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An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines
Published on: October 11, 2022
The science and fiction of emerging rickettsioses
1Infectious Disease Pathology Branch, Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. CPaddock@cdc.gov
Abstract:
As newly recognized rickettsial diseases and rickettsial pathogens increase in scope and magnitude, several elements related to the concept of emerging rickettsioses deserve consideration. Newly identified rickettsiae may be mildly pathogenic, or perhaps even nonpathogenic, and have little direct impact on human or animal health, yet nonetheless wield considerable influence on the epidemiology and ecology of historically recognized diseases. In this context "new" rickettsioses provide a lens through which "old" rickettsioses are more accurately represented. Predicting pathogen from nonpathogen is not an exact science, particularly as so few rickettsiae have been broadly accepted as nonpathogenic by contemporary rickettsiologists. However, various factors relating to specific physiologic requirements and molecular machinery of the particular rickettsia, as well as characteristics of its invertebrate host that either position or exclude the rickettsia from infecting a human host, must be considered. Close inspection of mild or atypical forms of historically recognized rickettsioses and a greater emphasis on culture- and molecular-based diagnostic techniques are the keys to identifying future rickettsial agents of disease.
Insights
Emerging rickettsial diseases require careful study. Understanding new rickettsiae, even nonpathogenic ones, is key to recognizing old diseases and identifying future threats.
Area of Science:
- Microbiology
- Infectious Diseases
- Epidemiology
Background:
- The landscape of rickettsial diseases is expanding with newly identified pathogens.
- These novel rickettsiae, even if not directly pathogenic, impact the understanding of existing rickettsioses.
- Distinguishing pathogenic from nonpathogenic rickettsiae presents challenges.
Purpose of the Study:
- To explore the significance of newly recognized rickettsiae in the context of emerging rickettsioses.
- To highlight factors influencing the pathogenicity and transmission of rickettsiae.
- To emphasize diagnostic approaches for identifying novel rickettsial agents.
Main Methods:
- Review of current understanding of rickettsial epidemiology and ecology.
- Analysis of factors determining rickettsial host specificity (invertebrate and human).
- Emphasis on culture- and molecular-based diagnostic techniques.
Main Results:
- Newly identified rickettsiae influence the epidemiology and ecology of established rickettsial diseases.
- Physiological and molecular characteristics of rickettsiae, along with invertebrate host factors, are crucial for human infection potential.
- Mild or atypical presentations of known rickettsioses are important clues.
Conclusions:
- Emerging rickettsioses necessitate a broader perspective, including potentially nonpathogenic strains.
- Understanding the interplay between rickettsiae, invertebrate hosts, and human hosts is vital.
- Advanced diagnostic methods are essential for the future identification of disease-causing rickettsial agents.
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