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 surfaceassociated colonization factor. Colonization was manifested as the ability of small inocula (105 bacteria) to attain large (10w) 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 of 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 H-10407-P, 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 10X, 42 x 106, and 3.7 x 10' daltons, respectively. E. coli H-10407-P possessed only the 42 x 106and the 3.7 x 106-dalton plasmid species. Spontaneous loss of the specific H-10407 surface-associated antigen was accompanied by loss of the 60 x 106-dalton species of

Two highly related regulatory proteins, Shigella flexneri VirF and enterotoxigenic Escherichia coli Rns, have common and distinct regulatory properties

“…Bacterial cultures were grown routinely in Luria (L) broth or on L agar plates (L broth containing 1.5% (w/v) agar) [10]. For the experiments on CS1 ¢mbrial gene expression, cultures were grown in CFA medium [11]. Where appropriate, antibiotic selection was with ampicillin (50 Wg ml 3I ), chloramphenicol (15 Wg ml 3I ), kanamycin (20 Wg ml 3I ), spectinomycin (50 Wg ml 3I ) or tetracycline (20 Wg ml 3I ).…”

Expression of antigenically distinct fimbriae with hemagglutination and HeLa cell adherence properties by an enteroaggregative Escherichia coli strain belonging to the enteropathogenic serogroup

“…Reference EPEC and EAggEC strains used were E2348/69 [11] and 17-2 [8] respectively. Reference enterotoxigenic E. coli (ETEC) strains used were H10407 [16] and PB176 [17]. A plasmid-less derivative (H10407 P) of ETEC strain H10407 expressing only type-1 fimbriae [16] was also included in this study.…”

“…Reference enterotoxigenic E. coli (ETEC) strains used were H10407 [16] and PB176 [17]. A plasmid-less derivative (H10407 P) of ETEC strain H10407 expressing only type-1 fimbriae [16] was also included in this study. A non-pathogenic E. coil K12 auxotroph C600 (F-, thr-, leu-, thi-, lac-) was used in this study as the recipient in conjugation experiments.…”

An apoptotic response by J774 macrophage cells is common upon infection with diarrheagenic Escherichia coli

“…We selected one well-studied strain as a representative for each category of diarrheagenic E. coli (see Table 1 for details): EAEC 042 [11], EHEC EDL933 [12], EIEC 4608-58 [13], EPEC E2348/69 [14], ETEC H10407 [15], DAEC 2787 [2] and ESIEC F171 [3,4]. E. coli K-12 strain HB101 [16] was used as negative control.…”