Necrotic enteritis is a highly prevalent global disease of poultry caused by C. perfringens, the disease
causes severe economic losses in poultry industry due to bird losses and costs of treatment and
preventive measures. In order to investigate the prevalence, the antimicrobial susceptibility as well as
molecular characterization of Alpha toxin of C. perfringens, a total of 85 samples (intestine = 46 and
liver =39) were collected aseptically from freshly dead chickens (with history of sever enteritis, 2-4
weeks old) from commercial broilers farms at Ismailia Governorate. Egypt. The collected samples were
subjected to bacteriological examination where the total percent of the isolated C. perfringens strains
was (57. 6%) (n=49). The antibiotic sensitivity test was carried out using disc diffusion method where
the isolated strains were sensitive to Ciprofloxacin (100%), Amoxicillin clavulinc acid (100%) and
penicillin (91,8%) and highly resistant to neomycin (100%), Streptomycin (100%) and Erythromcin
(89,8%). PCR protocol was applied for amplification and detection of Alpha toxin gene in the isolated
C. perfringens strains, where all the tested strains were carried Alpha toxin gene with specific amplicon
size at 402 bp. Briefly, combination of phenotypic and genotypic analysis of C. perfringens is a valuable
epidemiological tool for identification of isolates. PCR is a rapid and specific diagnostic tool used for
genetic detection of alpha toxin of C. perfringens. Antimicrobial susceptibility testing is necessary to
determine the drug of choice and monitoring resistance to different antibiotics