2014-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/645795摘要：李斯特氏菌是一種不產孢子的格蘭氏陽性菌，為一人畜共通傳染病，該菌可於低溫及一般環境中生存，因之容易因食物受到污染而造成群聚感染。一般人受到感染後多為腹瀉，並在幾天之內痊癒，然而在免疫不全的病患中往往造成敗血症或腦膜炎，死亡率可達20%以上。該病原也可經母嬰垂直感染的方式造成早產甚至死胎。在國外是重要的食物傳染的病原體之一。及時釐清各菌株間的基因相關性在疫情調查以及食品衛生管控上相當重要。該菌可分成十三種血清型，其中有四種血清型最容易造成群聚感染。群聚發生則需利用分子分型如脈衝式膠體電泳(PFGE)來釐清，然而該法鑒別度極高，較難應用在辨認發生在不同時空的菌株關聯性以及演化。本實驗室分析1996-2008年間的臺大菌株，發現自2005 年起感染個案有大量增加的趨勢，但PFGE 卻未發現相同的菌株。台灣進來研究亦發現感染的個案近五年有增加的趨勢，但無分子分型亦無食品調查。本研究首先將搜集國內四家醫學中心的菌株，利用DNAsequencebasedtyping(MLST,MVLST)做菌株間基因樹分析，以釐清過去十年間是否有特殊菌株群在台灣散播，所得結果可提供日後本地菌株分型參考，同時針對新診斷個案進行問卷訪察及針對可疑食品培養菌株，希望找出本地傳播源以利疫情控制。<br> Abstract: Listeria monocytogenes is a Gram-positive, facultative anaerobic, non–spore-formingbacillus that exists in contaminated food or animal products causing invasive diseases.Clinical presentations of human listeriosis include self-limiting gastroenteritis, commonlyseen in outbreaks, spontaneous abortion in pregnant women, and severe invasive infections(sepsis or meningitis) in immunocompromised patients and in elderly patients with high casefatality rate (>20%).Epidemiologic investigations could be carried out by several methods to define geneticrelatedness. Serotyping is a commonly used method but only 13 serotypes could bediscriminated. Among them, serotypes 1/2a, 1/2b, 1/2c, and 4b are associated with the vastmajority of human diseases. Pulsed-field-gel electrophoresis (PFGE) is the standard methodfor outbreak surveillance, but it provided little information on the phylogenic relationshipsamong strains. Strains from a presumed ancestor in different geographic and temporallyoutbreak would not be identified by PFGE. Sequence-based methods could provide moreinformation about phylogeny and define clonal framework. Currently MLST and MVLSThave been used for large-scale epidemiologic investigations.Outbreaks of L. monocytogenes infections have occurred in European countries, NorthAmerica, and Japan but rarely described in other Asian countries. In our previous study(1996-2008), an upsurge of cases as noted since 2005 in our institute. However, the results ofPFGE analysis in our study failed to identify clustering of cases. Other studies from Taiwanalso noticed an increase of cases in recent 5 years, but none of them provided informationabout molecular typing. Emergence of some epidemiologic clones or evolved from a certainvirulent clone might occur in recent years in Taiwan. Hence, we would use DNA sequencebased methods to investigate isolated collected from four medical centers in Taiwan insteadof PFGE. Furthermore, no specific food vehicle has been identified in Taiwan. We wouldfollow newly diagnosed cases using a standard questionnaire and food material surveillance toidentify possible vehicles that transmit listeriosis in Taiwan. Our results would provide datafor better controlling listeriosis in Taiwan.