Biological, Epidemiological and Clinical Studies on Amebic Infection among Institutionalized Populations

尝试对机构中的居民进行流行病学和临床研究，这些居民支持溶组织内阿米巴的高感染率。对这些个体的阿米巴分离物也进行了生物学分析。流行病学分析表明，特异性抗原检测法和常规粪检阳性率高达30%。然而，大多数感染者似乎是由于持续的无症状感染溶组织埃希氏菌所致。从这些持续感染的个体中分离出的几株溶组织埃希氏菌具有与溶组织埃希氏菌一致的遗传和抗原性；然而，通过灵敏的荧光方法检测，它们对组织培养细胞几乎没有毒力。根据几丁质酶基因等4个不同基因的碱基序列多态性，对溶组乳杆菌亚群的遗传类型进行了鉴定，并将其应用于几个研究所的…分离株更多的挑战。分析表明，来自单个机构的分离株具有完全相同的基因类型，表明只有一个感染个体对阿米巴感染的扩大负责。进一步的研究表明，少数感染率较高的机构的基因类型与神奈川县首次暴发时检测到的基因类型完全相同，并表明一名感染者已从神奈川的机构转移到这些新机构。该方法也适用于从国外虱子分离的阿米巴分离物。然而，在这些国外分离株和国内分离株之间几乎没有检测到重合。同时，对非致病性阿米巴进行了无菌培养试验，最终设计出一种新型的伊格达-S培养基，实现了这种阿米巴的完全无菌培养。对阿米巴分离株的生物学特性进行了研究，发现了几种新的阿米巴抑制剂。这些抑制剂作为药物开发的先导化合物的可能性将被调查。用叙利亚金黄地鼠颊囊制作脓肿形成实验模型。较少

Epidemiological and clinical studies were attempted for residents in institutions, who shoed high infection rates with Entamoeba histolytica. Biological analyses were also conducted on the ameba isolates from such individuals. The epidemiological analyses demonstrated as high as 30% positive rate by the specific antigen detection method and the conventional stool examination. However, most of the infected seemed to be due to the persistent asymptomatic infections with E.histolytica. Several strains of E.histolytica isolated from such individuals with the persistent infection showed genetic and antigenic properties consistent with those of E.histolytica ; however, they did show virtually no virulence against tissue-cultured cells as examined with a sensitive fluorescent method. Based on the base sequence polymorphism of 4 different genes like chitinase gene, identification of genetic types of subpopulations of E.histolytica was developed, and applied to the isolates from several institu … More tions. The analyses demonstrated that the isolates from a single institution showed entirely the same genetic type, suggesting that only single infected individual is responsible for expansion of the amebic infection.Further studies indicated that the gene type at a few institutions with rather high infection rates was exactly the same as that detected in the fist outbreak in Kanagawa Prefecture, and demonstrated that an infected individuals had moved from the institute in Kanagawa to these new institutions. This method was also applied to the ameba isolates from foreign countries lice Thailand. However, virtually no coincidence was detected between these foreign isolates and domestic strains. Trials of axenic cultivation of Entamoeba dispar, nonpathogenic ameba, was also actively conducted, which finally resulted in a newly designed YIGADHA-S medium, which allowed complete axenic cultivation of this ameba. Biological characterization of ameba isolates was also attempted by examining the process of excystation and sulfur containing amino acid metabolism, which resulted in discovery of several novel inhibitors. The possibility of these inhibitors as lead compounds for drug development will be investigated. The experimental model for abscess formation was produced by using a Syrian golden hamster cheek pouch. Less