Molecular prevalence of Bartonella, Babesia, and hemotropic Mycoplasma species in dogs with hemangiosarcoma from across the United States

Abstract

Hemangiosarcoma (HSA), a locally invasive and highly metastatic endothelial cell neoplasm, accounts for two-thirds of all cardiac and splenic neoplasms in dogs. Bartonella spp. infection has been reported in association with neoplastic and non-neoplastic vasoproliferative lesions in animals and humans. The objective of this study was to determine the prevalence of Bartonella spp. in conjunction with two other hemotropic pathogens, Babesia spp. and hemotropic Mycoplasma spp., in tissues and blood samples from 110 dogs with histopathologically diagnosed HSA from throughout the United States. This was a retrospective, observational study using clinical specimens from 110 dogs with HSA banked by the biospecimen repository of the Canine Comparative Oncology and Genomics Consortium. Samples provided for this study from each dog included: fresh frozen HSA tumor tissue (available from n = 100 of the 110 dogs), fresh frozen non-tumor tissue (n = 104), and whole blood and serum samples (n = 108 and 107 respectively). Blood and tissues were tested by qPCR for Bartonella, hemotropic Mycoplasma, and Babesia spp. DNA; serum was tested for Bartonella spp. antibodies. Bartonella spp. DNA was amplified and sequenced from 73% of dogs with HSA (80/110). In contrast, hemotropic Mycoplasma spp. DNA was amplified from a significantly smaller proportion (5%, p<0.0001) and Babesia spp. DNA was not amplified from any dog. Of the 100 HSA tumor samples submitted, 34% were Bartonella PCR positive (32% of splenic tumors, 57% of cardiac tumors, and 17% of other tumor locations). Of 104 non-tumor tissues, 63% were Bartonella PCR positive (56% of spleen samples, 93% of cardiac samples, and 63% of skin/subcutaneous samples). Of dogs with Bartonella positive HSA tumor, 76% were also positive in non-tumor tissue. Bartonella spp. DNA was not PCR amplified from whole blood. This study documented a high prevalence of Bartonella spp. DNA in dogs with HSA from geographically diverse regions of the United States. While 73%

Hemangiosarcoma Cells Promote Conserved Host-Derived Hematopoietic Expansion

“…A recent study reported an association between Bartonella spp and canine hemangiosarcoma. 38 Ten of 24 dogs tested in our study had detectable Bartonella spp sequences, although these were present in low abundance ( Table S3 ). Furthermore, four of the samples contained only sequences from B. bacilliformis, B. grahamii, or B. tribocorum, which infect humans and rats, respectively, and none of which is known to infect dogs as a primary or accidental host.…”

Protein regulation strategies of the mouse spleen in response to Babesia microti infection

“…Downregulation of ILF2 expression levels has been shown to inhibit cell proliferation [ 37 ], whereas downregulation of IFL3 expression, in addition to inhibition of cell proliferation, also inhibits cell migration and invasion and promotes cell apoptosis [ 38 ]. Some parasites such as Babesia , Plasmodium and Leishmania can cause unlimited cell proliferation after infecting hosts to eventually cause diseases in hosts [ 39 , 40 ]. This study showed that after B. microti infection in mice, the expression levels of ILF2 and IFL3 in the spleen were downregulated; notably, the expression levels were downregulated to the lowest levels at 11 days.…”

Exposure of Domestic Cats to Three Zoonotic Bartonella Species in the United States

“…antigens was less than 3% in 15,451 diagnostic sera submitted by veterinarians suspecting infection with a vector-borne pathogen further supports IFA specificity when testing dogs [ 30 ]. Regrettably, Bartonella IFA sensitivity is poor when testing dogs with PCR-confirmed infections [ 41 , 42 ]. Thus, epidemiological studies using dog sera should have excellent specificity, but will underestimate exposure among dogs regionally.…”