Related Experiment Videos
Attempted mechanical transfer of Ehrlichia risticii by tabanids (Diptera: Tabanidae)
J F Levine1, M G Levy, W L Nicholson
1Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606.
Abstract:
The ability of tabanid mouthparts to retain and to transfer mechanically Ehrlichia risticii Holland, Weiss, Burgdorfer, Cole & Kakoma was evaluated by feeding flies on infected and noninfected mice and on capillary tubes containing infected cells and cell-free medium. Flies representing two genera and 29 species were collected at equine boarding stables, farms, and along riding trails in Wake, Johnston, and Duplin counties in North Carolina for the feeding trials. Two species, Tabanus fulvulus Wiedemann and T. pallidescens Philip, fed on mice but failed to transfer the pathogen from infected to susceptible mice. Chrysops vittatus Wiedemann, Tabanus americanus Forster, and T. sulcifrons Macquart transferred E. risticii-infected cells from capillary tubes containing infected cells in medium to tubes containing medium. These studies document that E. risticii-infected cells can be retained on mouthparts and potentially transferred by tabanids.
Insights
Tabanid flies can retain Ehrlichia risticii-infected cells on their mouthparts. Some species may mechanically transfer these cells, potentially aiding in Ehrlichia (Ehrlichia risticii) transmission.
Area of Science:
- Veterinary Entomology
- Infectious Disease Transmission
- Medical Entomology
Background:
- Ehrlichia risticii is an important equine pathogen causing Potomac horse fever.
- The role of biting flies, such as tabanids, in the mechanical transmission of Ehrlichia risticii remains incompletely understood.
Purpose of the Study:
- To evaluate the capacity of tabanid mouthparts to retain and mechanically transfer Ehrlichia risticii.
- To identify tabanid species capable of retaining and potentially transmitting Ehrlichia risticii.
Main Methods:
- Feeding trials were conducted using 29 tabanid species collected from North Carolina.
- Flies were fed on infected mice and capillary tubes containing Ehrlichia risticii-infected cells or cell-free medium.
- Mouthpart retention and transfer of infected cells were assessed.
Main Results:
- Two Tabanus species (T. fulvulus, T. pallidescens) fed on infected mice but did not transfer the pathogen.
- Three species (Chrysops vittatus, Tabanus americanus, T. sulcifrons) successfully transferred Ehrlichia risticii-infected cells from capillary tubes.
- These findings demonstrate that infected cells can be retained on tabanid mouthparts.
Conclusions:
- Certain tabanid species possess the ability to retain Ehrlichia risticii-infected cells on their mouthparts.
- Mechanical transmission of Ehrlichia risticii by tabanids is plausible, highlighting their potential role in disease ecology.
- Further research is warranted to confirm in-field transmission dynamics.