title: Multiplication of Brucella canis in male reproductive organs and detection of autoantibody to spermatozoa in canine brucellosis.
abstract: Orchitis, epididymitis and prostatitis have been reported in male dogs infected with Brucella canis (B. canis), but the pathogenesis of infertility in male dogs has not been clarified yet. We examined localization of B. canis in the tissue of infected male reproductive organs and production of autoantibody to spermatozoa in male dogs by immunofluorescence and unlabeled antibody peroxidase-antiperoxidase (PAP) methods and electron microscopy. B. canis were found in the cytoplasm of macrophages and epithelial cells in testis, epididymis and prostate. Particularly in the prostate, B. canis multiplied in the cytoplasm of epithelial cells and emerged in the glandular lumen with destroyed epithelial cells. Head-to-head agglutination of spermatozoa was found in the semen, urine and epididymal duct with varying degrees of intensity among the infected dogs. Appearance of the spermagglutination began following the detection of B. canis in urine and semen, suggesting invasion of the organisms in male reproductive organs. In the sera from the dogs orally inoculated with B. canis, (Ig M), Ig G and Ig A anti-spermantibodies were detected in parallel with the appearance of the serum spermagglutinating activity. The heads of agglutinated spermatozoa in the epididymal duct and semen were coated with Ig A antibody, which is considered to be anti-spermautoantibody locally produced. The target of these circulating and local antibodies was acrosome of the dog spermatozoa and spermatids. It seems probable that multiplication of B. canis in epithelial cells is the direct cause of damage to the infected cells, and the damage acts as a trigger of the production of autoantibody to spermatozoa.
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000032:analysis*; D002002:Brucella / Q000166:cytology* / Q000276:immunology; D002006:Brucellosis / Q000150:complications / Q000276:immunology / Q000382:microbiology*; D002455:Cell Division; D004285:Dogs; D005455:Fluorescent Antibody Technique; D005837:Genitalia, Male / Q000382:microbiology*; D007124:Immunoenzyme Techniques; D007248:Infertility, Male / Q000209:etiology; D008297:Male; D013094:Spermatozoa / Q000276:immunology*
chemical_list: D001323:Autoantibodies