Research Update Mid-year 3 CHF 02519: Prevalence of Bartonella spp. Infection in Dogs with Cardiac and Splenic Hemangiosarcomas Within and Between Geographic Locations

We are on track to accomplish all of our aims for this study. We were able to obtain the initial set of samples on April 26, 2018 so we had a short delay in starting this study. We have now completed all Year I study aims, with the exception of immunohistochemistry and FISH localization of Bartonella organisms within various cell types. An unanticipated complication arose that the mouse monoclonal antibody was no longer being made commercially. B. henselae specific FISH probes have been designed and validation of FISH probes are in-progress. IHC is also in- progress. All qPCR and ddPCR have been completed at this time and samples are waiting for FISH and IHC analysis.

As reported above, we have published a manuscript to the Journal of Clinical Microbiology, representing additional research from our AKC-CHF study #02287, which allowed us to define the Western Blotting (WB) criteria for serodiagnosis of bartonellosis in dogs. That work required additional time and research effort to validate WB testing. We are very excited with the qPCR and ddPCR results obtained from the fresh frozen hemangiosarcoma tissues provided by the NIH-CCOGC. The results strongly support a role for Bartonella spp. in the etiopathogenesis of hemangiosarcoma in dogs. The regional study should provide additional insight as to the issue of potential causation. All three of the regions have identified, collected and shipped all necessary samples from their region. These samples have been tested by ddPCR, which has required months of validation. Validation of ddPCR is “In Press” in the Journal of Microbiological Methods. Because of the limitations on research activities at NCSU during the SARS-CoV2 pandemic, the testing and analysis of the study samples have been delayed. The NCSU College of Veterinary Medicine and the Intracellular Pathogens Research Laboratory have had suspended operations since March 2020. As of July 1, research operations are at limited capacity. Samples will continue to be processed, tested and analyzed as soon as possible given the constraints remaining in place to ensure staff safety. Even though we have had the down time we are still proposing to have this project complete by the end of the study on 1/31/2021.

Mid-Year-3 Research Update Dr. Breitschwerdt for investigation of potential causation of bartonella for hemangiosarcoma.