Mikroevolution in pathogenen Bakterien

近年来，对序列数据的系统发育分析在细菌病原体的种群遗传和进化方面产生了许多令人兴奋和新颖的见解。这个项目将使用系统发生学方法来研究奈瑟氏菌、鼠疫耶尔森菌、小肠结肠炎耶尔森菌和大肠杆菌的微进化。通过序列分析和DNA-DNA杂交，将确定一个新种的分类关系，包括脑膜炎奈瑟氏菌、淋病奈瑟氏菌和相关共生奈瑟氏菌。在脑膜炎奈瑟氏菌和小肠结肠炎耶尔森氏菌中发现了含有异常低水平多态位点的DNA区域。这些区域将通过群体遗传学技术进行调查，如合并分析，以测试最近是否发生了选择性扫描，并确定此类现象的基本特性。基于IS100的可变插入位点，将开发一种基于聚合酶链式反应的鼠疫杆菌精细分型方法，从而能够识别和细分生物群安提瓜、中世纪和东方。将对大肠杆菌进行多位点序列分型(MLST)分类，以使世界不同地区的实验室能够通过使用共同的分类系统进行互动。

In recent years, phylogenetic analyses of sequence data have yielded numerous exciting and novel insights on population genetic and evolutionary aspects of bacterial pathogens. This project will use phylogenetic methods to examine microevolution in Neisseria, Yersinia pestis, Yersinia enterocolitica and Escherichia coli. The taxonomic relationships of a new Neisseria species, currently N. spp., will be defined relative to N. meningitidis, N. gonorrhoeae and related commensal neisseriae by sequence analysis plus DNA-DNA hybridization. DNA regions containing unusually low levels of polymorphic sites have been found in N. meningitidis and Y. enterocolitica. These regions will be investigated by population genetic techniques such as coalescence analysis to test whether selective sweeps have recently occurred, and to determine the basic properties of such phenomena. A PCR-based, fine typing method will be developed for Y. pestis based on the variable insertion sites of IS100 that will enable recognition and subdivision of the biovars antiqua, medievalis and orientalis. A multilocus sequence typing (MLST) classification will be developed for E. coli in order to enable laboratories in different parts of the world to interact by using a common classification system.