Gao Qun, Lu Shuwei, Wang Mingshu, Jia Renyong, Chen Shun, Zhu Dekang, Liu Mafeng, Zhao Xinxin, Yang Qiao, Wu Ying, Zhang Shaqiu, Huang Juan, Mao Sai, Ou Xumin, Sun Di, Tian Bin, Cheng Anchun
Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Front Microbiol. 2021 Sep 20;12:708225. doi: 10.3389/fmicb.2021.708225. eCollection 2021.
causes serious contagious disease in ducks, geese, and other fowl. However, as a harmful pathogen causing significant economic losses in the poultry industry, is still poorly understood for its pathogenesis mechanisms. In a previous study, we developed an indirect ELISA method for detecting infection using B739_0832 protein, a putative outer membrane protein H (OmpH) that is conserved among different serotypes of . Although OmpH in some pathogenic bacteria, such as , has been reported as a virulence factor, it is still not clear whether B739_0832 protein contributes to the virulence of . In this study, we confirmed that B739_0832 protein in localizes to the outer membrane. We constructed a deletion mutant strain (Δ) and assayed various effects from the deletion of B739_0832. Δ0832 strain had a similar growth rate to wild-type CH-1. However, the survival rate of ducklings in 10 days after infection from Δ0832 strain was 50%, whereas no ducklings survived from wild-type infection. Furthermore, the median lethal dose (LD) of the Δ0832 strain was approximately 150 times higher than that of the wild-type strain. Pathology examinations on infected ducklings found that, at 36 h after infection, bacterial loads in blood, liver, and brain tissues from Δ0832-infected ducklings were considerably lower than those from wild-type infected ducklings. These results demonstrate that the B739_0832 protein contributes to the virulence of CH-1.
在鸭、鹅和其他禽类中引发严重的传染病。然而，作为在家禽业造成重大经济损失的有害病原体，其致病机制仍知之甚少。在先前的一项研究中，我们开发了一种间接ELISA方法，使用B739_0832蛋白检测感染，B739_0832蛋白是一种假定的外膜蛋白H（OmpH），在不同血清型的中保守。尽管在一些致病细菌如中，OmpH已被报道为一种毒力因子，但B739_0832蛋白是否有助于的毒力仍不清楚。在本研究中，我们证实中的B739_0832蛋白定位于外膜。我们构建了一个缺失突变株（Δ），并检测了缺失B739_0832的各种影响。Δ0832株的生长速率与野生型CH-1相似。然而，感染Δ0832株10天后雏鸭的存活率为50%，而野生型感染的雏鸭无一存活。此外，Δ0832株的半数致死剂量（LD）比野生型菌株高约150倍。对感染雏鸭的病理学检查发现，感染后36小时，Δ0832感染雏鸭血液、肝脏和脑组织中的细菌载量明显低于野生型感染雏鸭。这些结果表明，B739_0832蛋白有助于CH-1的毒力。
