Genes de virulence.pdf


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The E. coli genome. The diagram represents an E. coli cell harbouring the K12 chromosome.
Insertion sites for some well-characterised DNA elements and pathogenicity islands
(represented as bars) are shown. These are located at mapped insertion sites with the apex of
the ellipse representing zero minutes on the genome, as designated by Blattner et al. [23].
Hatched bars represent uropathogenic E. coli-associated sequences, whereas black bars
indicate those associated with EHEC or EPEC. The open bars show genetic material
associated with neuroinvasive E. coli and capsule (kps, cps) production. The smaller ellipses
at the bottom of the diagram represent examples of the many E. coli plasmids carrying
determinants not found in K12. These include EAF (which encodes bundle-forming pili from
EPEC), AAF (which encodes adherence fimbriae from enteroaggregative E. coli), Fim (which
encodes colonisation factors such as K88, K99 and human CFs), Ent (which encodes heat-labile
and heat-stable enterotoxins), pCG86 (which encodes antibiotic resistance and enterotoxin
production), ColV (which encodes colicin production and self-immunity to colicin), Hly
(which encodes a haemolysin), pVM01 (which encodes siderophore production) and Vir
(which encodes necrotizing factor 2 and F17b fimbriae). The pentagon-shaped structures show
phage attachment sites. Mins, minutes.