The Bacillus virulome in endophthalmitis.
The Bacillus virulome in endophthalmitis.
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DOI：
10.1099/mic.0.001057
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发表时间：
2021-05
期刊：
影响因子：
--
通讯作者：
Callegan MC
中科院分区：
文献类型：
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作者：
Coburn PS;Miller FC;Enty MA;Land C;LaGrow AL;Mursalin MH;Callegan MC
蜡状芽孢杆菌被认为是胃肠道综合征的病原体，但也可以引起一种破坏性的眼内感染，称为眼内炎。我们以前报道过PlcR/PAPR主控毒力因子调节系统调节眼内毒力，S层蛋白(SLpA)与蜡样芽孢杆菌眼内炎的严重程度有关。为了更好地了解其他蜡样芽孢杆菌毒力基因在眼内炎中的作用，通过RNA-Seq方法测量了疾病进展中点的一组因子的表达。几种细胞溶解毒素在体内的表达水平明显高于BHI。毒力调节基因Cody、gntR和nprR也在体内表达。然而，在这个时间点上，plcR/PAPR是检测不到的，尽管我们之前报道了一株PlcR缺陷的蜡样芽孢杆菌突变体在眼睛中减弱了。在感染过程中检测到运动相关基因Fla、FliF和MOTb，以及趋化相关基因CheA。我们以前已经证明，运动性和趋化性表型在蜡样芽孢杆菌眼内炎中很重要。锰超氧化物歧化酶的sodA2变异体是体内表达最高的基因。在感染过程中也检测到表层蛋白基因SLPA的表达，SLPA是Toll样受体2和−4的激活因子，尽管表达水平很低。在芽孢杆菌眼内炎的小鼠模型中表达的基因可能在蜡状芽孢杆菌眼内炎的独特毒力中发挥关键作用，并可能成为旨在减轻这种经常致盲的感染的严重程度的新疗法的候选者。
Bacillus cereus is recognized as a causative agent of gastrointestinal syndromes, but can also cause a devastating form of intraocular infection known as endophthalmitis. We have previously reported that the PlcR/PapR master virulence factor regulator system regulates intraocular virulence, and that the S-layer protein (SlpA) contributes to the severity of B. cereus endophthalmitis. To better understand the role of other B. cereus virulence genes in endophthalmitis, expression of a subset of factors was measured at the midpoint of disease progression in a murine model of endophthalmitis by RNA-Seq. Several cytolytic toxins were expressed at significantly higher levels in vivo than in BHI. The virulence regulators codY, gntR, and nprR were also expressed in vivo. However, at this timepoint, plcR/papR was not detectable, although we previously reported that a B. cereus mutant deficient in PlcR was attenuated in the eye. The motility-related genes fla, fliF, and motB, and the chemotaxis-related gene cheA were detected during infection. We have shown previously that motility and chemotaxis phenotypes are important in B. cereus endophthalmitis. The sodA2 variant of manganese superoxide dismutase was the most highly expressed gene in vivo. Expression of the surface layer protein gene, slpA, an activator of Toll-like receptors (TLR)-2 and −4, was also detected during infection, albeit at low levels. Genes expressed in a mouse model of Bacillus endophthalmitis might play crucial roles in the unique virulence of B. cereus endophthalmitis, and serve as candidates for novel therapies designed to attenuate the severity of this often blinding infection.