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). Bacteria were killed by formalin and administered per os for 10 consecutive days after weaning at a daily dose of 4 X 10(9) organisms. Six days after the last administration, all the animals were challenged with 1 X 10(4) virulent E. coli O103/10 and the experimental infection was monitored for 26 days. All rabbits in Group A were protected from symptoms of disease and remained alive, whereas two rabbits in Group B developed clinical signs and one died. Protection did not correlate with local or general responses to lipopolysaccharide (LPS) O103, as judged by measurement of anti-LPS O103 IgA in faeces or serum, or by serum agglutinating antibodies. Numbers of E. coli and E. coli O103 were significantly lower in vaccinated animals of Group A as compared with animals of the control group. The differences between both vaccine regimens may be partially explained by a different expression of the adhesins of strain O103/10, depending on the medium used to prepare the vaccine.
Camguilhem
R
R
Laboratoire de Pathologie du Bétail et des Animaux de Basse-Cour, Toulouse, France.
Milon
A
A
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001422:Bacterial Adhesion; D001428:Bacterial Vaccines / Q000276:immunology; D002432:Cecum / Q000382:microbiology; D004760:Enterocolitis / Q000517:prevention & control / Q000662:veterinary*; D004926:Escherichia coli / Q000254:growth & development / Q000276:immunology* / Q000648:ultrastructure; D004927:Escherichia coli Infections / Q000517:prevention & control / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D008297:Male; D008854:Microscopy, Electron; D011817:Rabbits; D011897:Random Allocation; D014611:Vaccination / Q000662:veterinary; D014886:Weaning; D015430:Weight Gain
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines