Brady Spencer
Assistant Professor of Microbiology, Immunology, and Cancer Biology, Microbiology, Immunology, and Cancer Biology
Bio & Overview
The Spencer lab studies host-pathogen interactions of Gram-positive bacteria, focusing on the major neonatal pathobiont Group B Streptococcus (GBS). GBS can asymptomatically colonize the female genital tract, leading to transmission during pregnancy, and the neonatal GI tract, and both these niches serve as reservoirs for neonatal bacteremia and meningitis upon penetration of the blood-brain barrier. We are interested in how GBS factors promote colonization and systemic infection.
Specifically, we study the molecular mechanisms of the type VII secretion system (T7SS) in GBS and how its secreted proteins and toxins contribute to toxicity and inflammation during pathogenesis, as well as to mucosal colonization/niche establishment by outcompeting other bacteria and modulating the immune response. Our research is highly interdisciplinary, spanning pathogenesis, biochemistry, structural biology, immunology, reproductive and gastrointestinal biology, and the microbiome. We employ microbiological, molecular, cellular, biochemical, and immunological methods, as well as cellular and animal models, to examine the impact of the T7SS on GBS interactions with microbes and the host.
Academic Information
- Department
- Microbiology, Immunology, and Cancer Biology
Primary Education
- BS, Biochemistry and Molecular Biology, Harding University, 2012
- PhD, Microbiology, University of Alabama at Birmingham, 2017
Research Interests
Research Disciplines
- Biochemistry
- Immunology
- Infectious Diseases/Biodefense
- Microbiology
- Molecular Biology
- Neuroimmunology
Research Opportunities
- Biochemistry
- Cell Biology
- Immunology
- Infectious Diseases
- Microbiology
- Molecular Biology
- Neuroimmunology
PhD Programs
- Microbiology
- Neuroscience
Selected Publications
2026
Spencer BL (2026). mSphere of Influence: Is asymptomatic colonization really silent? In press, mSphere.
Sol K, Joyce LR, Brady A, Spencer BL, Pawlikowski B, Derk J, Doran KS, Siegenthaler J (2026). Meningeal inflammation and arachnoid barrier breakdown in a mouse model of neonatal bacterial meningitis. In press, Cell Reports.
Wiafe-Kwakye CS, Glenn AE, Spencer BL. (2026). Type VIIb Secretion Systems in Lactobacillales: Insights from Streptococci and Enterococci. J Bacteriol. 2026 Aug 20;208(8):e0023626. doi: 10.1128/jb.00236-26.
2025
Joyce LR, Akbari MS, Nguyen DT, Spencer BL, McIver KS, Horswill AR, Doran KS, Keogh RA (2025). Global genome analysis identifies glycolipids and lipoteichoic acid alanylation as contributors to Group B streptococcal diabetic wound infection. Cell Rep. 2025 Nov 25;44(11):116510.doi: 10.1016/j.celrep.2025.116510. Epub 2025 Nov 4.
Spencer BL*, Nguyen DT, Marroquin SM, Gapin L, O'Brien RL, Doran KS (2025). Characterization of the Cellular Immune Response to Group B Streptococcal Vaginal Colonization. J Innate Immun. 2025 Oct 2;17(1):1-22. doi: 10.1159/000548044. *Co-corresponding author
Bhattacharya M, Spencer BL, Kwiecinski JM, Podkowik M, Putzel G, Pironti A, Shopsin B, Doran KS, Horswill AR (2025). Collagen binding adhesin restricts Staphylococcus aureus skin infection (2025). Nat. Comm, 2025 Nov 24:2024. doi: 10.1101/2024.11.01.621145.
Akbari MS, Joyce LR, Spencer BL, Brady A, McIver KS, Doran KS (2025). Identification of Glyoxalase A in Group B Streptococcus and its contribution to methylglyoxal tolerance and virulence. Infect Immun. 2025 Apr 8;93(4):e0054024. doi: 10.1128/iai.00540-24. Epub 2025 Feb 26.
2024
Job AM, Doran KS, Spencer BL* (2024). A group B streptococcal type VII-secreted LXG toxin mediates interbacterial competition and colonization of the murine female genital tract. mBio. Oct 16:e0208824. doi: 10.1128/mbio.02088-24. Epub 2024 Aug 27. *Co-corresponding author
Joyce, L. R., Kim, S., Spencer, B. L., Christensen, P. M., Palmer, K. L., Guan, Z., . . . Doran, K. S. (2024). Streptococcus agalactiae
glycolipids promote virulence by thwarting immune cell clearance. Science Advances, 10(22). doi:10.1126/sciadv.adn7848
2023
Spencer, B. L., Job, A. M., Robertson, C. M., Hameed, Z. A., Serchejian, C., Wiafe‐Kwakye, C. S., . . . Doran, K. S. (2023). Heterogeneity of the group B streptococcal type VII secretion system and influence on colonization of the female genital tract. Molecular Microbiology, 120(2), 258-275. doi:10.1111/mmi.15115
da Conceição Mendonça, J., Sobral Pena, J. M., dos Santos Macêdo, N., de Souza Rodrigues, D., de Oliveira, D. A., Spencer, B. L., . . . Nagao, P. E. (n.d.). Enhanced Vulnerability of Diabetic Mice to Hypervirulent Streptococcus agalactiae ST-17 Infection. Pathogens, 12(4), 580. doi:10.3390/pathogens12040580
Derk, J., Como, C. N., Jones, H. E., Joyce, L. R., Kim, S., Spencer, B. L., . . . Siegenthaler, J. A. (2023). Formation and function of the meningeal arachnoid barrier around the developing mouse brain. Developmental Cell, 58(8), 635-644.e4. doi:10.1016/j.devcel.2023.03.005
2022
Spencer, B. L., & Doran, K. S. (n.d.). Evolving understanding of the type VII secretion system in Gram-positive bacteria. PLOS Pathogens, 18(7), e1010680. doi:10.1371/journal.ppat.1010680
2021
Keogh, R. A., Spencer, B. L., Sorensen, H. M., Zapf, R. L., Briaud, P., Bonsall, A. E., . . . Carroll, R. K. (2021). Global Annotation, Expression Analysis, and Stability of Candidate sRNAs in Group B Streptococcus. mBio, 12(6). doi:10.1128/mbio.02803-21
Spencer, B. L., Tak, U., Mendonca, J. C., Nagao, P. E., Niederweis, M., & Doran, K. S. (2021). A type VII secretion system in Group B Streptococcus mediates cytotoxicity and virulence. PLOS PATHOGENS, 17(12). doi:10.1371/journal.ppat.1010121
Brissac, T., Martínez, E., Kruckow, K. L., Riegler, A. N., Ganaie, F., Im, H., . . . Orihuela, C. J. (2021). Capsule Promotes Intracellular Survival and Vascular Endothelial Cell Translocation during Invasive Pneumococcal Disease. mBio, 12(5). doi:10.1128/mbio.02516-21
Spencer, B. L., Doran, K. S., & Burcham, L. R. (2021). The Virtual Streptococcal Seminar Series and Trainee Symposium: Adaptations of a Research Community during the COVID-19 Pandemic. Journal of Microbiology & Biology Education, 22(1). doi:10.1128/jmbe.v22i1.2479
Spencer, B. L., Chatterjee, A., Duerkop, B. A., Baker, C. J., & Doran, K. S. (2021). Complete Genome Sequence of Neonatal Clinical Group B Streptococcal Isolate CJB111. Microbiology Resource Announcements, 10(2). doi:10.1128/mra.01268-20
2020
Burcham, L. R., Le Breton, Y., Radin, J. N., Spencer, B. L., Deng, L., Hiron, A., . . . Doran, K. S. (2020). Identification of Zinc-Dependent Mechanisms Used by Group B
Streptococcus
To Overcome Calprotectin-Mediated Stress. mBio, 11(6). doi:10.1128/mbio.02302-20
Alhajjar, N., Chatterjee, A., Spencer, B. L., Burcham, L. R., Willett, J. L. E., Dunny, G. M., . . . Doran, K. S. (2020). Genome-Wide Mutagenesis Identifies Factors Involved in Enterococcus faecalis Vaginal Adherence and Persistence. Infection and Immunity, 88(10). doi:10.1128/iai.00270-20
2019
Burcham, L. R., Spencer, B. L., Keeler, L. R., Runft, D. L., Patras, K. A., Neely, M. N., & Doran, K. S. (n.d.). Determinants of Group B streptococcal virulence potential amongst vaginal clinical isolates from pregnant women. PLOS ONE, 14(12), e0226699. doi:10.1371/journal.pone.0226699
Spencer, B. L., Deng, L., Patras, K. A., Burcham, Z. M., Sanches, G. F., Nagao, P. E., & Doran, K. S. (n.d.). Cas9 Contributes to Group B Streptococcal Colonization and Disease. Frontiers in Microbiology, 10. doi:10.3389/fmicb.2019.01930
Deng, L., Spencer, B. L., Holmes, J. A., Mu, R., Rego, S., Weston, T. A., . . . Doran, K. S. (n.d.). The Group B Streptococcal surface antigen I/II protein, BspC, interacts with host vimentin to promote adherence to brain endothelium and inflammation during the pathogenesis of meningitis. PLOS Pathogens, 15(6), e1007848. doi:10.1371/journal.ppat.1007848
2018
Geno, K. A., Spencer, B. L., Bae, S., & Nahm, M. H. (n.d.). Ficolin-2 binds to serotype 35B pneumococcus as it does to serotypes 11A and 31, and these serotypes cause more infections in older adults than in children. PLOS ONE, 13(12), e0209657. doi:10.1371/journal.pone.0209657
Deng, L., Mu, R., Weston, T. A., Spencer, B. L., Liles, R. P., & Doran, K. S. (2018). Characterization of a Two-Component System Transcriptional Regulator, LtdR, That Impacts Group B Streptococcal Colonization and Disease. Infection and Immunity, 86(7). doi:10.1128/iai.00822-17