Molecular Epidemiology of N. gonorrhoeae

淋病是一种常见的细菌感染，主要通过性接触传播。淋球菌感染有一种流行病学模式，其特点是感染集中在被称为“核心群体”的社会或地理定义的社区。这些“核心群体”被提议作为社区内感染持续传播的蓄水池，因此，了解构成生物的生物学性质对于公共卫生控制战略非常重要。我们建议研究奈瑟氏菌淋病在一个群体内随时间的分子进化，以及与宿主个体相关的流行病学信息。这是两位传染病和淋病流行病学专家和一位人口遗传学家共同努力的结果。将使用两种分子分型方法：POR基因测序和多位点序列分型(MLST)方案，其中6个看家基因的等位基因是通过对大约500bp的基因内部片段进行测序来表征的。这项研究有三个主要目标，第一个是确定马里兰州巴尔的摩一个高流行社区20年来淋病人群遗传结构的时间趋势。第二种方法是将人口遗传参数的变化与宿主个人在“核心”或“外围”地区的住所有关的流行病学信息联系起来。我们的主要假设是，相对于外围种群，更高水平的遗传多样性、更强烈的POR基因选择压力、正增长率和更高的重组率将是淋病核心种群遗传结构的特征。第三个目标是确定性别、年龄或播散性感染与局部感染是否影响淋病人群的遗传结构。

Gonorrhea is a common bacterial infection that is transmitted primarily by sexual contact. Gonococcal infections have an epidemiological pattern characterized by the concentration of infections in social or geographically defined communities termed "core groups". These "core groups" have been proposed as reservoirs for the continued transmission of infections within communities, and therefore, understanding the biological nature of the constituent organisms is important for public health control strategies. We propose to examine the molecular evolution of Neisseria gonorrhea within a community over time and in relation to epidemiological information pertaining to the host individuals. This is a collaborative effort between two experts in infectious disease and epidemiology of gonorrhea and a population geneticist. Two molecular typing methods will be used to characterize gonococcal isolates: por gene sequencing and multi-locus sequence typing (MLST) scheme, in which alleles at six housekeeping genes are characterized by sequencing approximately 500 bp internal fragments of the genes. The study has three main objectives The first is to determine temporal trends in the population genetic structure of N. gonorrhea over a 20-year period in a high prevalence community, Baltimore, MD. The second is to correlate changes in population genetic parameters with epidemiological information pertaining to the host individual's residence in a "core" or "peripheral" region. Our major hypothesis is that higher levels of genetic diversity, more intense selection pressure on the por gene, a positive growth rate, and a higher recombination rate relative to the peripheral population will characterize the population genetic structure of N. gonorrhea in the core. The third aim is to determine whether gender, age, or disseminated versus local infection influences the population genetic structure of N. gonorrhea.