A new putative fimbrial colonization factor, CS19, of human enterotoxigenic Escherichia coli.
A gene probe derived from the colonization factor antigen I (CFA/I) operon cross-hybridized at very low stringency to plasmid DNA from coli surface antigen 17 (CS17)-producing enterotoxigenic Escherichia coli (ETEC) and from the ETEC strain F595C, which was negative for previously described CFAs, CSs, and putative colonization factors (PCFs). A 16-kDa protein was identified in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of heat extracts prepared after growth of strain F595C at 37 degrees C on CFA agar containing bile salts. Transmission electron microscopy revealed bile salt- and temperature-dependent expression of fimbriae with a diameter of 7 nm. After transformation with a recombinant plasmid harboring the cfaR gene, which encodes a positive regulator of several CFAs, PCFs, and CSs, the 16-kDa protein was hyperexpressed. Polyclonal antibodies raised against this protein bound to the fimbriae and inhibited the adhesion of F595C bacteria to tissue-cultured Caco-2 cells. Nucleotide sequence determination of the gene encoding the 16-kDa fimbrial subunit revealed a high degree of amino acid sequence homology to the CFA/I, CS1, CS2, CS4, CS14, and CS17 polypeptides. The term CS19 is proposed for the new fimbria.
Grewal
H M
HM
Centre for International Health and Laboratory for Biotechnology, University of Bergen, Norway.
Valvatne
H
H
Bhan
M K
MK
van Dijk
L
L
Gaastra
W
W
Sommerfelt
H
H
D000372:Agglutination Tests; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D015139:Blotting, Southern; D018938:Caco-2 Cells; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000276:immunology* / Q000648:ultrastructure; D006801:Humans; D015151:Immunoblotting; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction
D001426:Bacterial Proteins; C022924:colonization factor antigens; D036781:Fimbriae Proteins