CHARACTERIZATION OF CHRONIC, ASYMPTOMATIC INTESTINAL SHE

这些研究旨在利用特定的克隆志贺氏菌毒力基因区域作为DNA探针或其序列信息在聚合酶链反应试验中检测粪便中的志贺氏菌。我们的早期研究表明，DNA探针在秘鲁腹泻病患者粪便中检测志贺氏菌非常敏感、快速和有效。在最近的研究中，利用聚合酶链反应分析健康（即无症状）的非人灵长类动物及其健康的人类照顾者的粪便，我们发现慢性、低水平（即低于细菌学检测）无症状携带志贺氏菌的比例很高。我们的具体目标是确定(1)这些志贺氏菌是否具有完全的毒力潜力，(2)志贺氏菌在这些携带者中驻留的确切状态（例如在结肠粘膜上皮细胞内？），(3)携带者对志贺氏菌的免疫状态，以及(4)这种慢性低水平携带者状态是否负责维持志贺氏菌在美国的地方性，目前每年有超过25,000例病例

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