title: Molecular analysis and experimental virulence of French and North American Escherichia coli neonatal meningitis isolates: identification of a new virulent clone.
abstract: Phylogenetic relationships, virulence factors, alone and in specific combinations, and virulence in a rat meningitis model were examined among 132 isolates of Escherichia coli neonatal meningitis from France and North America. Isolates belonging to phylogenetic groups A (n=11), D (n=20), and B2 (n=99) had similar high prevalence rates of the siderophores aerobactin and yersiniabactin and the K1 capsule (>/=70%) yet induced different level of experimental bacteremia. Ectochromosomal DNA-like domains involved in blood-brain barrier passage (PAI III(536) [sfa/foc and iroN; 34%]; GimA [ibeA and ptnC; 38%]; PAI II(J96) [hly, cnf1, and hra; 10%]) were restricted to B2 isolates. Among group B2 isolates, representatives of the O45:K1 clonal group (n=30), which lacked these domains, were as able as the archetypal O18:K1 strain C5 to cause meningitis. Molecular epidemiology combined with experimental virulence assays demonstrate that known virulence factors are insufficient to fully explain the pathophysiology of ECNM and to allow for rational search for new virulence factors.
authors.affiliation: Laboratoire d'Etudes de Génétique Bactérienne dans les Infections de l'Enfant (EA 3105), Université Denis Diderot-Paris 7, Service de Microbiologie, Hôpital Robert Debré, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bonacorsi
authors.forename: Olivier
authors.initials: O
authors.lastname: Clermont
authors.forename: Véronique
authors.initials: V
authors.lastname: Houdouin
authors.forename: Christophe
authors.initials: C
authors.lastname: Cordevant
authors.forename: Naima
authors.initials: N
authors.lastname: Brahimi
authors.forename: Armelle
authors.initials: A
authors.lastname: Marecat
authors.forename: Colin
authors.initials: C
authors.lastname: Tinsley
authors.forename: Xavier
authors.initials: X
authors.lastname: Nassif
authors.forename: Marc
authors.initials: M
authors.lastname: Lange
authors.forename: Edouard
authors.initials: E
authors.lastname: Bingen
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D020814:Meningitis, Escherichia coli / Q000453:epidemiology / Q000382:microbiology*; D008969:Molecular Sequence Data; D009656:North America / Q000453:epidemiology; D010802:Phylogeny; D051381:Rats; D017207:Rats, Sprague-Dawley; D021521:Ribotyping; D012703:Serotyping; D014774:Virulence