Project Categories: Tick-Borne Disease

Bartonella, a genus of gram-negative bacteria, are associated with a wide spectrum of life- threatening diseases in animals and humans. More than 40 Bartonella species have been reported to infect mammalian reservoir hosts, and infection often leads to chronic bacteremia. At least ten Bartonella species have been implicated in association with serious diseases in dogs, including endocarditis, hemangiosarcoma, myocarditis, peliosis hepatis, polyarthritis and vasculitis. Despite biomedical advances and ongoing research in the field of canine bartonelloses, currently available PCR, culture, and serological based assays lack sensitivity for diagnosis of bartonelloses. Dogs throughout the United States and much of the world are exposed to Bartonella species.

From a public health perspective there is an increased risk of direct and vector-borne transmission of Bartonella species from animals to humans. These factors justify the need for the ongoing development of a reliable serodiagnostic modality and ultimately an effective vaccine for prevention of bartonelloses in dogs.

We will employ In-Vivo Induced Antigen Technology (IVIAT) to identify Bartonella in-vivo induced antigens, which will allow us to evaluate their potential as diagnostic markers for canine bartonelloses. This proposed study will result in development of a novel and sensitive ELISA assay for diagnosing Bartonella infection in dogs and will provide insights into the development of effective vaccine candidates for preventing Bartonella infection.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2819

RESEARCHERS

Edward Breitschwerdt, DVM ; North Carolina State University
Amount: $10,000

Diagnosing vector-borne disease (VBD) in dogs can be difficult for a number of reasons. First, there are many different disease-causing agents that can be transmitted from ticks/fleas, and the clinical signs caused by these agents in dogs can overlap. Additionally, because ticks/fleas can harbor more than one agent at a time, multiple pathogens may be passed to a dog with a single vector bite, resulting in co-infections.

VBD infections can initially present with non-specific signs, such as fever, lethargy, vomiting, diarrhea, and/or respiratory signs. Severe cases can be associated with neurologic signs. These signs can be a diagnostic conundrum. While initial blood work can be helpful and suggest VBD, it does not determine the infecting agent.

This study will develop a comprehensive next generation sequencing panel to detect and identify major VBD agents known to cause disease in dogs and to aid in diagnosis of active infections. Additionally, through parallel sequencing with this method, this panel will incorporate testing for additional infectious diseases that may cause GI, respiratory, or neurologic signs in dogs. The comprehensive nature of this sequencing panel should be a useful tool for surveillance of infectious diseases in the canine population for rapid identification of VBD in dogs and protection of pet owners from such zoonotic diseases.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02553

RESEARCHERS

Rebecca Wilkes, DVM; Purdue University
Amount: $2,500 (May 2019) $7,500 (November 2019)

Bartonellosis, a zoonotic bacterial disease of worldwide distribution, is caused by approximately 10 different Bartonella species. Bartonella are transmitted to canines and humans by ticks, fleas, lice, mites, and sand flies. Dr. Breitschwerdt’s laboratory demonstrated the first evidence for Bartonella infections in dogs in 1993.

Bartonella species have been associated with an expanding spectrum of important disease manifestations including anemia, endocarditis, hepatitis, lymphadenitis, myocarditis, thrombocytopenia and vascular tumor-like lesions. Infections can be life-threatening. Due to a lack of sensitive and reliable diagnostic assays, definitive diagnosis of bartonellosis in dogs remains a significant problem. Because these bacteria invade cells and infect tissues throughout the body, this chronic intracellular infection is difficult to cure with currently used antibiotic regimens.

This study will develop improved serodiagnostic tests for bartonellosis in dogs. These assays can also be used for world-wide sero-epidemiological prevalence studies, and to establish early and accurate diagnosis. Dr. Breitschwerdt’s research group has described concurrent infection in dogs, their owners and veterinary workers; this allows for a One Health approach to this important emerging infectious disease.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02287

RESEARCHERS

Dr. Edward B Breitschwerdt, DVM
North Carolina State University
Amount: $3,000

Diagnostic tests based on the detection of DNA of infectious organisms from clinical samples have revolutionized veterinary medicine in the last decades. Currently, diagnostic panels for several tickborne organisms are available through universities and private laboratories in the USA and abroad. However, the vast majority of results from clinically ill dogs are negative for tick-borne diseases, which frustrates veterinarians and dog owners trying to reach a definitive diagnosis and improve treatment options.

These panels are based on the detection of previously known DNA sequences of each pathogen, with little room for detecting new organisms. Consequently, the current assays may suffer from “myopia”: a self-fulfilling effect that prevents the detection of new or emerging organisms.

Using an innovative approach, the investigators will employ next-generation sequencing (NGS) to overcome the limitations of current diagnostic technology. With NGS, the investigators can generate millions of individual gene sequencing reads from each clinical sample, allowing for the identification and characterization of multiple organisms from a single sample. Testing samples from dogs naturally exposed to tick-borne diseases, NGS will detect not only new organisms but also characterize genetic differences among known organisms.

The resulting dataset of a large number of DNA sequences of known tick-borne organisms and previously undetected organisms in naturally-infected dogs will support the development of diagnostic tools to simultaneously advance canine and human health.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02292

RESEARCHERS

Dr. Pedro Paul Diniz, DVM, PhD
Western University of Health Sciences
Amount: $3,000