete its infectious cycle.
B. burgdorferi is of particular interest for studying the biological effects of ROS and RNS, as it lacks detectable concentrations of intracellular iron, and does not appear to encode proteins with iron-containing moieties (i.e., Fe-S clusters and cytochromes), which are prominent targets of ROS and RNS in many organisms. As such, B. burgdorferi has a limited potential for the production of harmful hydroxyl radicals (?OH) arising from iron-mediated Fenton chemistry, which combined with its limited arsenal of antioxidant defenses may explain why B. burgdorferi displays robust resistance to ROS-induced cytotoxicity. In contrast, B. burgdorferi is highly susceptible to the cytotoxic effects of RNS produced in vitro, which is associated with extensive RNS-dependent modifications (i.e. S-nitrosylation or oxidation) to free and zinc-bound cysteine thiols. Therefore, the major focuses of my laboratory are to:
1) Determine the effects of ROS and RNS produced by I. scapularisi ticks on the acquisition, colonization, and transmission of B. burgdorferi using the mouse-tick model of infection.
2) Study the redox proteome of B. burgdorferi by identifying proteins that are susceptible to oxidation or S-nitrosylation, and characterize the effects of such modifications on protein function, cell physiology, gene expression, and the overall virulence of B. burgdorferi.
Investigation of the host-pathogen interface, including characterizing the role of ROS and RNS on the infectious cycle of B. burgdorferi, may aid in efforts to develop therapeutic interventions or prophylactic measures to limit Lyme disease and other tick-borne illnesses.
Department
Med. Microbiology & Immunology
Position
Associate Professor
Books
- Bourret Travis, The PhoPQ two-component regulatory system: At the crossroads of nitrosative stress and Salmonella pathogenesis 2008
Publications
- Frontiers in cellular and infection microbiology
Richards Crystal L., Editorial: Host-pathogen interactions: the metabolic crossroads
13, p. 1212051 - 1212051 2023 - Zoonoses and public health
Hamik Jeff, Detection of Borrelia burgdorferi infected Ixodes scapularis (Acari: Ixodidae) associated with local Lyme disease transmission in Nebraska, USA, 2021 2023 - Journal of Visualized Experiments
Boyle William K., Essential Components of Borreliella (Borrelia) burgdorferi In Vitro Transcription Assays
2022:185 2022 - PLoS pathogens
Boyle William K., DksA-dependent regulation of RpoS contributes to Borrelia burgdorferi tick-borne transmission and mammalian infectivity
17:2 2021 - Current Issues in Molecular Biology
Samuels D. Scott, Gene regulation and transcriptomics
42, p. 223 - 266 2021 - Scientific Reports
Boyle William K., Establishment of an in vitro RNA polymerase transcription system
10:1 2020 - mSphere
Shikiya Ronald A., Failure to detect prion infectivity in ticks following prion-Infected blood meal
5:5 2020 - Journal of medical entomology
Luedtke Brandon E., Molecular Detection of Spotted Fever Group Rickettsiae (Rickettsiales
57:2, p. 519 - 523 2020 - Frontiers in cellular and infection microbiology
Jackson-Litteken Clay D., Assessing the Contribution of an HtrA Family Serine Protease During Borrelia turicatae Mammalian Infection
9 2019 - Journal of Visualized Experiments
Shaw Jeff A., Digital PCR-based competitive index for high-throughput analysis of fitness in Salmonella
2019:147 2019 - Cellular Microbiology
Bourret Travis J., The relapsing fever spirochete Borrelia turicatae persists in the highly oxidative environment of its soft-bodied tick vector
21:2 2019 - Journal of bacteriology
Boyle William K., DksA controls the response of the lyme disease spirochete borrelia burgdorferi to starvation
201:4 2019 - Journal of Biological Chemistry
Shaw Jeff A., Salmonella enterica serovar Typhimurium has three transketolase enzymes contributing to the pentose phosphate pathway
293:29, p. 11271 - 11282 2018 - Scientific Reports
Bourret Travis J., Magnesium homeostasis protects Salmonella against nitrooxidative stress
7:1 2017 - Journal of medical entomology
Jacques B. J., Role of Fly Cleaning Behavior on Carriage of Escherichia coli and Pseudomonas aeruginosa
54:6, p. 1712 - 1717 2017 - Nature Microbiology
Marroquin-Guzman M., The Magnaporthe Oryzae Nitrooxidative Stress Response Suppresses Rice Innate Immunity during Blast Disease
2 2017 - Frontiers in Microbiology
Bourret Travis John, The Nucleotide Excision Repair Pathway Protects Borrelia Burgdorferi from Nitrosative Stress in Ixodes Scapularis Ticks
7, p. (13 pages) 2016 - Husain Maroof, Redox sensor SsrB Cys²â°Â³ enhances Salmonella fitness against nitric oxide generated in the host immune response to oral infection 2015
- PloS one
Troxel Bryan, Pyruvate protects pathogenic spirochetes from H2O2 killing
9:1 2014 - Molecular Microbiology
Bourret Travis J., Nitrosative damage to free and zinc-bound cysteine thiols underlies nitric oxide toxicity in wild-type Borrelia burgdorferi
81:1, p. 259 - 273 2011 - Journal of Biological Chemistry
Henard Calvin A., Control of redox balance by the stringent response regulatory protein promotes antioxidant defenses of Salmonella
285:47, p. 36785 - 36793 2010 - Proceedings of the National Academy of Sciences of the United States of America
Husain Maroof, Redox sensor SsrB Cys203 enhances Salmonella fitness against nitric oxide generated in the host immune response to oral infection
107:32, p. 14396 - 14401 2010 - Infection and Immunity
Bourret Travis J., Codependent and independent effects of nitric oxide-mediated suppression of PhoPQ and Salmonella pathogenicity island 2 on intracellular Salmonella enterica serovar Typhimurium survival
77:11, p. 5107 - 5115 2009 - Journal of Biological Chemistry
Husain Maroof, Nitric oxide evokes an adaptive response to oxidative stress by arresting respiration
283:12, p. 7682 - 7689 2008 - PloS one
Bourret Travis J., Nitric oxide antagonizes the acid tolerance response that protects Salmonella against innate gastric defenses
3:3 2008 - Immunobiology
McCollister Bruce D., N2O3 enhances the nitrosative potential of IFNγ-primed macrophages in response to Salmonella
212:9-10, p. 759 - 769 2008 - Nitric oxide
Husain Maroof, O02. Accumulation of NADH following the NO-mediated inhibition of respiration stimulates adaptive response to oxidative stress
14:4, p. 1 - 1 2006 - Journal of Experimental Medicine
McCollister Bruce D., Repression of SPI2 transcription by nitric oxide-producing, IFNγ-activated macrophages promotes maturation of Salmonella phagosomes
202:5, p. 625 - 635 2005
Presentations
- Poster Presentation, "Characterization of the bb0168-encoded DnaK Suppressor Protein of Borrelia burgdorferi". Gordon Research Conference on the Biology of Spirochetes, January 16 - 20, 2016, Ventura, CA 2016
- Rickettsia rickettsii prevalence in Dermacentor varabilis in Dawson County, NE. Estrella Monrroy, Parth Chaudhari, Julie Shaffer, Travis Bourret. Annual Meeting of the Nebraska Academy of Sciences, Lincoln, NE 2015
- Comparison of infectious Ehrlichia, Rickettsia, and Anaplasma species of bacteria in American dog ticks from upland and lowland areas of Dawson County. Madelyn Warren, Julie Shaffer, Travis Bourret. Annual Meeting of the Nebraska Academy of Sciences, Lincoln, NE 2015
- Prevalence of disease causing bacteria in Dermacentor varabilis ticks in Buffalo County, NE. Parth Chaudhari, Whitney Nelson, Julie Shaffer, Travis Bourret. Annual Meeting of the Nebraska Academy of Sciences, Lincoln, NE 2015
- Rickettsia rickettsii prevalence in Dermacentor varabilis in Dawson County, NE. Estrella Monrroy, Parth Chaudhari, Julie Shaffer, Travis Bourret. Annual Meeting of the Missouri Valley Branch of the American Society of Microbiology, Lincoln, NE 2015
- Prevalence of disease causing bacteria in Dermacentor varabilis ticks in Buffalo County, NE. Parth Chaudhari, Whitney Nelson, Julie Shaffer, Travis Bourret. Annual Meeting of the Missouri Valley Branch of the American Society of Microbiology, Lincoln, NE 2015
Other
Roles of Reactive Oxygen and Nitrogen Species on Vector Colonization by Tickborne Relapsing Fever Spirochetes
DksA-Dependent Regulation of the Borrelia burgdorferi RNA Polymerase
Metabolic Sensing by the Global Gene Regulatory Protein DksA in the Lyme Disease Spirochete Borrelia burgdorferi
Roles of Reactive Oxygen and Nitrogen Species on Vector Colonization by Tickborne Relapsing Fever Spirochetes
DksA-Dependent Regulation of the Borrelia burgdorferi RNA Polymerase
Metabolic Sensing by the Global Gene Regulatory Protein DksA in the Lyme Disease Spirochete Borrelia burgdorferi