Molecular analysis and experimental virulence of French and North American Escherichia coli neonatal meningitis isolates: identification of a new virulent clone.
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.
Bonacorsi
Stéphane
S
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.
Clermont
Olivier
O
Houdouin
Véronique
V
Cordevant
Christophe
C
Brahimi
Naima
N
Marecat
Armelle
A
Tinsley
Colin
C
Nassif
Xavier
X
Lange
Marc
M
Bingen
Edouard
E
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