Oral vaccination of weaned rabbits against enteropathogenic Escherichia coli-like E. coli O103 infection: use of heterologous strains harboring lipopolysaccharide or adhesin of pathogenic strains.

To test the importance of lipopolysaccharide (LPS) and adhesin as major antigens in vaccination against rabbit enteropathogenic Escherichia coli (EPEC)-like E. coli O103 infection, we used two nonpathogenic wild-type strains to immunize rabbits at weaning. One of these strains (C127) harbors the O103 LPS but does not express the 32,000-molecular-weight adhesin that characterizes the highly pathogenic O103 strains.

Adhesion of Escherichia coli strains isolated from diarrheic weaned rabbits to intestinal villi and HeLa cells.

Thirty-eight strains, representative of 575 Escherichia coli isolates from weaned diarrheic rabbits, were tested for their ability to adhere in vitro to rabbit intestinal villi and to HeLa 229 cells. The O103 rhamnose-negative, highly pathogenic strains, which are epidemiologically predominant in France, attached to intestinal villi prepared from 8-day-old as well as 6-week-old rabbits and gave a diffuse adhesion pattern with HeLa cells. These adhesion properties were associated with the presence of a protein with a molecular weight of 32,000 in surface extracts of the strains.

Protection of weaned rabbits against experimental Escherichia coli O103 intestinal infection by oral formalin-killed vaccine.

In an attempt to vaccinate young weaned rabbits against life-threatening enterocolitis caused by Escherichia coli of the O103 serogroup, 32 New Zealand male rabbits were divided into three groups. One group remained unvaccinated as a control (Group C), and each of the other groups received one of two types of vaccine prepared with E. coli strain O103/10 cultured either in trypticase-soy broth (Group A) or in Minca agar (Group B).

Biotypes and O serogroups of Escherichia coli involved in intestinal infections of weaned rabbits: clues to diagnosis of pathogenic strains.

A total of 575 Escherichia coli strains isolated from weaned rabbits experiencing diarrhea in 119 French commercial farms were tested for O serogroups. The results showed a strong predominance of serogroup O103 strains. A sample of 126 strains were further checked for simplified biotypes by using five carbohydrate fermentation reactions.

[Experimental study of diarrhea induced by a strain of Escherichia coli (serogroup O-103) in growing rabbits].

The experimental infection by mouth of weaned, 6 week old rabbits was performed with Escherichia coli strain O-103/10 without any adjuvant. The quantities of E. coli for the 3 experimental treatments were - none (control) - 10(4) or 10(7) per animal.