Production of suilysin, the thiol-activated haemolysin of Streptococcus suis, by field isolates from diseased pigs

摘要

STREPTOCOCCUS suis is a major cause of a contagious disease in pigs, which is characterised by arthritis, septicaemia, meningitis, pericarditis, endocarditis, polyserositis and pneumonia. So far, 29 capsular types of S suis have been identified and, worldwide, type 2 is most frequently isolated from diseased pigs (Higgins and Gottschalk 1990, Higgins and others 1992, Estoepangestie and Flores and others 1993, Hampson and others 1993, Lammler 1993). Little is known about the pathogenesis, virulence factors, or protective antigens of S suis. Whole cell vaccines seem to induce protection in pigs against homologous challenge (Holt and others 1990). However, the protection induced by whole-cell vaccines is probably type specific (Kebebe and others 1990),implying that such vaccines should contain many serotypes if broad protection is desired. Recently, we reported on the identification, purification and characterisation of a thiol-activated haemolysin designated suilysin, of S suis serotype 2 (Jacobs and others 1994). Haemolytic activity in S suis culture supernatants was also recognised by Feder and others (1994) and Gottschalk and others (1994).