Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511 Egypt.
Department of Pathology and Parasitology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511 Egypt.
Avian Dis. 2020 Dec 1;64(4):536-541. doi: 10.1637/aviandiseases-D20-00051.
The prevalence of Gallibacterium anatis in poultry production has increased over the last two decades. However, only a few studies have explored the pathogenicity of this bacterium in commercial layer chickens. This trial studied the aspects of the pathogenicity of a Gallibacterium anatis biovar haemolytica local Egyptian isolate (previously registered as strain B14 with GenBank accession no. KJ026147). We used 500 base pairs of a 16S ribosomal RNA gene and the 16S-23S ribosomal RNA intergenic spacer, partial sequence in an experimental infection trial in commercial White Shaver layer chickens aged 19 wk. The hens were divided into three groups of 40 birds each. The hens in Groups 1 and 2 were experimentally infected through the intranasal (IN) and intravenous (IV) routes, respectively, with a dose of 0.2 ml/bird containing 1.2 × 109 colony-forming units/ml. In contrast, Group 3 was kept as a noninfected control group. Both IN and IV infections resulted in a delayed egg laying for 1 wk and a significant (P ≤ 0.05) drop in egg production by 7.81% and 10.28% compared with the control group over 7 wk. Severe lesions in the form of hemorrhagic pneumonia, catarrhal tracheitis, ovarian follicle and oviductal regression, and septicemia were evident on necropsy, demonstrating the pathogenicity of G. anatis as a primary pathogen.
在过去的二十年中，禽源鸡败血支原体在禽类养殖中的流行率有所增加。然而，仅有少数研究探索了该细菌在商业蛋鸡中的致病性。本试验研究了一株禽源鸡败血支原体生物型溶血株埃及当地分离株（先前已在 GenBank 登记，登录号为 KJ026147，菌株编号为 B14）的致病性。我们使用了 500 个碱基对的 16S 核糖体 RNA 基因和 16S-23S 核糖体 RNA 基因间隔区，对 19 周龄商业白莎福蛋鸡进行了实验感染试验。将母鸡分为每组 40 只的三组。第 1 组和第 2 组母鸡分别通过鼻腔（IN）和静脉（IV）途径以 0.2ml/只的剂量感染，剂量中含有 1.2×109个菌落形成单位/ml。相比之下，第 3 组作为未感染对照组。IN 和 IV 感染均导致产蛋延迟 1 周，与对照组相比，产蛋量在 7 周内分别显著下降了 7.81%和 10.28%。剖检可见严重的病变，包括出血性肺炎、卡他性气管支气管炎、卵巢滤泡和输卵管退化以及败血病，表明鸡败血支原体是原发性病原体，具有致病性。
