Rapid characterization of mycobacteria and drug resistance in paucibacillary TB

少杆菌结核病中分枝杆菌和耐药性的快速鉴定

基本信息

批准号：
7268101
负责人：
BLANCA I RESTREPO
金额：
$ 18.02万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-06-15 至 2009-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7268101
关键词：
Rapid characterization mycobacteria drug resistance

项目摘要

DESCRIPTION (provided by applicant): Global challenges to tuberculosis (TB) control are multidrug-resistance (MDR-TB; a NIAID Category C Priority Pathogen under Biodefense Agenda) and the increased susceptibility of populations such as elderely, HIV infection, type 2 diabetes and other immunosuppressive chronic diseases. We propose to exploit our established study sites both sides of the south Texas/Mexico border and in Medellin, Colombia, where rates of MDR-TB and type 2 diabetes are high. We will use our recently developed extraction/real time PCR (qPCR) techniques to study the pathogenesis of TB and evolution of MDR-TB in these populations. Our initial emphasis will be on paucibacillary disease such as extrapulmonary TB (EPTB) and smear negative pulmonary TB (PTB). In aim 1 we examine the potential of our highly sensitive and specific qPCR for TB DNA to improve the detection of MTB as well as to quantitate its distribution in several different cellular and physiologic compartments. This non-invasive technique has the ability to determine the number of gene copies, cellular location and nature (intact or lysed) of mycobacteria in pulmonary and extra- pulmonary specimens. It is also sufficiently sensitive to detect mycobacterial DNA in specimens from paucibacillary TB, including MDR-TB, where diagnosis and pathogenesis are major challenges. In Aim 2 we adapt our qPCR method using molecular beacon probes for detection of mutations to rifampicin (RIF) as the first step in developing a rapid direct indicator of MDR-TB in pulmonary and extrapulmonary specimens. Finally we will explore the feasibility of refining the detection of resistance mutations by qPCR from the current qualitative "presence" or "absence" of resistance, to quantification of the ratio of RIF-resistant to sensitive bacteria. This approach will provide a means to study the evolution of resistance in patients who may be infected with mixed populations of resistant and sensitive MTB. We are particularly interested in this respect in patients with diabetes who we have shown to be particularly susceptible to recurrent disease with MDR-TB. The PI is an Assistant Professor working in a medically underserved community, characterized by low rates of HIV-co-infection, but high rates of type 2 diabetes. Funding of this R21 is critical to generate preliminary data that will strengthen future, more complex studies of the pathogenesis and evolution of MDR- TB in high-risk populations.

描述（由申请人提供）：全球对结核病（TB）控制的挑战是多药耐药性（MDR-TB；在生物脱脂式议程下的C Priority病原体）和人群的易感性增加，例如老年人，HIV，HIV，HIV感染，2型糖尿病型糖尿病和其他免疫抑制性慢性疾病。我们建议利用我们已建立的研究地点的两侧，南德克萨斯州/墨西哥边境和哥伦比亚的麦德林，那里的MDR-TB和2型糖尿病率很高。我们将使用最近开发的提取/实时PCR（QPCR）技术来研究这些人群中TB的发病机理和MDR-TB的进化。我们最初的重点将放在paucibacillary疾病上，例如肺外结核（EPTB）和涂片阴性肺结核（PTB）。在AIM 1中，我们检查了高度敏感和特异性QPCR对TB DNA的潜力，以改善MTB的检测，并在几个不同的细胞和生理室中定量其分布。这种非侵入性技术具有确定肺和肺部标本中分枝杆菌基因拷贝数，细胞位置和性质（完整或裂解）的数量。在包括MDR-TB在内的PAUCIBACILLARY TB的标本中检测分枝杆菌DNA也足够敏感，其中诊断和发病机理是主要的挑战。在AIM 2中，我们使用分子信标探针调整了QPCR方法，以检测突变对利福平（RIF），作为在肺和肺外样品中开发MDR-TB快速直接指示的第一步。最后，我们将探索QPCR从当前的定性“存在”或“不存在”抗性的可行性，从抗RIF耐药性与敏感细菌的比率定量。这种方法将提供一种研究可能感染耐药和敏感MTB混合群体的患者的耐药性演变的方法。对于糖尿病患者，我们对这一方面特别感兴趣，我们证明他们特别容易患有MDR-TB的复发性疾病。 PI是在医疗服务不足的社区工作的助理教授，其特征是HIV-CO感染率较低，但2型糖尿病的发生率很高。该R21的资金对于生成将增强未来的初步数据至关重要，对高危人群中MDR-TB的发病机理和演变的更复杂研究。