TY - JOUR
T1 - Identification of virulent Capnocytophaga canimorsus isolates by capsular typing
AU - Hess, Estelle
AU - Renzi, Francesco
AU - Koudad, Dunia
AU - Dol, Mélanie
AU - Cornelis, Guy
N1 - Funding Information:
We thank E. Depiereux for his assistance for the statistical analysis, and K. Hack and F. Lauber (University of Namur) for stimulating discussions. The LABGeM (CEA/IG/Genoscope and CNRS UMR8030) and the France Génomique National infrastructure (funded as part of Investissement d'Avenir program managed by the Agence Nationale pour la Recherche, contract ANR-10-INBS-09) are acknowledged for support within the MicroScope annotation platform (30). This work was financed by grant SOC 1510582 from the Walloon Region and advanced grant 293605-CAPCAN from the European Research Council to G.R.C. We declare no conflicts of interest.
Publisher Copyright:
© 2017 Hess et al.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Capnocytophaga canimorsus is a dog oral commensal that causes rare but severe infections in humans. C. canimorsus was recently shown to be endowed with a capsular polysaccharide implicated in resistance to the innate immune system of the host. Here, we developed the first C. canimorsus capsular 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.
AB - Capnocytophaga canimorsus is a dog oral commensal that causes rare but severe infections in humans. C. canimorsus was recently shown to be endowed with a capsular polysaccharide implicated in resistance to the innate immune system of the host. Here, we developed the first C. canimorsus capsular 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.
KW - Capsular polysaccharide
KW - ELISA
KW - PCR
KW - Septicemia
KW - Serotyping scheme
KW - Western blot
KW - Gram-Negative Bacterial Infections/microbiology
KW - Humans
KW - Polysaccharides, Bacterial/analysis
KW - Capnocytophaga/classification
KW - Bacterial Typing Techniques/methods
KW - Animals
KW - Virulence Factors/analysis
KW - Dogs
KW - Serotyping/methods
UR - http://www.scopus.com/inward/record.url?scp=85019539497&partnerID=8YFLogxK
U2 - 10.1128/JCM.00249-17
DO - 10.1128/JCM.00249-17
M3 - Article
SN - 0095-1137
VL - 55
SP - 1902
EP - 1914
JO - Journal of clinical microbiology
JF - Journal of clinical microbiology
IS - 6
ER -