title: Evaluation on the pathogenicity of Erysipelothrix tonsillarum for pigs by immunosuppression with cyclophosphamide or dexamethasone.
abstract: The pathogenicity of Erysipelothrix tonsillarum was evaluated in pigs immunosuppressed with cyclophosphamide (CY) or dexamethasone (DM). Animals were treated with 15 mg/kg CY (n=8, five injections), 1 mg/kg DM (n=8, nine injections) or left untreated (n=8). On the fifth day after the beginning of drug treatments, swine were inoculated with one of two E. tonsillarum serovar 7 strains (approximately 10(6) CFU per pig). In the CY-treated group, both circulating neutrophil and lymphocyte counts decreased, whereas in the DM-treated group, lymphocyte counts decreased but neutrophil counts increased. During the observation period, none of the CY- or DM-treated pigs developed clinical signs or gross lesions, as well as non-treated pigs. Growth agglutination antibody titres in all pigs remained unchanged. Our findings indicate that E. tonsillarum strains are avirulent for swine, regardless of immune status.
authors.affiliation: National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, 1-15-1 Tokura, Kokubunji, Tokyo 185-8511, Japan. k-harada@nvlu.ac.jp
authors.forename: Kazuki
authors.initials: K
authors.lastname: Harada
authors.forename: Masatake
authors.initials: M
authors.lastname: Muramatsu
authors.forename: Shoko
authors.initials: S
authors.lastname: Suzuki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tamura
authors.forename: Takuo
authors.initials: T
authors.lastname: Sawada
authors.forename: Toshio
authors.initials: T
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D003520:Cyclophosphamide / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology*; D004888:Erysipelothrix / Q000145:classification / Q000472:pathogenicity*; D004889:Erysipelothrix Infections / Q000276:immunology / Q000382:microbiology*; D016867:Immunocompromised Host; D007166:Immunosuppressive Agents / Q000494:pharmacology; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology*
chemical_list: D000907:Antibodies, Bacterial; D007166:Immunosuppressive Agents; D003907:Dexamethasone; D003520:Cyclophosphamide