Accession Number:

ADA273607

Title:

Pili in Microspheres Protect Rabbits From Diarrhoea Induced by E. Coli Strain RDEC-1

Descriptive Note:

Corporate Author:

WALTER REED ARMY INST OF RESEARCH WASHINGTON DC

Report Date:

1993-01-01

Pagination or Media Count:

7.0

Abstract:

We tested whether pilus proteins of rabbit diarrhoeagenic Escherichia coli RDEC-1, incorporated into biodegradable microspheres, could function as safe and effective oral immunogens in the rabbit diarrhoea model. The RDEC-1 adhesin, AFR1, incorporated into polyD,L-lactide-co-glycolide microspheres, was administered intraduodenally. Vaccinated and unvaccinated rabbits were challenged with RDEC-1 and killed 1 week later. Vaccination with AFR1 in microspheres did not cause diarrhoea or weight loss. After challenge, rabbits given AFR1 in microspheres, in contrast to unvaccinated animals, remained in good health. RDEC-1 attachment to caecal epithelium of vaccinated rabbits was reduced p0.02, whereas numbers of RDEC-1 in intestinal fluids were little affected. Also, in vaccinated animals, biliary anti-AFR1 IgA levels were increased, and AFR1-induced blast-cell transformation was vigorous in spleen cell cultures. We conclude that vaccination with AFR1 in microspheres was safe and protected rabbits against RDEC-1 disease, probably by interfering with adherence of the bacteria to the intestinal mucosa. The interference might have been due to the presence of specific antibodies secreted in bile

Subject Categories:

  • Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE