RESUMO
Broiler chickens were inoculated with different amounts of a Clostridium botulinum type C toxoid at 1 or 14 or both 1 and 14 days of age. Immunity was assessed following challenge with type C botulism toxin at 3, 6, and 8 weeks of age. Protection induced by toxoid injection was affected more by time and number of inoculations than by the amount of toxoid administered. Single toxoid injections at one day of age furnished poor protection, whereas groups injected at 14 days of age were well protected at 6 and 8 weeks of age but not at 3 weeks of age. Variable results were observed in groups inoculated at both 1 and 14 days of age: immunity was evident in some groups following 3-, 6-, and 8-week toxin challenges.
Assuntos
Vacinas Bacterianas , Botulismo/veterinária , Galinhas/imunologia , Clostridium botulinum/imunologia , Doenças das Aves Domésticas/prevenção & controle , Toxoides , Vacinação/veterinária , Animais , Animais Recém-Nascidos/imunologia , Vacinas Bacterianas/administração & dosagem , Toxinas Botulínicas/farmacologia , Botulismo/prevenção & controle , Feminino , Camundongos , Toxoides/administração & dosagemRESUMO
Twenty-seven cases of type C botulism were studied in integrated broiler operations on the Delmarva Peninsula. Single and repeated outbreaks in broiler flocks were observed. No botulinum toxin was found in litter and feed samples despite repeated testing. Clostridium botulinum type C was cultured from litter, feed, and tissues of morbid and clinically normal chickens sampled from farms in which flocks experienced botulism. Clostridium botulinum type C could not be cultured from tissues of clinically normal chickens taken from a farm without a flock history of botulism or from caged broilers reared in semi-isolation.
Assuntos
Botulismo/veterinária , Galinhas , Doenças das Aves Domésticas/epidemiologia , Ração Animal , Animais , Botulismo/epidemiologia , Botulismo/microbiologia , Galinhas/microbiologia , Clostridium botulinum/classificação , Clostridium botulinum/isolamento & purificação , Delaware , Microbiologia de Alimentos , Esterco , Doenças das Aves Domésticas/microbiologiaRESUMO
Five isolates, from broiler-type chickens, capable of causing acute respiratory disease were identified as infectious bronchitis virus (IBV). The agar-gel precipitin (AGP) test was effective in identifying the isolates as IBV. Virus-neutralization (VN) and cross-challenge tests indicated two of the isolates to be Massachusetts types and one to be a JMK type. The remaining isolates were different from strains normally encountered in chickens reared on the Delmarva Peninsula. One isolate, although serologically similar to the Connecticut strain, was able to infect Connecticut-virus-immune chickens. Another isolate was similar to Arkansas 99, a strain not previously reported in Delmarva.