title: Lesions caused by natural infection with Streptococcus suis type 9 in weaned pigs.
abstract: In this paper we report on the spectrum and frequency of lesions observed in a prospective study of naturally occurring infections with Streptococcus suis type 9 (SS-9) in weaned pigs. SS-9 produced arthritis, meningitis, interstitial pneumonia, and endocarditis in 100%, 91%, 73%, and 42%, respectively, of pigs dying from the disease. The lesions were similar to those caused by S. suis type 2 (SS-2), however, SS-9 produced a different frequency of lesions. In SS-2 infections, bronchopneumonia is the most commonly observed lesion; meningitis, arthritis, and endocarditis are less frequently observed. Thus, SS-9 produced a different distribution of lesions from that reported for SS-2. Possible explanations for the differences found are discussed.
authors.affiliation: Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Vasconcelos
authors.forename: D M
authors.initials: DM
authors.lastname: Middleton
authors.forename: J M
authors.initials: JM
authors.lastname: Chirino-Trejo
mesh_terms: D000818:Animals; D001168:Arthritis / Q000473:pathology / Q000662:veterinary; D006331:Heart Diseases / Q000473:pathology / Q000662:veterinary; D008171:Lung Diseases / Q000473:pathology / Q000662:veterinary; D009422:Nervous System Diseases / Q000473:pathology / Q000662:veterinary; D011446:Prospective Studies; D013290:Streptococcal Infections / Q000473:pathology / Q000662:veterinary*; D017011:Streptococcus suis / Q000145:classification*; D013552:Swine; D013553:Swine Diseases / Q000473:pathology*; D014886:Weaning