DRUG RESISTANCE AND GENE TRANSFER IN H PYLORI

描述(改编自申请人的摘要)：这是一份修订后的 幽门螺杆菌分子遗传学研究的应用程序版本 (惠普)。伯格博士对前一版本的批评做了大量的工作 他已经准备好了本质上是一个全新的东西 申请。因此，他没有详细回应之前的 批评，不需要再多说了。本申请 重点关注幽门螺杆菌新出现的抗生素耐药性和 在物种内部进行广泛的遗传交流的可能性。伯格博士 注意到惠普在以下方面表现出显著的基因多样性 指纹标记以及特定的蛋白质 与致命性有关。这种多样性的分子基础是， 然而，尚不清楚，尽管已经观察到Hp分离株是 经常变形，通常是高度变形的，并可以参与DNA 活体内交换。正如可能预期的那样，对 克拉霉素(CLA)和甲硝唑(Met)是两种广泛使用的药物，已 一直在上升，特别是在第三世界，这些毒品 不加区别地使用。无论是抵抗的机制，还是 到目前为止，已经确定了负责的基因。 伯格博士有两个具体目标，即识别和描述 共轭亚油酸和甲硫氨酸抗性基因及遗传分析 幽门螺杆菌在体内的重组。在初步研究中， 他建立了用于基因分型的随机扩增多态性DNA和聚合酶链式反应-限制性片段长度多态性方法 HP，并表明这些方法比MLEE更敏感，并且 这种质粒的可变性并不是不成比例的。 到了分型的特异性。他还展示了随机扩增多态性DNA在系谱分析中的作用 对实验室K12菌株进行了分析，观察到的变异是 通常在复制末端或其附近，可能是由于 在末端的复制复合体，储存在STAB上的菌株。使用 关于幽门螺杆菌，伯格博士已经证实感染了多个幽门螺杆菌 一株确诊的关节多发性感染病例 GnotoBioticlet模型-这似乎是HP的一个非常好的模型 感染。最后，他构建了一个有序的宇宙中子库 68个单位，有3个缺口，发现基因的顺序相当 与PFGE定位的不同菌株不同。

DESCRIPTION (Adapted from applicant's abstract): This is a revised version of an application to study the molecular genetics of H. pylori (Hp). Dr. Berg took the critique of the previous version so much to heart that he has prepared what is in essence an entirely new application. Therefore, he has not responded in detail to the previous critique and no more need be said about it. The present application is focussed on emerging antibiotic resistance in Hp and on the possibility of extensive genetic exchange within the species. Dr. Berg notes that Hp shows a remarkable genotypic diversity with respect to fingerprinting markers as well as specific proteins such as those implicated in virulence. The molecular basis for this diversity is, however, unknown, though it has been observed that Hp isolates are frequently transformable, often highly so, and could engage in DNA exchange in vivo. As might have been expected, resistance to clathromycin (Cla) and metronidazole (Met), two widely used drugs, has been on the rise, especially in the third world, where these drugs are used indiscriminately. Neither the mechanisms of resistance nor the responsible genes have been identified to date. Dr. Berg has two specific aims, namely to identify and characterize the genes for Cla and Met resistances and to analyze genetic recombination among Hp strains in vivo. In preliminary studies, he has developed the RAPD and PCR-RFLP methods for genotyping of Hp,and shown that these methods are more sensitive than MLEE, and that plasmid variability does not contribute disproportionately to typing specificity. He also showed that RAPD was useful for pedigree analysis of laboratory K12 strains and that observed variations were often at or near the replication terminus, possibly owing to decay of the replication complex at the terminus in strains stored on stabs. With respect to Hp, Dr. Berg has demonstrated infection with multiple Hp strains and confirmed joint multiple infection in a gnotobioticpiglet model - which appears to be a very good model for Hp infection. Finally, he has constructed an ordered cosmid library of 68 units with 3 gaps, and found the order of genes to be quite different from that in a different strain mapped by PFGE.