Immunologic characterization of the Bm05br protein using the Rhipicephalus linnaei (Audouin, 1826) species as a tick model.

The identification and characterization of tick proteins allow us to discover new physiological targets useful for the development of tick control methods. Bm05br (Brazil Rhipicephalus microplus protein 05) is a protein with unknown function identified in the saliva of R. microplus. Rs05br (Brazil Rhipicephalus sanguineus protein 05), a protein with 99 % similarity to Bm05br, was identified in Rhipicephalus linnaei egg, larval, and nymphal stages, as well as in adult saliva. To improve the knowledge about both proteins, immunological characterization was performed, including antigenicity analysis, vaccination trials, and artificial feeding. The sequence and antigenicity analysis of Bm05br and Rs05br proteins showed that R. linnaei could serve as a tick model for cross-protection studies. The recombinant Bm05br protein was immunogenic. Anti-Bm05br antibodies recognized the homologous protein Rs05br in different stages, organs, and in the saliva of R. linnaei. Although rBm05br did not induce a protective response against infestation in R. linnaei in this study, further experiments could be developed taking into account new formulations and animal models for vaccination. These results also serve as a reference for future research on the function of these proteins in R. microplus and R. linnaei physiology, as well as other species of the genus Rhipicephalus.

Streptococcus canis prostatitis and endocarditis with thromboembolism in a dog with sertoli cell tumour in a cryptic testis and prostatic squamous metaplasia.

We describe an unusual case of prostatitis caused by Streptococcus canis evolving to endocarditis and splenic, renal, and cerebral thromboembolism in a dog, associated with a Sertoli cell tumour in a cryptic testis and diffuse prostatic squamous metaplasia. A nine-year-old, intact male, mixed-breed dog was presented to a veterinary teaching hospital with abdominal pain and prostration. Physical examination and abdominal ultrasonography revealed an atrophic right testicle located in the subcutaneous tissue. The left testicle was in the abdominal cavity with increased dimensions and irregular contours. Complete blood count analysis showed marked neutrophilic leukocytosis and thrombocytopenia. After clinical worsening, euthanasia was performed, and the dog was submitted to post-mortem examination. The main gross findings included testicular malposition with one cryptic and one ectopic testis, enlarged prostate with purulent content, distension of the urinary bladder with cloudy urine, vegetative valvular endocarditis in the mitral valve, and spleen and renal infarcts. Histological examination showed a Sertoli cell tumour in the abdominal testis, diffuse prostatic squamous metaplasia with marked keratinization associated with bacterial prostatitis, fibrinonecrotic cystitis, bacterial endocarditis with marked myxomatous degeneration in the mitral valve, and splenic, renal, and cerebral thromboembolism. Microbiological analysis identified Streptococcus canis in the prostate and mitral valve. Sertoli cell tumour of cryptic testis increases oestrogen production and leads to squamous metaplasia of the prostate, which should be considered as predisposing factors for ascending S. canis infection from the urogenital tract to the prostate. Then, haematogenous spread of S. canis from the prostate to mitral valve cause endocarditis and subsequent thromboembolism and infarcts, all decisive to poor prognosis in this case.