Mikroevolution in pathogenen Bakterien

近年来，对序列数据的系统发育分析已经产生了许多令人兴奋和新颖的见解，关于细菌病原体的种群遗传和进化方面。该项目将使用系统发育方法来检测奈瑟氏菌、鼠疫耶尔森氏菌、小肠结肠炎耶尔森氏菌和大肠杆菌的微进化。通过序列分析和DNA-DNA杂交，确定了一种新的奈瑟菌属（目前为奈瑟菌属）与脑膜炎奈瑟菌、淋病奈瑟菌和相关共生奈瑟菌的分类关系。在脑膜炎奈瑟菌和小肠结肠炎耶瑟菌中发现含有异常低水平多态性位点的DNA区域。这些区域将通过群体遗传技术进行调查，如聚结分析，以测试最近是否发生了选择性清除，并确定这种现象的基本性质。将根据IS100的可变插入位点，开发一种基于pcr的鼠疫杆菌精细分型方法，从而实现对古代、中世纪和东方生物变种的识别和细分。将开发大肠杆菌的多位点序列分型（MLST）分类，以使世界各地的实验室能够通过使用一个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.