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Clostridium perfringens -induced necrotic enteritis ( NE ) is an economically important disease of broiler chickens. The present study evaluated the effect of C. perfringens on the intestinal histomorphometry, enteric microbial colonization, and host immune responses using 3 experimental NE reproduction methods. The experimental groups consisted of 1) unchallenged Control diet (corn-soybean meal), 2) Control diet + Eimera inoculation at d 11 followed by C. perfringens challenge at d 15 ( ECp ), 3) Wheat-based diet + C. perfringens challenge ( WCp ), and 4) Wheat-based diet + Eimeria inoculation followed by C. perfringens challenge ( WECp ). The results showed that chickens receiving ECp and WECp had reduced ( P < 0.05) bird performance coupled with enteric gross lesions and epithelial damage at d 17 and 24 of age compared to unchallenged control birds. These ECp and WECp administered birds also had increased ( P < 0.05) ileal colonization by clostridia and E. coli at d 17 and 24, while the resident Lactobacillus counts were reduced ( P < 0.05) at d 24 of age. Furthermore, at d 24, jejunal transcription of IL-6, IL-10, annexin-A1 and IL-2 genes was upregulated ( P < 0.05) in the ECp group, whereas the transcription of TNF receptor associated factor (TRAF)-3 gene was increased ( P < 0.05) in WECp treated birds when compared to unchallenged control group. Additionally, stimulation of chicken splenocytes and cecal tonsilocytes with virulent C. perfringens bacilli or their secretory proteins resulted in a higher ( P < 0.05) frequency of T cells and their upregulation of MHC-II molecule, as determined by flow cytometry. These findings suggest that C. perfringens , while inducing epithelial damage and changes in microbiota, can also trigger host immune responses. Furthermore, NE reproduction methods using coccidia with or without the wheat-based dietary predisposition seem to facilitate an optimal NE reproduction in broiler chickens and thus, may provide better avenues for future C. perfringens research.

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Necrotic enteritis due to Clostridium perfringens strains harboring the netB gene is a well-known disorder in poultry. The aim of this study was to investigate the association of a novel bacteriocin, perfrin, with netB among isolates from healthy and diseased ostriches and broiler chickens. Forty-six C. perfringens isolates from broiler chickens and ostriches collected from 2010 to 2014 were included in this study and subjected to PCR to detect netB and perfrin genes. Six (60%) and 9 (25%) isolates were positive for both netB and perfrin genes in broilers and ostriches, respectively. Statistical analysis found a significant difference between healthy and diseased flocks for perfrin both in broilers and ostriches. For netB, the significant difference was only found between healthy and diseased ostrich flocks. This is the first report of the presence of perfrin in netB-positive C. perfringens strains in ostriches.