当前位置: X-MOL 学术Vet. Microbiol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Disruption of the Burkholderia pseudomallei two-component signal transduction system BbeR-BbeS leads to increased extracellular DNA secretion and altered biofilm formation.
Veterinary Microbiology ( IF 3.3 ) Pub Date : 2020-02-08 , DOI: 10.1016/j.vetmic.2020.108603
Priyangi A Alwis 1 , Puthayalai Treerat 1 , Lan Gong 2 , Deanna Deveson Lucas 1 , Elizabeth M Allwood 1 , Mark Prescott 2 , Rodney J Devenish 2 , Ben Adler 1 , John D Boyce 1
Affiliation  

Two-component signal transduction systems (TCSTS) are abundant among prokaryotes and regulate important functions, including drug resistance and virulence. The Gram-negative bacterium Burkholderia pseudomallei, which causes the severe infectious disease melioidosis, encodes 136 putative TCSTS components. In silico analyses of these TCSTS indicated that the predicted BbeR-BbeS system (BPSL1036-BPSL1037) displayed significant amino acid sequence similarity to the Shigella flexneri virulence-associated OmpR-EnvZ osmoregulator. To assess the function of the B. pseudomallei BbeR-BbeS system, we constructed by allelic exchange a ΔbbeRS double mutant strain lacking both genes, and single ΔbbeR and ΔbbeS mutants. All three mutant strains caused disease in the BALB/c acute melioidosis model at the same rate as the wild-type strain, displayed unchanged swarming motility on semi-solid medium, and were unaffected for viability on high-osmolarity media. However, when cultured at 37 °C for at least 14 days, ΔbbeS and ΔbbeR colonies developed a distinct, hypermucoid morphology absent in similarly-cultured wild-type colonies. At both 30 °C and 37 °C, these hypermucoid strains produced wild-type levels of type I capsule but released increased quantities of extracellular DNA (eDNA). Upon static growth in liquid medium, all B. pseudomallei strains produced pellicle biofilms that contained DNA in close association with bacterial cells; however, the ΔbbeS and ΔbbeR strains produced increased biofilms with altered microscopic architecture compared to the wild-type. Unusually, while the ΔbbeS and ΔbbeR single-deletion mutants displayed clear phenotypes, the ΔbbeRS double-deletion mutant was indistinguishable from the wild-type strain. We propose that BbeR-BbeS indirectly affects eDNA secretion and biofilm formation through cross-talk with one or more other TCSTS.

中文翻译:

Burkholderia pseudomallei两组分信号转导系统BbeR-BbeS的破坏导致细胞外DNA分泌增加和生物膜形成改变。

两组分信号转导系统(TCSTS)在原核生物中非常丰富,并调节重要功能,包括耐药性和毒力。革兰氏阴性假单胞菌Burkholderia pseudomallei导致严重的传染病类瘤病,编码136种假定的TCSTS成分。对这些TCSTS进行的计算机分析表明,预测的BbeR-BbeS系统(BPSL1036-BPSL1037)与志贺氏志贺氏菌毒力相关的OmpR-EnvZ渗透调节剂显示出显着的氨基酸序列相似性。为了评估假双歧芽孢杆菌BbeR-BbeS系统的功能,我们通过等位基因交换构建了缺少两个基因的ΔbbeRS双突变株,以及单个ΔbbeR和ΔbbeS突变株。所有这三种突变菌株均以与野生型菌株相同的速率在BALB / c急性类鼻oid病模型中引起疾病​​,在半固体培养基上显示出不变的群体运动,并且在高渗透压培养基上不受影响。但是,当在37°C下培养至少14天时,ΔbbeS和ΔbbeR集落会在相似培养的野生型菌落中形成独特的超粘液形态。在30°C和37°C时,这些超粘液菌株均产生野生型的I型荚膜,但释放的胞外DNA(eDNA)数量增加。在液体培养基中静态生长后,所有假双歧芽孢杆菌菌株均产生包含与细菌细胞紧密结合的DNA的薄膜生物膜。然而,与野生型相比,ΔbbeS和ΔbbeR菌株产生的生物膜增加,且微观结构发生了变化。异常地,虽然ΔbbeS和ΔbbeR单缺失突变体表现出清晰的表型,ΔbbeRS双缺失突变体与野生型菌株没有区别。我们建议BbeR-BbeS通过与一个或多个其他TCSTS的串扰间接影响eDNA分泌和生物膜形成。
更新日期:2020-02-08
down
wechat
bug