IN VIVO EXPERIMENTAL STUDIES ON CLOSTRIDIUM PERFRINGENS Tpel TOXIN
Mostafa Galal, Ola Basha, Hoda Abd-Ellatieff, Abdelrahman Abou Rawash and Madiha Salah Ibrahim*
The present study was conducted to evaluate the prevalence of C. Perfringens in boiler chickens in El Behiera and Matrouh governorates. Samples (n=362) were collected from intestine (n=162), feed (n=100) and litter (n=100). The prevalence of C. Perfringens was 49.1, 82.5, 60 and 50% in apparently healthy birds, diseased birds, feed and litter, respectively. Isolates were confirmed by Matrix-assisted laser desorption/ionization (MALDI). Antimicrobial susceptibility of C. perfringens showed sensitivity to Cefotaxime, Chloramphenicol, Bacitracin, Norfloxacin, Ciprofloxacin, Doxycycline, Telmicosin, Amoxicillin + Clavulanic acid and Clindamycin, while resistant to Gentamycin, Erythromycin, Amoxicillin and Neomycin. Eighteen C. perfringens isolates were examined by multiplex PCR using specific primers for Alpha, Beta, Epsilon and Iota genes. The alpha gene was detected in 17 of the examined isolates. By PCR, only five isolates were positive for the Tpel toxin gene. Further, the Net-B toxin gene was detected in one isolate. By neutralization test in mice and Dermonecrotic test in Albino guinea pigs, 5 C. perfringens isolates were toxigenic (type-A). Furthermore, experimental effect of trypsin on Tpel toxin in guinea pigs showed inhibition of the Tpel pathogenic effect. Bla and Erm-B genes specific to resistance of C. perfringens to beta lactam and macrolides, respectively, were detected by PCR in 100% and 60% of the tested isolates, respectively. These results showed matching between phenotypic and genotypic resistance in C. Perfringens. Further, environmental factors (feed and litter) represent an important source of toxigenic C. perfringens infection and apparently healthy birds may act as a major source of infection
Keywords: Broiler chickens, C. Perfringens, Tpel gene, PCR, Trypsin, Beta lactams, Macrolides.
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