الفهرس 
History of clostridial infection among chickensOnly 14 pages are availabe for public view
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Abstract
A total of ١٥٠ samples (intestine and liver) of apparently normal and diseased
broiler chickens affected with necrotic enteritis were studied by bacteriological and
biochemical methods. Clostridium perfringens was isolated from intestine of affected
chickens with an incidence of (٧٥٪) and from the liver of diseased broiler chickens
with an incidence of (٢٥٫٣٪). While, apparently normal chickens isolation from
intestine only with an incidence of (٣٠٪). Typing of toxigenic strains isolated from
broiler chickens by using dermonecrotic reaction in guinea pigs, The most prevalent
type was type ’’A’’ (٤٧٫٧٪) followed by type ’’C’’ (٣٥٫٤٪), type ’’B’’ (١٠٫٨٪) and type
’’D’’ (٦٫٢٪). A rapid and specific test for typing of ١٠ random selected strains of
Clostridium perfringens by using PCR . Three pairs of primers (reverse and forward
primers of alpha, beta and epsilon toxins were used to amplify the ٤٠٢bp, ٢٣٦bp and
٥٤١bp fragments of alpha, beta and epsilon toxin gene respectively. Broiler chicks
were vaccinated subcutaneously at ٧ and ٢١ days of age , followed ٧ days later
challenge with Clostridium perfringens type A&C. Non vaccinated birds challenged
with C. perfringens developed mean of score lesions of (١٫٨٨) while mean of score
lesions in vaccinated groups with toxoid of C. perfringens type A, toxoid of C.
perfringens type C and mixed toxoid vaccine prepared from type A and C were
٠٫١٧٣, ٠٫٢٣١ and ٠٫١٢٣ respectively. While immunization of broiler chickens with
killed vaccine (bacterin) revealed that mean of score lesions of non vaccinated
chickens was (٢٫٢٢٣) although, in vaccinated chickens with C. perfringens type A
bacterin, C. perfringens type C bacterin and mixed bacterin vaccine of type A&C
were ٠٫١٧, ٠٫٢١٦ and ٠٫١٤٦ respectively. Vaccination produced antibody response
which measured with ELISA and revealed that antibody titer in vaccinated birds with
(toxoid and bacterin) were higher than the antibody titers in non vaccinated birds.
These results suggest that vaccination of the broiler chicken with (toxoid and
bacterin) may protect the birds from challenge with C. perfringens and may serve as
effective vaccine.