Streptococcus suis type II-associated diseases in swine: observations of a one-year study.

Streptococcus suis type II was isolated from 170 pigs submitted to a veterinary diagnostic laboratory in Ontario, Canada, over a 1-year period. The most common disease condition with which the organism was identified was suppurative bronchopneumonia, usually secondary to enzootic pneumonia of pigs. The organism was also isolated in cases of pleuropneumonia, valvular endocarditis, arthritis, and vaginitis as well as from aborted fetuses. A condition characterized by neonatal disease and rapid death, usually within the first 24 hours of life, was identified in 23 pigs from 5 farms. Meningitis was identified in 15 weaned pigs from 8 farms. All S suis type II isolates tested for antimicrobial sensitivity were sensitive to penicillin and ampicillin. Most isolates were also sensitive to chloramphenicol and trimethoprim-sulfamethoxazole, but resistant to streptomycin and tetracycline. Accessions from which the organism was isolated were concentrated in the colder months of the year, with few or no isolates recorded in the summer months.