title: Plasmid-controlled colonization factor associated with virulence in Esherichia coli enterotoxigenic for humans.
abstract: An enterotoxin-producing strain of Escherichia coli isolated from a case of cholera-like diarrhea (E. coli strain H-10407) was found to possess a surface-associated colonization factor. Colonization was manifested as the ability of small inocula (10(5) bacteria) to attain large (10(9)) populations in the infant rabbit intestine with a concomitant diarrheal response. A laboratory-passed derivative of E. coli H-10407, designated H-10407-P, failed to exhibit an increase in population in the infant rabbit and also failed to induce diarrhea. Cell-free culture supernatant fluids of E. coli H-10407 and H-10407-P produced equivalent enterotoxic responses in infant and in adult rabbits. Specific anti-colonization factor antiserum was produced by adsorbing hyperimmune anti-H-10407 serum with both heat-killed and living cells E. coli H-10407-P. This specific adsorbed serum protected infant rabbits from challenge with living E. coli H-10407 although the serum did not possess bactericidal activity. The anti-colonization factor serum did not agglutinate a strain of E. coli K-12 possessing the K88 colonization factor peculiar to E. coli enterotoxigenic for swine. By electron microscopy it was demonstrated that E. coli H-10407, but not H10407-, possessed pilus-like surface structures which agglutinated with the specific adsorbed (anti-colonization factor) antiserum. E. coli H-10407 possessed three species of plasmid deoxyribonucleic acid, measuring 60 X 10(6), 42 X 10(6), and 3.7 X 10(6) daltons, respectively. E. coli H-10407-P possessed only the 42 X 10(6)- and the 3.7 X 10(6)-dalton plasmid species. Spontaneous loss of the specific H-10407 surface-associated antigen was accompanied by loss of the 60 X 10(6)-dalton species of plasmid deoxyribonucleic acid and loss of colonizing ability. Thus, it is concluded that the E. coli colonization factor described here is a virulence factor which may play an important and possibly essential role in naturally occurring E. coli enterotoxic diarrhea in man.
mesh_terms: D000327:Adsorption; D000371:Agglutination; D000818:Animals; D001431:Bacteriological Techniques; D004247:DNA / Q000096:biosynthesis; D004768:Enterotoxins / Q000633:toxicity; D004926:Escherichia coli / Q000276:immunology* / Q000648:ultrastructure; D005111:Extrachromosomal Inheritance; D006801:Humans; D007082:Ileum / Q000276:immunology; D007106:Immune Sera; D008854:Microscopy, Electron; D009500:Neutralization Tests; D010957:Plasmids; D011817:Rabbits; D014774:Virulence
chemical_list: D004768:Enterotoxins; D007106:Immune Sera; D004247:DNA