COMPARATIVE GENOME ANALYSIS OF SALMONELLA SPECIES

肠道细菌有相关的管家基因， 染色体顺序 沙门氏菌和大肠杆菌之间的DNA差异。 大肠杆菌中的序列似乎是在岛内聚集在一起的序列， 非同源的DNA。 这些岛屿似乎包含了大部分的 参与发病机制的基因， 致病岛，虽然它们的起源，传播方式， 它们到底包含什么仍然是个谜 有两个主要目标 在这个提议中。 一个是识别那些 区分各种沙门氏菌（具有不同的宿主偏好）， 彼此，从E。大肠杆菌和其他肠道细菌。的另一部分 其目的是构建缺失岛的沙门氏菌衍生物， 包含岛中的突变，然后表征表型 的衍生菌株的各种毒力测定。 第二个主要目的是确定基因重排的作用 in S.伤寒，如果有的话。 S.伤寒和部分沙门氏菌。副伤寒可引起伤寒 发烧 作者观察到，这些人类适应菌株经历了 高频率的基因重组 在文化中， 从未观察到重排。 作者认为 重排与细胞生长有关， 这个假设。

Enteric bacteria have related house keeping genes in about the same chromosomal order. The DNA differences between say Salmonella and E. coli appear to be sequences which are clustered together within islands of non-homologous DNA. These islands appear to contain most of the genes that are involved in pathogenesis and have been called pathogenicity islands although their origin, means of transmission, and precisely what they contain remain a mystery. There are two major aims in this proposal. One is to identify the loops or islands that distinguish various Salmonella (with different host preferences) from each other, from E. coli, and from other enteric bacteria. Also part of this aim is to construct Salmonella derivatives missing the islands or containing mutations in the islands and then characterize the phenotype of the derivative strains by a variety of virulence assays. The second major aim is to determine the role of genetic rearrangement in S. Typhi, if any. S. typhi and some S. Paratyphi can cause typhiod fever. The authors observed that these human adapted strains undergo genetic rearrangement at high frequency. In culture the same kinds of rearrangements have never been observed. The authors believe that the rearrangements are associated with growth in cells and will investigate this hypothesis.