# Conditional Null Mutants in the Study Essential Gene Products of Chlamydia

> **NIH NIH R21** · UNIVERSITY OF KENTUCKY · 2020 · $191,250

## Abstract

ABSTRACT
 Chlamydia trachomatis represents a significant health concern world-wide. A substantial
burden exists due to the prevalence and the combined health and socioeconomic impact of
acute and chronic disease. All Chlamydia species express a type III secretion system (T3SS),
and this mechanism likely contributes significantly to overall pathogenesis. Chlamydiae are
obligate intracellular parasites that undergo a complex developmental cycle, and this biology
has historically impeded rapid progress in understanding pathogenesis. The newly acquired
ability to inactivate chlamydial genes via insertion or deletion mutagenesis has greatly facilitated
characterization of virulence factors. Unfortunately, significant barriers remain in the application
of genetics in elucidating molecular mechanisms of virulence. For example, there is currently
no mechanism to generate null strains for gene products that are absolutely essential for
chlamydial propagation in cell culture. To this end, we have adapted the fluorescence-reported
allelic exchange mutagenesis technique to facilitate creation of conditional null strains in
essential genes. Preliminary data describing such a situation for a type III effector gene are
presented herein. We propose to validate and further develop our approach while revealing the
function of a highly important effector protein. At the end of these studies, we will have
established new approaches that will benefit the entire Chlamydia research community and
advance the understanding of how T3S manifests during chlamydial infection.

## Key facts

- **NIH application ID:** 9869848
- **Project number:** 5R21AI144648-02
- **Recipient organization:** UNIVERSITY OF KENTUCKY
- **Principal Investigator:** KENNETH A FIELDS
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $191,250
- **Award type:** 5
- **Project period:** 2019-02-11 → 2021-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9869848

## Citation

> US National Institutes of Health, RePORTER application 9869848, Conditional Null Mutants in the Study Essential Gene Products of Chlamydia (5R21AI144648-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9869848. Licensed CC0.

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