Specific-pathogen-free pigs as an animal model for studying Chlamydia trachomatis genital infection

The purpose of the present study was to evaluate pigs as a large-animal model for female genital infection with two Chlamydia trachomatis human serovar E strains. Sixteen-week-old specific-pathogen-free female pigs (gilts) were intravaginally infected with the trachoma type E reference strain Bour or the urogenital serovar E strain 468. Several conclusions can be drawn from our findings on the pathogenicity of a primary C. trachomatis genital infection in gilts. First of all, we demonstrated that the serovar E strains Bour and 468 could ascend in the genital tract of gilts. The serovar E strains could replicate in the superficial columnar cervical epithelium and in the superficial epithelial layer of the uterus, which are known to be the specific target sites for a C. trachomatis genital infection in women. Second, inflammation and pathology occurred at the replication sites. Third, the organisms could trigger a humoral immune response, as demonstrated by the presence of immunoglobulin M (IgM), IgG, and IgA in both serum and genital secretion samples. Our findings imply that the pig model might be useful for studying the pathology, pathogenesis, and immune response to a C. trachomatis infection of the genital system

Intracranial oligodendroglioma with optic nerve infiltration in a Labrador retriever

A seven-year-old neutered male Labrador retriever was presented with behavioral changes and reduced vision. Neurological examination revealed blindness of the left eye with a positive pupillary light reflex and a decreased mental status. Blood and cerebrospinal fluid analyses showed no abnormalities. MRI revealed a deviant area located in the thalamic, hypothalamic and caudate nuclear regions. Invasion of the left optic nerve was also observed. The dog was euthanized after 38 days of palliative treatment. Necropsy showed a non-encapsulated extruding white lardaceous mass, with a diameter of 2 cm, in the white matter, located in the ventral thalamic region near the chiasma opticum, which extended along the left optic nerve. Histologically, neoplastic cells had a “fried egg” appearance. Immunolabelling for glial fibrillary acidic protein demonstrated the presence of numerous reactive astrocytes. The tumor was diagnosed as a low grade (II) intracranial oligodendroglioma with infiltration of the optic nerve.</jats:p