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。淋球菌感染具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”的社会或地理上确定的社区。这些“核心群体”被认为是社区内感染持续传播的宿主，因此，了解构成生物的生物学性质对公共卫生控制战略很重要。我们建议研究淋病奈瑟菌在一个社区内随着时间的推移和与宿主个体有关的流行病学信息的分子进化。这是两位淋病传染病和流行病学专家以及一位人口遗传学家的合作成果。两种分子分型方法将用于鉴定淋球菌分离物：por基因测序和多位点序列分型（MLST）方案，其中6个管家基因的等位基因通过测序约500 bp的基因内部片段来鉴定。该研究有三个主要目标：第一是确定20年来马里兰州巴尔的摩一个高流行社区淋病奈瑟菌种群遗传结构的时间趋势。第二是将种群遗传参数的变化与宿主个体在“核心”或“外围”地区居住的流行病学信息联系起来。我们的主要假设是，较高的遗传多样性水平、较强的贫基因选择压力、正增长率和较高的重组率相对于外围群体将表征核心淋病奈瑟菌的群体遗传结构。第三个目的是确定性别、年龄或播散性感染与局部感染是否会影响淋病奈瑟菌的种群遗传结构。

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.