Analysis of potential virulence genes and competence to transformation in Haemophilus influenzae biotype aegyptius associated with Brazilian Purpuric Fever.
Analysis of potential virulence genes and competence to transformation in Haemophilus influenzae biotype aegyptius associated with Brazilian Purpuric Fever.
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DOI：
10.1590/1678-4685-gmb-2020-0029
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发表时间：
2020
影响因子：
2.1
通讯作者：
Lancellotti M
中科院分区：
文献类型：
--
作者：
Pereira RFC;Theizen TH;Machado D;Guarnieri JPO;Gomide GP;Hollanda LM;Lancellotti M
巴西紫癜热（BPF）是一种由埃及流感嗜血杆菌（Hae）引起的出血性儿科疾病，Hae是一种以前与自限性化脓性结膜炎相关的细菌。BPF被认为已经根除。然而，与BPF相关的Hae菌株的内在毒力机制仍然是一个谜，研究不足。在这里，我们的目的是分析的作用，相关的粘附和殖民las，tabA 1，hadA基因通过RT-qPCR表达谱和敲除突变体的自转运基因。在人细胞和幼年大鼠模型中感染后通过实时PCR进行的相对定量表明，las最初可能由于免疫逃避而下调，tabA 1和hadA通常过表达，这表明TabA 1和HadA 1粘附素在体外和体内Hae中的积极作用。尽管使用了多种技术方法，但转化尝试均未成功，并且计算机分析显示Hae缺乏与嗜血杆菌中的感受态相关的基因，这可能是阐明遗传操纵Hae菌株的困难的一部分。
Brazilian Purpuric Fever (BPF) is a hemorrhagic pediatric illness caused by Haemophilus influenzae biogroup aegyptius (Hae), a bacterium that was formerly associated with self-limited purulent conjunctivitis. BPF is assumed to be eradicated. However, the virulence mechanisms inherent to Hae strains associated with BPF is still a mystery and deficient in studies. Here, we aim to analyze the role of the autotransporter genes related to adherence and colonization las, tabA1, and hadA genes through RT-qPCR expression profiling and knockout mutants. Relative quantification by real-time PCR after infection in human cells and infant rat model suggests that las was initially downregulated probably duo to immune evasion, tabA1, and hadA were overexpressed in general, suggesting an active role of TabA1 and HadA1 adhesins in Hae in vitro and in vivo. Transformation attempts were unsuccessful despite the use of multiple technical approaches and in silico analysis revealed that Hae lacks genes related to competence in Haemophilus, which could be part of the elucidation of the difficulty of genetically manipulating Hae strains.