isolation, identification, and antimicrobial susceptibility of clostridium perfringens isolates from acute necrotic enteritis of broiler chickens

the aim of this study was to isolate, identify and determine the antimicrobial susceptibility of clostridium perfringens (cp) isolates from acute necrotic enteritis of broiler chickens. all broiler carcasses diagnosed as necrotic enteritis (ne) were sampled, subjected to microbial tests and 40 isolates were identified according to standard procedures. the antimicrobial susceptibility of cp isolates to 20 antibacterial agents was then determined. the results show widespread resistance among cp isolates. the most frequent resistance was observed to neomycin sulfate (87.5%), and then to lincomycin and tetracycline (both 80%). no isolate was resistant to chloramphenicol and the least frequency of resistance was observed to vancomycin (10%), sulfamethoxazole+trimethoprim (17.5%), and penicillin (20%). all isolates were multiple drug resistant types. there were 39 resistant patterns among the cp isolates, 95% of which were distributed in 38 resistant patterns. these multiple and variable resistance patterns observed among the cp isolates, even among different isolates from one farm, demonstrate a challenge for veterinarians in the field to choose the correct compound to combat the occurrence of ne.