Isolation and Characterization of Clostridium perfringens from Suspected Cases of Necrotic Enteritis (NE) in Broiler Chicken

Abstract

Considering necrotic enteritis (NE) as an economically important problem of broiler industry, a study was undertaken to establish the association of Clostridium perfringens with the disease. Screening of a total of 35 faecal samples/intestinal scrapping of broiler, either clinically affected or died due to suspected form of NE reveal 13 (37.14%) samples to be positive for C. perfringens, yielding an equal no. of isolates. All the isolates could exhibit cpa gene (α-toxin). Recovery of C. perfringens was found to be comparatively more from intestinal scrapings (10). Among the C. perfringens isolates, three were identified to be toxin type C, exhibiting cpb  (β-toxin) along with cpa gene, while the rest 10 were identified as toxin  type A. Profiling of the isolates for additional toxin gene (s) exhibited  presence of netB and tpeL in only one of the C. perfringens of toxin type  A. All the isolated C. perfringens, irrespective of toxin types could exhibit resistance towards different antimicrobial agents, of which eight were found to be resistant to more than one type of antimicrobial agents. Majority of the isolates were found to be resistant to ciprofloxacin and norfloxacin, while metronidazole, gatifloxacin, tigecycline, cefmetazole and clindamycin were found to be effective against the all the isolates. Release of toxins in the cell free supernatant was found to be comparatively higher, during the 6-8 hrs of incubation. Additional toxin genes made the C. perfringens toxin type A comparatively more pathogenic for mice.