Project Team
Edward B. Breitschwerdt, DVM, PhD, Professor of Medicine and Infectious Diseases at North Carolina State University College of Veterinary Medicine, Adjunct Professor of Medicine at Duke University Medical Center, Director of the Intracellular Pathogens Research Laboratory in the Institute for Comparative Medicine at North Carolina State University.
Ricardo G. Maggi, PhD, Research Professor, North Carolina State University College of Veterinary Medicine.
Project lead Dr. Ed Breitchwerstz
Project Summary:
To develop novel enrichment culture, serological, and visualization methods for the diagnosis of the parasite Babesia in people with a range of chronic symptoms, with emphasis on Babesia odocoilei. This is being accomplished via four specific aims:
I. Experiments to determine the optimal blood culture conditions for Babesia DNA detection in samples collected from people with a spectrum of cardiac, rheumatological and neurological disorders.
II. Experiments to determine the geographic distribution, molecular prevalence, and the infecting Babesia species using blood samples from study participants that were previously tested for vector-borne pathogen Bartonella.
III. Experiments to identify immunodominant proteins in Babesia odocoilei (potentially the predominant Babesia species infecting people in the USA) that can be used to establish a serological assay for this species.
IV. Experiments to develop novel imaging techniques that will facilitate visualization of Babesia odocoilei in blood, enrichment blood cultures, and tissues from infected individuals.
Babesia Divergens
Project Background:
Babesiosis is a disease caused by the microscopic parasite Babesia which infects red blood cells. Babesia symptoms in people vary from asymptomatic, to non-specific, or life-threatening hemolytic anemia, particularly in immunocompromised individuals. Babesia is also increasingly being identified in blood or tissue samples obtained from patients with a range of chronic diseases, suggesting activity of the parasite may be contributing to more forms of chronic illness than previously understood.
Project team lead Dr. Edward B. Breitschwerdt is a global expert in Babesia research and the study of other vector-transmitted pathogens such as Bartonella. In a recent case series, Dr. Breitschwerdt’s team found a high level of Babesia in tissue collected from the uterus of a woman with endometriosis. Another study by the team found Bartonella and Babesia in the brain tissue of a child with seizures, mycotoxin exposure and suspected Rasmussen’s encephalitis.
The team is working to improve enrichment blood culture methods for Babesia identification.
Historically, diagnosis of human babesiosis was primarily based on microbiological observation of Babesia visualized inside red blood cells. Unfortunately, these visualization methods have poor sensitivity, due to a low number of circulating infected red blood cells. The most important, successful, and frequently used method for diagnosis of Babesia infection in people is through molecular methods.
The project team has been able to develop and validate three highly specific and sensitive molecular methods for Babesia species detection in sick individuals. One assay is a genus level digital PCR (dPCR) assay that amplifies a conserved DNA region of the 18S rRNA gene.
However the methods needed to identify Babesia in sample collected from patients with chronic disease still require further iteration to achieve maximal accuracy. To fill this gap the project team is developing novel imaging techniques to facilitate visualization of Babesia odocoilei, including:
•Developing a reliable ELISA assay for diagnosing Babesia odocoilei infection in humans
•Optimizing a novel enrichment culture to amplify small amounts of Babesia from tissue or blood samples for more accurate detection.
Without the development of these novel methods, Babesia in samples can be easily missed, leading to subpar Babesia diagnostics and potential underestimates of how important the pathogen’s activity may be across a range of chronic conditions. In addition, the new methods will allow the team to assess the prevalence of different Babesia species (B. divergens, B. microti, B. odocoilei, and B. duncani) in banked samples collected from over 1400 individuals. These include blood, serum, and culture samples from people with a spectrum of cardiac, rheumatological and neurological disorders.