Rickettsiae of indeterminate pathogenicity are widely associated with ticks. The presence of these endosymbionts can confound a One Health approach to combatting tick-borne diseases. Genomic analyses of symbiotic rickettsiae have revealed that they harbor mutations in gene coding for proteins involved in rickettsial pathogenicity and motility. We have isolated and characterized two rickettsial symbionts-Rickettsia peacockii and R. buchneri-both from ticks using tick cell cultures. To better track these enigmatic rickettsiae in ticks and at the tick-mammal interface we transformed the rickettsiae to express fluorescent proteins using shuttle vectors based on rickettsial plasmids or a transposition system driving insertional mutagenesis. Fluorescent protein expressing R. buchneri and R. peacockii will enable us to elucidate their interactions with tick and mammalian cells, and track their location and movement within individual cells, vector ticks, and host animals.
Bibliographical noteFunding Information:
This research was supported by National Institutes of Health grants R01 AI49424 and R01 AI081690 to U. G. M. (http://www.grants.nih.gov/grants/oer.htm). The funders had no role in study design, data collection, and analysis; decision to publish; or preparation of the manuscript. We thank Gerald Baldridge and Yumi Kumagai and Rod Felsheim for assistance in the R. peacockii research.
- Green fluorescent protein
- Himar 1 transposition
- MCherry fluorescent protein
- Rickettsia buchneri
- Rickettsia peacockii
- Shuttle vector