title: Role of the capsular polysaccharide as a virulence factor for Streptococcus suis serotype 14.
abstract: Streptococcus suis is an important swine pathogen and a zoonotic agent causing meningitis and septicemia. Although serotype 2 is the most virulent type, serotype 14 is emerging, and understanding of its pathogenesis is limited. To study the role of the capsular polysaccharide (CPS) of serotype 14 as a virulence factor, we constructed knockout mutants devoid of either cps14B, a highly conserved regulatory gene, or neu14C, a gene coding for uridine diphospho-N-acetylglucosamine 2-epimerase, which is involved in sialic acid synthesis. The mutants showed total loss of the CPS with coagglutination assays and electron microscopy. Phagocytosis assays showed high susceptibility of mutant Δcps14B. An in vivo murine model was used to demonstrate attenuated virulence of this non-encapsulated mutant. Despite the difference in the CPS composition of different serotypes, this study has demonstrated for the first time that the CPS of a serotype other than 2 is also an important antiphagocytic factor and a critical virulence factor.
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: David
authors: D
authors: Roy
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: Jean-Philippe
authors: JP
authors: Auger
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: Mariela
authors: M
authors: Segura
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: Nahuel
authors: N
authors: Fittipaldi
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: Daisuke
authors: D
authors: Takamatsu
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: Masatoshi
authors: M
authors: Okura
authors: Groupe de recherche sur les maladies infectieuses du porc et Centre de recherche en infectiologie porcine et avicole, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec J2S 2M2 (Roy, Auger, Segura, Gottschalk); Public Health Ontario, Resources Road, Toronto, Ontario M9P 3T1 (Fittipaldi); Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Kannondai, Tsukuba, Ibaraki, 305-0856, Japan (Takamatsu, Okura); The United Graduate School of Veterinary Sciences, Gifu University, Yanagido, Gifu 501-1193, Japan (Takamatsu).
authors: Marcelo
authors: M
authors: Gottschalk
mesh_terms: D000818:Animals; D016667:Bacterial Capsules / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D008264:Macrophages; D051379:Mice; D009154:Mutation; D010587:Phagocytosis; D011135:Polysaccharides, Bacterial / Q000235:genetics / Q000378:metabolism*; D065288:Serogroup; D013290:Streptococcal Infections / Q000382:microbiology*; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D011135:Polysaccharides, Bacterial; D037521:Virulence Factors