# Generation and characterization of a large-scale transposon mutant library of Rickettsia parkeri

> **NIH NIH R61** · JOHNS HOPKINS UNIVERSITY · 2024 · $286,563

## Abstract

The order Rickettsiales includes arthropod-associated, obligate intracellular bacteria that cause
diseases in humans ranging from relatively mild to potentially fatal. A mechanistic understanding
of growth and pathogenesis of rickettsial pathogens would potentiate therapeutic strategies to
control rickettsial disease. However, because of their obligate intracellular lifestyle and
consequent challenges in culturing and genetically manipulating these species, our
understanding of fundamental aspects of rickettsial biology is limited. Within the Rickettsia
genus, the Spotted Fever Group (SFG) includes tick-borne human pathogens that cause
diseases ranging from mild to life-threatening. Among the SFG bacteria, R. parkeri causes a
relatively mild disease and presents a tractable model for probing the biology of this group. In
the past, research leveraging a relatively small collection of transposon mutants of R. parkeri
has yielded important insights into Rickettsia pathogenesis and host interactions. Here, we
propose to expand the genetic toolkit available to study R. parkeri, generating a large-scale
transposon mutant library of R. parkeri in the R61 phase of this project and using it to gain
mechanistic insights into rickettsial growth and division in the R33 phase. In Aim 1, we will
develop and validate plasmid constructs for (1) generating transposon mutants of R. parkeri with
desired characteristics and (2) expressing genes of interest with and without tags in R. parkeri.
In Aim 2, we will generate, map, and organize a library of ~2000 transposon mutants of R.
parkeri. In the R33 phase, we will perform global analysis of growth kinetics and cell morphology
of all mutants in the transposon library in Aim 3. In Aim 4, we will leverage insights from
morphology screening to identify and characterize candidate factors that are important for
peptidoglycan cell wall hydrolysis during R. parkeri cell division. Completion of this project will
generate important genetic resources for the study of all aspects of R. parkeri biology and will
provide foundational knowledge about growth and cell division in an important tick-borne,
obligate intracellular pathogen that may aid in the design of new antibacterial therapeutic
approaches.

## Key facts

- **NIH application ID:** 10786317
- **Project number:** 1R61AI179998-01
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Erin D Goley
- **Activity code:** R61 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $286,563
- **Award type:** 1
- **Project period:** 2024-01-02 → 2026-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10786317

## Citation

> US National Institutes of Health, RePORTER application 10786317, Generation and characterization of a large-scale transposon mutant library of Rickettsia parkeri (1R61AI179998-01). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10786317. Licensed CC0.

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