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）：结核病 (TB) 控制的全球挑战是多重耐药性（MDR-TB；生物防御议程下的 NIAID C 类优先病原体）以及老年人、HIV 感染、2 型糖尿病等人群易感性增加和其他免疫抑制性慢性疾病。我们建议利用我们在德克萨斯州南部/墨西哥边境两侧以及哥伦比亚麦德林建立的研究基地，那里的耐多药结核病和 2 型糖尿病发病率很高。我们将使用我们最近开发的提取/实时 PCR (qPCR) 技术来研究这些人群中结核病的发病机制和耐多药结核病的演变。我们最初的重点是少杆菌疾病，例如肺外结核 (EPTB) 和涂片阴性肺结核 (PTB)。在目标 1 中，我们研究了针对 TB DNA 的高灵敏度和特异性 qPCR 的潜力，以改进 MTB 的检测以及定量其在几个不同细胞和生理区室中的分布。这种非侵入性技术能够确定肺和肺外样本中分枝杆菌的基因拷贝数、细胞位置和性质（完整或裂解）。它还具有足够的灵敏度来检测少杆菌结核（包括耐多药结核）样本中的分枝杆菌 DNA，而耐多药结核的诊断和发病机制是主要挑战。在目标 2 中，我们调整了 qPCR 方法，使用分子信标探针检测利福平 (RIF) 突变，作为开发肺部和肺外标本中耐多药结核病快速直接指示剂的第一步。最后，我们将探讨将qPCR检测耐药突变从目前定性“存在”或“不存在”耐药，细化到RIF耐药菌与敏感菌比例的定量的可行性。这种方法将提供一种方法来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。我们对糖尿病患者特别感兴趣，我们已证明这些患者特别容易患耐多药结核病复发。 PI 是一名助理教授，在医疗服务匮乏的社区工作，该社区的特点是 HIV 合并感染率较低，但 2 型糖尿病发病率较高。 R21 的资助对于生成初步数据至关重要，这些数据将加强未来对高危人群中耐多药结核病发病机制和演变的更复杂的研究。