Focal duodenal necrosis (FDN) is an intestinal disease of egg-layer chickens characterized by multifocal necrosis of the duodenal loop and proximal jejunum. Affected flocks usually have decreased egg weights and drops in egg production. Previous studies have associated this condition with Clostridium perfringens infection. We tried to reproduce FDN by experimental infection of egg-laying chickens using different netB-positive and netB-negative C. perfringens strains, and duodenal homogenate obtained from FDN lesions. Chickens challenged with C. perfringens and/or duodenal homogenate developed duodenitis after challenge. Gross lesions included mucosal erosions, hyperemia, mucosal hemorrhages, and watery intestinal content. Microscopic lesions included mild enterocyte degeneration and necrosis, and mild-to-moderate hemorrhage and lymphoplasmacytic and heterophilic infiltration of the lamina propria. Two netB-positive C. perfringens strains closely related to necrotic enteritis pathogenic strains, by genomic composition, were re-isolated from lesions. Necrosis of intestinal crypts was observed in chickens challenged with duodenal homogenate with or without C. perfringens coinfection. Characteristic microscopic FDN lesions with significant necrosis and loss of villus enterocytes were not reproduced.

中文翻译：

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鸡的局灶性十二指肠坏死：尝试通过实验重现该疾病和诊断注意事项。


局灶性十二指肠坏死（FDN）是蛋鸡的一种肠道疾病，其特征是十二指肠环和近端空肠的多灶性坏死。受影响的鸡群通常蛋重下降，产蛋量下降。先前的研究已将这种情况与产气荚膜梭菌感染相关。我们尝试通过使用不同的netB阳性和netB阴性产气荚膜梭菌菌株以及从FDN病变获得的十二指肠匀浆对产蛋鸡进行实验感染来复制FDN。用产气荚膜梭菌和/或十二指肠匀浆攻击的鸡在攻击后出现十二指肠炎。肉眼病变包括粘膜糜烂、充血、粘膜出血和水样肠内容物。显微镜下病变包括轻度肠上皮细胞变性和坏死，以及轻至中度出血以及固有层淋巴浆细胞和异嗜性浸润。从病灶中重新分离出两种 netB 阳性产气荚膜梭菌菌株，其基因组组成与坏死性肠炎致病菌株密切相关。在用十二指肠匀浆攻击、有或没有产气荚膜梭菌共感染的鸡中观察到肠隐窝坏死。没有再现具有显着坏死和绒毛肠上皮细胞损失的特征性显微 FDN 损伤。