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Johanna B. Holm, PhD

Academic Title:

Assistant Professor

Primary Appointment:

Microbiology and Immunology

Additional Title:

Member, Institute for Genome Sciences Member, Center for Advanced Microbiome Research and Innovation

Phone (Primary):

410-706-7905

Education and Training

I received my Ph.D. from the University of Southern California, with specialized training in marine microbiome analyses. I pursued postdoctoral training in the laboratory of Dr. Jacques Ravel and then joined the faculty at the Institute for Genome Sciences and Department of Microbiology and Immunology at the University of Maryland School of Medicine. 

Biosketch

I am a microbial ecologist with deep expertise in characterizing the vaginal microbiome through multi-omics, bioinformatics, and experimental modeling. My research focuses on uncovering how microbial communities influence women’s reproductive health, particularly in the context of sexually transmitted infections (STIs) and bacterial vaginosis (BV). A central goal of my work is to define the microbial and molecular mechanisms by which cervicovaginal microbiota modulate host susceptibility to pathogens such as Chlamydia trachomatis, Mycoplasma genitalium, and Trichomonas vaginalis, as well as the persistent challenge of BV recurrence. Through NIH-funded training and faculty awards (F32-AI136400, K01-AI163413), I have contributed to and led the development of several widely used bioinformatic tools that enable high-resolution, taxonomic and functional analysis of vaginal microbial communities. These tools underpin my efforts to redefine clinical paradigms by replacing symptom-based diagnostics with metagenomic community state types (mgCSTs) that better predict infection risk and BV recurrence. My lab integrates taxonomic, functional, and host-response data and aims to validate mechanistic hypotheses using 3D organotypic models of the cervicovaginal epithelium.

The long-term goal of my laboratory is to uncover causal pathways linking the vaginal microbiome and host responses to infection outcomes and to translate these insights into predictive diagnostics and microbiome-informed, antibiotic-sparing interventions. By bridging computational discovery with mechanistic validation, my research aims to transform our understanding of mucosal pathogenesis and improve reproductive health outcomes globally.

Highlighted Publications

 

  1. Holm JB, France MT, Gajer P, Ma B, Brotman RM, Shardell M, Forney L, Ravel J.Integrating compositional and functional content to describe vaginal microbiomes in health and disease. Microbiome.2023 Nov 30;11(1):259.doi: 10.1186/s40168-023-01692-x.PubMed PMID: 38031142; PubMed Central PMCID: PMC10688475.
  2. Holm, JB, Carter, KA, Ravel, J, Brotman, RB.Lactobacillus iners and Genital Health: Molecular Clues to an Enigmatic Vaginal Species. Curr Infect Dis Rep (2023). https://doi.org/10.1007/s11908-023-00798-5. PMID: 37234911.
  3. Holm JB, Humphrys MS, Robinson CK, Settles ML, Ott S, Fu L, Yang H, Gajer P, He X, McComb E, Gravitt PE, Ghanem KG, Brotman RM, Ravel J. 2019. Ultrahigh-Throughput Multiplexing and Sequencing of >500-Base-Pair Amplicon Regions on the Illumina HiSeq 2500 Platform. mSystems 2019;4. PMID: 30801027.
  4. Ma B, France MT, Crabtree J, Holm JB, Humphrys MS, Brotman RM, Ravel J. A comprehensive non-redundant gene catalog reveals extensive within-community intraspecies diversity in the human vagina. Nat Communications. 2020 Feb 26;11(1):940. PMID: 32103005.
  5. Holm JB, France M, Ma B, McComb E, Robinson CK, Mehta A, Tallon LJ, Brotman RM, Ravel J. Comparative genome analysis of “Candidatus Lachnocurva vaginae”, formerly known as Bacterial Vaginosis Associated Bacteria – 1 (BVAB1), Frontiers Cellular and Infection Microbiology, 2020 Mar 31;10:117. PMID: 32296647, PMCID: PMC7136613.

 

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