Bacterial Physiology and Metabolism Unit
Established in 2021
Ashley Groshong, Ph.D. (She/Her/Hers)
Chief, Bacterial Physiology and Metabolism Unit
Contact: For contact information, search the NIH Enterprise Directory.
Major Areas of Research
- Nutritional uptake of Borrelia burgdorferi within the mammalian host and tick vector environments
- Nutrients available to the spirochete during the enzootic cycle
- Modulation of gene expression in response to changes in the host and/or vector environments
Lyme disease is primarily caused by the host’s immune response to the presence of the spirochete, Borrelia burgdorferi. The bacterium is delivered by an Ixodes spp. tick and can disseminate throughout the host, persisting primarily within the skin. While the bacteria is quite efficient in mammalian infection, it is wholly dependent on nutrient acquisition from host environments (both mammal and tick) during its lifecycle. Dissecting and understanding the nutrient requirements and acquisition pathways will provide insight into potential therapeutic avenues that could be utilized in clinical cases or even environmental remediation.
These studies currently focus on B. burgdorferi’s amino acid acquisition pathway. The spirochete is unable to synthesize its own amino acids, however, it only encodes a few free amino acid transporters. Unlike other bacteria, B. burgdorferi is completely reliant upon a multicomponent peptide transporter to bring in the bulk of necessary amino acids. This discovery has prompted an investigation into peptide sources within the host and vector which sustains bacterial colonization throughout the enzootic cycle, specialized roles peptides and/or peptide uptake may play during infection and tick colonization, and supportive roles that the additional free amino acid transporters may play.
Ph.D., University of Arkansas for Medical Sciences
B.S., B.A., University of Arkansas at Little Rock
Dr. Groshong received a B.S. in Biology and a B.A. in Chemistry and English at the University of Arkansas at Little Rock. She began studying Borrelia burgdorferi and its virulence determinants during her Ph.D. in Microbiology and Immunology at the University of Arkansas for Medical Sciences. She completed a postdoctoral fellowship at the University of Connecticut Health Center where she studied B. burgdorferi gene regulation throughout the enzootic cycle and continued on as an Instructor of Basic Science, where she began developing her studies on amino acid acquisition by the spirochete.
Groshong AM, McLain MA, Radolf JD. Host-specific functional compartmentalization within the oligopeptide transporter during the Borrelia burgdorferi enzootic cycle. PLoS Pathog. 2021 Jan;17(1):e1009180.
Caimano MJ, Groshong AM, Belperron A, Mao J, Hawley KL, Luthra A, Graham DE, Earnhart CG, Marconi RT, Bockenstedt LK, Blevins JS, Radolf JD. The RpoS Gatekeeper in Borrelia burgdorferi: An Invariant Regulatory Scheme That Promotes Spirochete Persistence in Reservoir Hosts and Niche Diversity. Front Microbiol. 2019 Aug;10:1923.
Groshong AM, Dey A, Bezsonova I, Caimano MJ, Radolf JD. Peptide Uptake Is Essential for Borrelia burgdorferi Viability and Involves Structural and Regulatory Complexity of its Oligopeptide Transporter. mBio. 2017 Dec;8(6):e02047-17.
Groshong AM, Fortune DE, Moore BP, Spencer HJ, Skinner RA, Bellamy WT, Blevins JS. BB0238, a presumed tetratricopeptide repeat-containing protein, is required during Borrelia burgdorferi mammalian infection. Infect Immun. 2014 Oct;82(10):4292-306.
Groshong AM, Blevins JS. Insights into the biology of Borrelia burgdorferi gained through the application of molecular genetics. Adv Appl Microbiol. 2014;86:41-143.
Groshong AM, Gibbons NE, Yang XF, Blevins JS. Rrp2, a prokaryotic enhancer-like binding protein, is essential for viability of Borrelia burgdorferi. J Bacteriol. 2012 Jul;194(13):3336-42.