TY - BOOK AU - Asmaa Shaaban Tantawy Ali AU - Basma Shalaby Mahmoud , AU - Sahar Ahmed Zou-Elfakar , AU - Youssef Ibrahim Youssef , TI - Studies on clostridial infection in chickens / PY - 2017/// CY - Cairo : PB - Asmaa Shaaban Tantawy Ali , KW - C. perfringens KW - incidence KW - NE N1 - Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Animal Diseases; Issued also as CD N2 - A total of 247 intestinal samples from freshly dead broiler and layer chickens were collected from 150 farms in Giza, Sharkia, Qalubia, Elbehera, Daqahlia and Cairo governorates in different seasons. These samples showed different degrees of intestinal lesions from apparently normal to sever necrosis with ulcerations. Clostridium perfringens was isolated from 138 samples with incidence of 55.9%. The incidence of NE was higher in spring and summer than winter and autumn. According to polymerase chain reaction and intradermal injection of guinea pig all isolates were clostridium perfringens type A. In vitro antibiotic sensitivity tests made for 15 isolates and most of the examined isolates were highly sensitive to Amoxicillin, ampicillin, florfenicol, penicillin and metronidazole. Three isolates showed resistance to most of antibiotics were used. Effect of piperazine salt on antibiotic resistance of C. perfringens isolate was studied in this work. Sequence analysis for three resistant isolates showed no mutation. Experimental infection with multiple doses of C. perfringens type A given intra crop in one day SPF chickens resulted in subclinical NE diagnosed by decreased BWG and histobathological lesions in intestine and liver. Evaluation of the effect of antibiotic on piprazine treated group and probiotic against experimental infection with C. perfringens type A resulted in improvement of BWG and minimizing the appearance of PM and histopathological lesions ER -