Development of a lipid-based method for fluorescent labeling of Coxiella burnetii

Authors

• B Cardona
• R Akhi
• N Moutsopoulos
• T Ikeuchi

Abstract

As the etiologic agent of Q fever, Coxiella burnetii is a Gram-negative bacterium with significant scientific and clinical relevance. Currently, Q-Vax is the only commercially available preventative vaccine, however due to severe local and systemic reactions, it is only approved in Australia. These adverse reactions are collectively referred to as post-vaccination hypersensitivity (PVH) responses and are a form of granulatomous type IV delayed hypersensitivity resulting in leukocyte localization and subsequent severe inflammation and abscess formation. Although the PVH response is somewhat understood from the host perspective, the mechanisms of vaccine and pathogen dissemination are poorly understood, which in turn, contributes to the elusivity of reaching a full understanding of mechanisms underlying vaccine efficacy and post-vaccination hypersensitivity reactions.
Given the lack of knowledge regarding both infection and vaccination dissemination kinetics as well as the difficulties associated with tracking the bacteria within host tissues, we are developing a method for the labeling of C. burnetii with fluorescent lipid dyes for use in future dissemination studies. Labeled C. burnetii exhibits detectable levels of fluorescence that appear to be long lasting and are unaffected by fixation methods. Completion of this project should allow for the tracking and visualization of C. burnetii dissemination within in vivo animal models for the first time in an easy and efficient manner. Insights into dissemination patterns will be essential to better understand Q fever pathogenesis and inform therapeutic and countermeasure development, especially with regards to the development of an improved vaccine candidate with decreased risk for severe PVH reactions.

Scientific Focus Area: Microbiology and Infectious Diseases

This page was last updated on Monday, September 25, 2023