Molecular Characterization and Toxinotyping of a Clostridium perfringens Isolate from a Case of Necrotic Enteritis in Indian Kadaknath Fowl

摘要

Necrotic enteritis, caused by Clostridium perfringens , is an important bacterial disease of poultry. A suspected case of necrotic enteritis was presented for necropsy from an Indian Kadaknath Fowl flock showing diarrhea and progressive debility. Gross examination revealed necrotic to ulcerative lesions in intestine. The organism was isolated from the intestinal contents, tissue and liver under anerobic conditions. The cultural characteristics and Gram staining were suggestive of C. perfringens . The sequencing of 16s rRNA gene confirmed the isolate as C. perfringens and which was well differentiated from other clostridia associated with avian intestinal tract. This study demonstrates that 16s rRNA gene sequencing can provide rapid and confirmatory identification of C. perfringens. Further, Multiplex Polymerase Chain Reaction (mPCR) was performed for toxinotyping and isolate was found to be positive for α toxin ( cpa ) and β2 toxin ( cpb2 ), a feature of C. perfringens type A isolates. As some recent studies have highlighted the involvement of NetB toxin in pathogenesis, therefore, PCR was carried out to find the presence of this toxin, the isolate was found to be negative for netB gene. This study emphasizes the molecular characterization and toxinotyping as a rapid tool for detection of C. perfringens from suspected necrotic enteritis cases. Very few reports regarding molecular characterization are available from India, hence it adds to the available data on this important poultry pathogen. Further investigations are required to understand the exact role of NetB toxin in pathogenesis as various studies including the current one reports NetB negative strains involved in necrotic enteritis.