Veterinary Archives, Vol. 79 No. 2, 2009.
Original scientific paper
Day-old infant rabbit model for enterohaemorrhagic Escherichia coli induced diarrhoea
Mashood Abiola Raji
; Department of Veterinary Microbiology and Parasitology, Sokoine University of Agriculture, Morogoro, Tanzania
Uswege Minga
; Department of Veterinary Microbiology and Parasitology, Sokoine University of Agriculture, Morogoro, Tanzania
Robert Machangu
; Department of Veterinary Microbiology and Parasitology, Sokoine University of Agriculture, Morogoro, Tanzania
Abstract
Day-old infant rabbits inoculated with enterohaemorrhagic Escherichia coli (EHEC) O157:H7 strain developed severe diarrhoea and ruffl ed coats, usually culminating in death. All rabbits (n=8) inoculated intragastrically with either UMDL 29 or MC 110 developed severe diarrhoea two days post inoculation. None of the control rabbits inoculated with PBS developed diarrhoea. The UMDL 29 and MC 110 infected rabbits also developed ruffl ed coats by day two post inoculation. Mortality started to occur on day four post infection. The diarrhoea which started 24 hr post inoculation was associated with loss of mass and infl ammation of the intestines. At necropsy, the ceca and colons of rabbits inoculated with either UMDL 29 or MC 110 were distended or fi lled with loose stool and fl uids. In contrast, the ceca and colons of rabbits inoculated with PBS were not distended and contained hard, formed pellets. The intestinal contents of the infected rabbits that died and of those that were euthanatized were fi lled with watery content. A microscopic examination of colons showed mild infl ammatory cell infi ltration, thinning of the intestinal wall, or necrotic foci. The lungs of infected rabbits were congested. The limitations of current animal models led us to reexamine the day-old infant rabbit model for the study of EHEC pathogenicity. This study indicates that infant rabbits are a useful model for investigation of the intestinal stage of EHEC pathogenesis and suggest that shiga toxin and other virulence factors of E. coli O157 may play a critical role in causing diarrhea and infl ammation in patients infected with EHEC.
Keywords
pathogenicity; day-old rabbits; Escherichia coli O157; humans; animals
Hrčak ID:
37323
URI
Publication date:
20.4.2009.
Visits: 1.241 *