Molecular typing of Mycobacterium leprae

描述（申请人提供）：1991年世界卫生大会的一个目标是到2000年消除麻风病这一公共卫生问题。目标是将麻风病发病率降至每10 000人中不到1人。尽管实施了多种药物治疗方案，但在占全球麻风病例80%以上的最流行国家，这一目标尚未实现。发现的新病例数也没有减少，表明致病剂麻风分枝杆菌的传播尚未得到控制。 在对传播的理解方面存在根本性的差距，并且缺乏追踪麻风病的敏感方法。关于M.麻风病、感染途径和传播方式。为了解决这些问题，M.麻风是基于基因组序列的可用性和多位点可变数目串联重复序列分析（MLVA）的原理提出的，MLVA已被开发用于几种其他感染性生物。M.麻风不能在实验室中培养，用于研究应用的细菌主要来自易感的犰狳或裸鼠。因此，这项试点研究的设计有两个具体目标：1。一个标准的分子分型方法的发展，使用一组犰狳衍生的M。麻风分离株和2.优化方法在一组M.麻风病患者的活检和鼻拭子中提取的DNA。该方法包括PCR扩增每个M分离株的含有短串联重复序列的多个基因组位点。并将每个位点的片段长度与从其它分离株获得的片段长度进行比较。将使用自动电泳、数据收集和分析。本研究的长期目标是为未来的流行病学研究提供合适的工具和技术，如人源、非人源和环境源对M.麻风经鼻或经皮途径传播和病原体释放以及患者复发与再感染的鉴别。

DESCRIPTION (PROVIDED BY APPLICANT): An objective of the 1991 World Health Assembly was the elimination of leprosy as a public health problem by the year 2000. The goal was to achieve a reduction in prevalence of leprosy to less than 1 per 10,000 population. This goal has not been achieved in the most endemic countries, where more than 80% of the global leprosy cases occur, despite the implementation of the Multi Drug Therapy (MDT) program. The number of new cases detected has also not reduced indicating that the transmission of the causative agent Mycobacterium leprae has not been controlled. There are fundamental gaps in the understanding of transmission, and a lack of sensitive methods to track leprosy. Questions remain regarding the nature of the reservoir of M. leprae, the route of infection, and mode of its spread. To address these concerns, a DNA typing method for M. leprae is proposed based on the availability of the genome sequence and the principle of multiple locus variable-number of tandem repeat analysis (MLVA), which has been developed for several other infectious organisms. M. leprae cannot be cultivated in a laboratory and bacteria for research applications is mainly derived from susceptible armadillo or nude mice. This pilot study is therefore designed with two specific aims: 1. Development of a standard molecular typing method using a panel of armadillo derived M. leprae isolates and 2. Application of the optimized methods in a panel of M. leprae DNA derived from biopsies and nasal swabs from patients. The methods involve the PCR amplification of multiple genomic loci containing short tandem repeats for each isolate of M. leprae and the comparison of the fragment length of each locus with that obtained from other isolates. Automated electrophoresis, data collection and analysis will be used. The long-term goal of the study is to provide the tools and techniques suitable for future epidemiological studies such as the role of human, non-human and environmental sources of M. leprae in the transmission of leprosy via nasal or dermal routes of ntry and release of the pathogen and the differentiation of relapse from reinfection in patients.