RESUMEN
Clostridium perfringens is more prevalent type of clostridia genus isolated from the intestinal tract of ostrich [Struthio camelus]. Necrotic enteritis [NE] is a potentially fatal gastrointestinal [GI] disease of poultry and other avian species, which produces marked destruction of intestinal lining in digestive tract caused by C. perfringens. Pathogenicity and lesions are correlated with the toxins produced, thus toxin typing of the bacterium has diagnostic and epidemiological significance. The aims of the present study were to determine the biotypes of C. perfringens among ostrich's farms either diseased and healthy ones and to screen the isolates for major toxin genes [cpa, cpb, etx, and iA, cpb2, andcpe]. Thirty isolates of C. perfringens were obtained from NE-positive and NE-negative ostrich flocks in Khorasan-e-Razavi porvince and analyzed by multiplex PCR assay. All isolates were positive for alpha toxin gene [cpa] and five of those were positive for beta toxin gene [cpb]. The presence of cpb2 gene was detected in a high percentage of isolates originating from both healthy [93.3%] and diseased flocks [80%]. None of the isolates carried enterotoxin gene [cpe]. The results suggest that types A and C of C. perfringens are the most prevalent types in ostrich in Iran. Due to detection of beta2 toxin gene in isolates from both healthy and diseased birds, it appears that the presence of cpb2 is not considered a risk by itself