title: Identification of Virulent Capnocytophaga canimorsus Isolates by Capsular Typing.
abstract: Capnocytophaga canimorsusis a dog oral commensal that causes rare but severe infections in humans.C. canimorsuswas recently shown to be endowed with a capsular polysaccharide implicated in resistance to the innate immune system of the host. Here, we developed the firstC. canimorsuscapsular serotyping scheme. We describe nine different serovars (A to I), and this serotyping scheme allowed typing of 25/25 isolates from human infections but only 18/52 isolates from dog mouths, indicating that the repertoire of capsules in the species is vast. However, while only three serovars (A, B, and C) covered 88% of the human isolates tested (22/25), they covered only 7.7% of the dog isolates (4/52). Serovars A, B, and C were found 22.9-, 14.6-, and 4.2-fold more often, respectively, among human isolates than among dog isolates, with no geographical bias, implying that isolates endowed with these three capsular types are more virulent for humans than other isolates. Capsular serotyping would thus allow identification of virulent isolates in dogs, which could contribute to the prevention of these infections. To this end, we developed a PCR typing method based on the amplification of specific capsular genes.
authors.affiliation: Unité de Recherche en Biologie des Microorganismes, Université de Namur, Namur, Belgium.
authors.forename: Estelle
authors.initials: E
authors.lastname: Hess
authors.affiliation: Unité de Recherche en Biologie des Microorganismes, Université de Namur, Namur, Belgium.
authors.forename: Francesco
authors.initials: F
authors.lastname: Renzi
authors.affiliation: Unité de Recherche en Biologie des Microorganismes, Université de Namur, Namur, Belgium.
authors.forename: Dunia
authors.initials: D
authors.lastname: Koudad
authors.affiliation: Unité de Recherche en Biologie des Microorganismes, Université de Namur, Namur, Belgium.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Dol
authors.affiliation: Unité de Recherche en Biologie des Microorganismes, Université de Namur, Namur, Belgium guy.cornelis@unamur.be.
authors.forename: Guy R
authors.initials: GR
authors.lastname: Cornelis
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques / Q000379:methods*; D002206:Capnocytophaga / Q000145:classification* / Q000302:isolation & purification; D004285:Dogs; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology* / Q000662:veterinary*; D006801:Humans; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D012703:Serotyping / Q000379:methods*; D037521:Virulence Factors / Q000032:analysis*
chemical_list: D011135:Polysaccharides, Bacterial; D037521:Virulence Factors
keywords: ELISA; PCR; Western blot; capsular polysaccharide; septicemia; serotyping scheme