title: D-alanylation of lipoteichoic acid contributes to the virulence of Streptococcus suis.
abstract: We generated by allelic replacement a DeltadltA mutant of a virulent Streptococcus suis serotype 2 field strain and evaluated the contribution of lipoteichoic acid (LTA) d-alanylation to the virulence traits of this swine pathogen and zoonotic agent. The absence of LTA D-alanylation resulted in increased susceptibility to the action of cationic antimicrobial peptides. In addition, and in contrast to the wild-type strain, the DeltadltA mutant was efficiently killed by porcine neutrophils and showed diminished adherence to and invasion of porcine brain microvascular endothelial cells. Finally, the DeltadltA mutant was attenuated in both the CD1 mouse and porcine models of infection, probably reflecting a decreased ability to escape immune clearance mechanisms and an impaired capacity to move across host barriers. The results of this study suggest that LTA D-alanylation is an important factor in S. suis virulence.
authors.affiliation: Groupe de Recherche sur les Maladies Infectieuses du Porc and Centre de Recherche en Infectiologie Porcine, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada.
authors.forename: Nahuel
authors.initials: N
authors.lastname: Fittipaldi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sekizaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takamatsu
authors.forename: Josée
authors.initials: J
authors.lastname: Harel
authors.forename: María de la Cruz
authors.initials: Mde L
authors.lastname: Domínguez-Punaro
authors.forename: Sonja
authors.initials: S
authors.lastname: Von Aulock
authors.forename: Christian
authors.initials: C
authors.lastname: Draing
authors.forename: Corinne
authors.initials: C
authors.lastname: Marois
authors.forename: Marylène
authors.initials: M
authors.lastname: Kobisch
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
mesh_terms: D000409:Alanine / Q000378:metabolism*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases; D002460:Cell Line; D051263:D-Alanine Transaminase / Q000235:genetics; D042783:Endothelial Cells / Q000382:microbiology; D005260:Female; D017353:Gene Deletion; D008070:Lipopolysaccharides / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D050296:Microbial Viability; D009504:Neutrophils / Q000276:immunology; D013290:Streptococcal Infections / Q000382:microbiology; D017011:Streptococcus suis / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D016019:Survival Analysis; D013552:Swine; D013682:Teichoic Acids / Q000378:metabolism*; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid; D051263:D-Alanine Transaminase; D019729:Carbon-Oxygen Ligases; C502532:DltA protein, Bacillus subtilis; D000409:Alanine