Mycobacterial determinants of survival and fitness within the bovine host

牛宿主内生存和健康的分枝杆菌决定因素

• 批准号: BB/N004590/1
• 负责人: Sharon Kendall
• 金额: $ 114.9万
• 依托单位: Royal Veterinary College
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FN004590%2F1
• 关键词: Mycobacterial; determinants; survival; fitness; within

Bovine tuberculosis (BTB) is a persistent problem in certain areas of the UK. The current control strategy is to test herds for the presence of BTB at timely intervals and slaughter test-positive animals. However, the observation that BTB is spreading in both geographical area and prevalence suggests that the existing control strategy is not working effectively. The cost of the control programme is £100 million annually, therefore not only is the policy ineffective, it is also a significant economic burden. In addition, BTB can cause tuberculosis in humans, and while this is currently rare, the escalating prevalence of BTB has the potential to develop into a zoonotic (the passage of disease from animals to humans) risk.BTB is caused by a bacterium called Mycobacterium bovis. This is very closely related to Mycobacterium tuberculosis, a bacterium that commonly causes tuberculosis. Tuberculosis in cattle and humans show great similarities and, like the human disease, vaccination is an alternative strategy to control BTB. The vaccine against human tuberculosis is a strain of Mycobacterium bovis called Mycobacterium bovis BCG, however this provides limited protection against the disease in both cattle and humans. Mycobacterium bovis is transmitted by aerosol, once within the animal it enters into cells called macrophages. These cells, normally dedicated to the killing and removal of bacterial pathogens, are unable to kill the bacteria. Instead, Mycobacterium bovis adapts and survives within the lungs in structures called granulomas. However, we do not know much about the genes that allow the bacteria to survive and cause disease in the host. We will knock-out the function of every single gene in the genome of Mycobacterium bovis (approximately 4000) and determine those genes that are required for survival in bovine macrophages and in the whole cow. We will achieve this by using a technique called Transposon Directed Insertion Seqeuncing (TraDIS). This technique has been applied successfully to the study of other bacterial pathogens of medical and veterinary importance, but this will be the first time it has been used to study the genetic determinants of disease in Mycobacterium bovis. We will make libraries of mutants where the function of every gene in the genome has been knocked-out. We will then put the libraries into "screens". Mutants that are recovered after being through a "screen" are compared to the original pre-screened mutant pool by DNA sequencing. Mutants that are unable to survive the screen are identified and as a result we will identify all the genes necessary for survival in the host. Those mutants that are unable to survive in the host represent potential vaccine candidates. We will be able to assess the function of essential genes using a combination of computational analysis, literature searching and comparisons to screens performed on different types of bacteriological media (in vitro). The functions that are essential for survival in the host also reflects the conditions within the host. At the end of this project we will have filled in key gaps in the knowledge of BTB in the area of host pathogen interactions and have identified several potential vaccine candidates to be considered for future development.

牛结核病（BTB）是英国某些地区的一个持续性问题。目前的控制策略是及时检测牛群中是否存在BTB，并屠宰检测阳性的动物。然而，观察到BTB在地理区域和患病率方面都在蔓延，这表明现有的控制战略没有有效地发挥作用。控制方案的费用每年为1亿英镑，因此该政策不仅无效，而且是一个重大的经济负担。此外，BTB可导致人类结核病，虽然目前这是罕见的，但BTB的流行率不断上升有可能发展成为人畜共患病（疾病从动物传播到人类）的风险。BTB是由一种称为牛分枝杆菌的细菌引起的。这是非常密切相关的结核分枝杆菌，一种细菌，通常会导致结核病。牛和人类的结核病表现出极大的相似性，并且与人类疾病一样，接种疫苗是控制BTB的替代策略。针对人类结核病的疫苗是一种称为牛分枝杆菌BCG的牛分枝杆菌菌株，然而这对牛和人类的疾病提供了有限的保护。牛分枝杆菌通过气溶胶传播，一旦进入动物体内，它就进入称为巨噬细胞的细胞。这些细胞通常用于杀死和清除细菌病原体，但无法杀死细菌。相反，牛分枝杆菌适应并存活在肺内称为肉芽肿的结构中。然而，我们对允许细菌存活并在宿主中引起疾病的基因知之甚少。我们将敲除牛分枝杆菌基因组（约4000个）中每一个基因的功能，并确定在牛巨噬细胞和整头牛中生存所需的基因。我们将通过使用一种称为转座子定向插入序列（TRADIS）的技术来实现这一点。该技术已成功应用于其他具有医学和兽医学重要性的细菌病原体的研究，但这将是第一次将其用于研究牛分枝杆菌疾病的遗传决定因素。我们将建立突变体库，其中基因组中每个基因的功能都被敲除。然后我们将把库放到“屏幕”中。通过DNA测序将通过“筛选”后回收的突变体与原始预筛选的突变体库进行比较。不能在筛选中存活的突变体被鉴定出来，因此我们将鉴定出在宿主中生存所必需的所有基因。那些不能在宿主中存活的突变体代表了潜在的疫苗候选者。我们将能够使用计算分析、文献检索和与在不同类型的细菌培养基（体外）上进行的筛选的比较的组合来评估必需基因的功能。在宿主体内生存所必需的功能也反映了宿主体内的条件。在本项目结束时，我们将填补BTB在宿主病原体相互作用领域知识的关键空白，并确定了几种潜在的候选疫苗，供未来开发考虑。

项目成果

A Novel TetR-Like Transcriptional Regulator Is Induced in Acid-Nitrosative Stress and Controls Expression of an Efflux Pump in Mycobacteria.

• DOI: 10.3389/fmicb.2017.02039
• 发表时间: 2017
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Perrone F;De Siena B;Muscariello L;Kendall SL;Waddell SJ;Sacco M
• 通讯作者: Sacco M

Short communication: Pegbovigrastim treatment in vivo does not affect granulocyte ability to migrate to endometrial cells and kill bacteria in vitro in healthy cows.

简短交流：Pegbovigrastim 体内治疗不会影响健康奶牛粒细胞迁移至子宫内膜细胞和体外杀死细菌的能力。

• DOI: 10.3168/jds.2019-16563
• 发表时间: 2019
• 期刊: Journal of dairy science
• 影响因子: 3.5
• 作者: Tombácz K

Isolation and Potential for Transmission of Mycobacterium bovis at Human-livestock-wildlife Interface of the Serengeti Ecosystem, Northern Tanzania.

• DOI: 10.1111/tbed.12445
• 发表时间: 2017-06
• 期刊: Transboundary and emerging diseases
• 影响因子: 4.3
• 作者: Katale BZ;Mbugi EV;Siame KK;Keyyu JD;Kendall S;Kazwala RR;Dockrell HM;Fyumagwa RD;Michel AL;Rweyemamu M;Streicher EM;Warren RM;van Helden P;Matee MI
• 通讯作者: Matee MI

Zoonotic tuberculosis-a call for an open One Health debate.

人畜共患结核病——呼吁开展一场公开的“同一个健康”辩论。

• DOI: 10.1016/s1473-3099(20)30166-3
• 发表时间: 2020
• 期刊: The Lancet. Infectious diseases
• 作者: Zumla A

Re-sensitization of Mycobacterium smegmatis to Rifampicin Using CRISPR Interference Demonstrates Its Utility for the Study of Non-essential Drug Resistance Traits.

• DOI: 10.3389/fmicb.2020.619427
• 发表时间: 2020
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Faulkner V;Cox AA;Goh S;van Bohemen A;Gibson AJ;Liebster O;Wren BW;Willcocks S;Kendall SL
• 通讯作者: Kendall SL