Morphological and immunocytochemical analysis of Escherichia coli-specific surface antigens in wildtype strains and in recombinant Vibrio cholerae.
Adhesion is the first step in the pathogenesis of enterotoxigenic Escherichia coli infections. The genes encoding the most prevalent adhesion factors CFA/I, CS3 and CS6 were cloned into Vibrio cholerae strain CVD 103-HgR and expression of fimbriae was investigated in wildtype and recombinant strains by transmission electron microscopy in conjunction with immunolabelling and negative staining. Negative staining was effective in revealing CFA/I and CS3, but not CS6. Although morphology of fimbriae differed between wildtype and recombinant strains, corresponding surface antigens were recognized by specific antibodies. The present study provides evidence that ETEC-specific fimbriae can adequately be expressed in an attenuated V. cholerae vaccine strain and that immunoelectron microscopy is a critical tool to validate the surface expression of antigens in view of their possible suitability for recombinant vaccines.
Lüdi
Stefan
S
Division of Veterinary Anatomy, Vetsuisse Faculty University of Berne, P.O. Box 8466, 3001 Bern, Switzerland.
Frey
Joachim
J
Favre
Didier
D
Viret
Jean-François
JF
Ziethlow
Verena
V
Boghenbor
Kathrin Kühni
KK
Stoffel
Michael H
MH
D000942:Antigens, Bacterial / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D004274:DNA, Recombinant / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure; D010861:Fimbriae, Bacterial / Q000378:metabolism / Q000648:ultrastructure; D005838:Genotype; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
D000942:Antigens, Bacterial; D004274:DNA, Recombinant