Corynebacterium pseudotuberculosis infection in adult ewes by inoculation in the external ear.
Caseous lymphadenitis, caused by Corynebacterium pseudotuberculosis, was studied in ewes to devise a reliable method of induced infection that would help to understand mechanisms by which abscesses develop in lymph nodes or internal organs, especially the lungs. Fifteen adult ewes, from a flock where the occurrence of caseous lymphadenitis was unknown, were inoculated SC in the auricle with various doses of a virulent strain of C pseudotuberculosis. Ewes inoculated with at least 10(8) viable corynebacteria develop a strong local reaction that was apparent 4 hours after challenge exposure and lasted 7 to 14 days. Of these ewes, all developed at least 1 abscess and 3 developed multiple abscesses in lymph nodes draining the inoculated auricle and in the lungs. All infected ewes developed a strong antibody response against C pseudotuberculosis exotoxin, which persisted for 3 months. Of 9 ewes infected with 1.2 X 10(8) corynebacteria, 3 developed lesions because of field strains of C pseudotuberculosis and had an increased capacity to limit the dissemination of challenge-inoculum bacteria by developing only one abscess in the draining lymph node (parotid or prescapular lymph node). Seemingly, inoculation in the external ear was a suitable method for obtaining a reproducible infection and indicated that a primary infection might protect against reinfection by limiting dissemination of C pseudotuberculosis.
Pépin
M
M
Institut National de la Recherche Agronomique, Laboratorie de Pathologie de la Reproduction, Nouzilly, France.
Pardon
P
P
Marly
J
J
Lantier
F
F
D000038:Abscess / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D003352:Corynebacterium / Q000276:immunology; D003354:Corynebacterium Infections / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D004431:Ear, External; D005260:Female; D008169:Lung Abscess / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D008199:Lymphadenitis / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000209:etiology* / Q000473:pathology
D000907:Antibodies, Bacterial