Anhui Province Key Laboratory of Veterinary and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, People's Republic of China.
Avian Pathol. 2020 Jun;49(3):211-220. doi: 10.1080/03079457.2019.1701182. Epub 2020 Mar 4.
As a transcriptional regulator of the classical binary regulatory system, PhoP plays an important role in the life activities of avian pathogenic (APEC). In previous experiments, we found that the absence of affects APEC biofilm formation and pathogenicity. To further explore the molecular mechanism of regulation of these phenomena, the differentially expressed gene was screened based on -derived transcriptional data, and the specific sequence identity of the PhoP binding sequence was predicted by bioinformatics and verified by electrophoretic mobility shift assay (EMSA). The results showed that PhoP can directly bind to the promoter. On this basis, deletion and complementary strains were constructed. Biofilm formation was quantified by crystal violet staining and rdar morphology change was observed in these strains. Loss of reduced biofilm formation. We also examined pathological changes in organ paraffin sections by challenging chicks with the strains. After loss of , the clinical signs of pericarditis and liver and spleen enlargement in chicks were alleviated, and pathogenicity to the host cells was decreased. Additionally, quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that deletion downregulated /// transcript levels, which are part of the type II secretion system secreting virulence effector element. These results indicate that contributes to the -mediated effect on APEC biofilm formation and pathogenicity.
作为经典二元调控系统的转录调控因子，PhoP 在禽致病性大肠杆菌（APEC）的生命活动中发挥着重要作用。在之前的实验中，我们发现 缺失会影响 APEC 生物膜形成和致病性。为了进一步探讨 调节这些现象的分子机制，我们基于 衍生的转录数据筛选了差异表达基因 ，并通过生物信息学预测和电泳迁移率变动分析（EMSA）验证了 PhoP 结合序列的特定序列同一性。结果表明，PhoP 可以直接结合到 启动子上。在此基础上，构建了 缺失和互补菌株。通过结晶紫染色定量生物膜形成，并观察这些菌株中 rdar 形态变化。 缺失会减少生物膜形成。我们还通过用菌株攻雏鸡来检查器官石蜡切片中的病理变化。 缺失后，雏鸡的心包炎和肝脾肿大的临床症状得到缓解，对宿主细胞的致病性降低。此外，定量实时聚合酶链反应（qRT-PCR）分析显示， 缺失会下调 /// 转录本水平，这是 II 型分泌系统分泌毒力效应因子的一部分。这些结果表明， 有助于 PhoP 介导的 APEC 生物膜形成和致病性的影响。
