The avian pathogenic Escherichia coli O2 strain E058 carrying the defined aerobactin-defective iucD or iucDiutA mutation is less virulent in the chicken
The avian pathogenic Escherichia coli O2 strain E058 carrying the defined aerobactin-defective iucD or iucDiutA mutation is less virulent in the chicken
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携带需氧菌素缺陷型 iucD 或 iucDiutA 突变的禽致病性大肠杆菌 O2 菌株 E058 对鸡的毒力较低
DOI：
10.1016/j.meegid.2014.12.038
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发表时间：
2015-03-01
影响因子：
3.2
通讯作者：
Liu, Xiufan
中科院分区：
文献类型：
--
作者：
Gao, Qingqing;Jia, Xingxing;Liu, Xiufan
禽致病性大肠杆菌（APEC）的致病机制主要是由需氧菌素的表达引起的。iucA、iucB、iucC和iucD参与需氧肌动蛋白的合成，iutA负责铁需氧肌动蛋白的特异性外膜受体蛋白的表达。构建了APEC O2菌株E058中iucD和iucDiutA的敲除突变体，分别命名为E058 Delta iucD和E058 Delta iucD Delta iutA。为了评估这些突变体的致病性，我们使用多种方法来评估突变对APEC E058毒力的影响。与野生型菌株E058相比，气杆菌素缺陷型突变体E058 Delta iucD和E058 Delta iucD Delta iutA表现出显著降低的致病性，这通过在选定器官中的低定殖程度或在体内被E058竞争超过来证明。用APEC E058攻击的鸡表现出典型的禽大肠杆菌病的体征和病变，而用突变体E058 Delta iucD或E058 Delta iucD Delta iutA接种的鸡表现出中度气囊炎、轻度心包炎和肝周炎。然而，突变体和野生型菌株在对无特定病原体鸡血清的抗性、HD-11细胞的摄入以及LB中的生长速率方面没有观察到显着差异。这些结果表明，lucD和lutA相关的毒力因子在APEC菌株E058的发病机制中起着重要作用。(C)2015 Elsevier B. V.版权所有。
The expression of aerobactin accounts for much of the pathogenesis of avian pathogenic Escherichia coil (APEC). iucA, iucB, iucC and iucD are involved in aerobactin synthesis and iutA is responsible for the expression of a specific outer membrane receptor protein for ferric aerobactin. Knockout mutants of iucD and iucDiutA in the APEC O2 strain E058 were constructed and named E058 Delta iucD and E058 Delta iucD Delta iutA, respectively. To evaluate the pathogenicity of these mutants, we used multiple approaches to assess the effects of mutations on the virulence of APEC E058. Aerobactin-defective mutants E058 Delta iucD and E058 Delta iucD Delta iutA showed significantly decreased pathogenicity compared with the wild-type strain E058, evidenced by the low extent of colonization in selected organs or being outcompeted by E058 in vivo. Chickens challenged with APEC E058 exhibited typical signs and lesions of avian colibacillosis, while those inoculated with the mutants E058 Delta iucD or E058 Delta iucD Delta iutA showed moderate airsacculitis, mild pericarditis and perihepatitis. However, no significant differences in resistance to specific-pathogen-free chicken serum, ingestion by HD-11 cells, and growth rates in LB were observed between the mutants and the wild-type strain. These results indicated that the lucD- and lutA-related virulence factors play a significant role in the pathogenesis of the APEC strain E058. (C) 2015 Elsevier B.V. All rights reserved.