Genetic Analysis of Mycobacterial Biofilm Formation

描述（由申请方提供）：鸟分枝杆菌复合体（MAC）是在易感人群中引起疾病的最重要的环境分枝杆菌。大多数MAC感染被认为来自稳定的殖民饮用水供应。细菌在水中的主要生活方式是在表面粘附的生物膜中生长，最近的研究表明MAC也不例外。它大量存在于从配水系统中采集的生物膜样品中，并且似乎是这种环境中的优势分枝杆菌物种。遗传学方法已被用于分析生物膜形成的快速增长的模式物种M。然而，MAC形成生物膜的遗传学仍有待探索。使用新开发的遗传和基因组工具，结合MAC生物膜发展的真实实验室模型，我们将进行第一次这样的调查。该探索性项目的具体目标是1）通过使用新的“转座体”诱变方法鉴定参与生物膜形成的早期阶段的MAC基因，和2）通过使用标记诱变和转座子位点杂交鉴定参与成熟的两种生物膜形成的MAC基因。通过建立MAC生物膜形成的遗传分析方法和条件，我们将开始阐明分枝杆菌生物学的一个方面，这是几乎完全未知的。这些结果将提高我们对环境分枝杆菌微生物生态学的理解，并可能导致保护易感人群免受MAC感染的改进方法。

DESCRIPTION (provided by applicant): The Mycobacterium avium complex (MAC) is the most significant of the environmental mycobacteria that cause disease in susceptible humans. Most MAC infections are thought to come from stably colonized drinking water supplies. The predominant way of life for bacteria in water is growth in surface-adherent biofilms, and recent studies have shown that MAC is no exception. It is present in vast numbers in biofilm samples taken from water distribution systems, and it appears to be the dominant Mycobacterium species in such environments. Genetic approaches have been used to analyze biofilm formation by the fast-growing model species M. smegmatis; however the genetics of biofilm formation by MAC remains to be explored. Using newly developed genetic and genomic tools, combined with authentic laboratory models of MAC biofilm development, we will conduct the first such investigation. The specific aims of this exploratory project are 1) to identify MAC genes involved in the early stages of biofilm formation by using a novel "transposome" mutagenesis approach, and 2) to identify MAC genes involved in the formation of mature two-species biofilms by using signature-tagged mutagenesis and transposon site hybridization. By establishing methods and conditions for genetic analysis of biofilm formation by MAC, we will begin to shed light on an aspect of mycobacterial biology that is almost entirely uncharacterized. The results will improve our understanding of the microbial ecology of environmental mycobacteria, and they may lead to improved methods for protecting susceptible people from MAC infection.