CHARACTERIZATION OF CHRONIC, ASYMPTOMATIC INTESTINAL SHEDDING OF SHIGELLA

这些研究针对的是利用特定克隆的毒力基因。 志贺菌作为DNA探针的区域或其序列信息 聚合酶链式反应检测粪便中志贺氏菌。我们的早期 研究表明，DNA探针非常敏感、快速和有效 在秘鲁腹泻病患者粪便中检测志贺氏菌。 在最近的研究中，利用聚合酶链式反应分析 健康(即无症状)非人类灵长类动物及其健康的粪便 人类照顾者中，我们发现慢性病患病率高，水平低(即 细菌学检测下)志贺氏菌无症状携带。我们的 具体目标是确定(1)这些志贺氏菌是否已完全 毒力潜力，(2)志贺氏菌所处的确切状态 在这些携带者中(例如，在结肠内的粘膜上皮细胞内)， (3)携带者对志贺氏菌的免疫状况，以及(4)如果这种慢性 低水平携带者状态负责维持志贺氏菌 地方性在美国，现在每年有超过25,000个病例。

These studies are directed at utilizing specific cloned virulence gene regions of Shigella as DNA probes or their sequence information in polymerase chain reaction assays to detect Shigella in stools. Our early studies showed that DNA probes were very sensitive, quick, and effective in detecting Shigella in the stool of diarrheal disease patients in Peru. In more recent studies utilizing polymerase chain reaction analysis of stools of healthy (i.e. asymptomatic) nonhuman primates and their healthy human caretakers, we have found a high rate of chronic, low level (i.e. below bacteriologic detection) asymptomatic carriage of Shigella. Our specific objectives are to determine (1) if these Shigella have full virulence potential, (2) the exact state in which Shigella are residing in these carriers (e.g. inside mucosal epithelial cells in the colon?), (3) the immune status of the carrier to Shigella, and (4) if this chronic low level carrier state is responsible for maintaining Shigella endemicity in the U.S. where there are now over 25,000 cases per year.