Klebsiella pneumoniae分子流行病學及人畜共通病原可能性之探討

Abstract

克雷伯氏肺炎桿菌 (Klebsiella pneumoniae；K. pneumoniae) 是眾所周知的人類病原體。K. pneumoniae以許多不同方式入侵，引起肺炎、尿路感染、肝膿瘍等疾患，為重要性日益增加的社區感染病原菌。文獻報告K. pneumoniae在爬行動物紅腿陸龜有引起肝膿瘍的病例，在其他動物也會造成化膿性感染；於人類活動頻繁的海域，亦有魚類被篩檢出K. pneumoniae的報告。更有研究指出社區型的K. pneumoniae感染引起的肝膿瘍（Klebsiella pneumoniae liver abscess: KLA）已是人類的新興傳染病。研究也發現，從人類疾病檢體分離出的K. pneumoniae臨床菌株，細菌的莢膜和質體及其表現的抗藥性型態，會影響其細菌毒性與致病力。我們的研究目的是利用分子生物學基因分型的相關研究方法，分析由各種動物檢體分離出的K. pneumoniae菌株，其親緣性和致病能力，以了解由動物攜帶的K. pneumoniae是否可能導致人畜共患疾病的潛力。本研究使用分離自人類207株與動物257株的K. pneumoniae菌株，以PFGE進行流行病學的篩選分型，也使用一個源自K. pneumoniae肝膿瘍相關的K2致病菌株CG43的大質體pLVPK衍生物，長度219,385 bp，以及莢膜分型等方法進行基因分型。結果指出，人類原發性K. pneumoniae膿瘍分離株（N = 94）比非膿瘍感染（N = 113）者，有較多是terW+ iutA+ rmpA+ silS+（62％比27％，P < 0.0001）。邏輯式迴歸分析證實存在有terW - rmpA - iutA - silS位點是膿瘍形成的一個顯著危險因素（odds ratio為4.12 ; 95％信賴區間為2.02-8.4，P <0.0001）；而比較由動物分離出的K. pneumoniae與人類臨床感染症病患分離出的四個K. pneumoniae群組，其PFGE相似度可達40%。從人類與爬蟲類動物肝膿瘍分離出K. pneumoniae的案例，發現菌株呈現流行病學的相似性；更進一步，擴大以分子生物學檢測方法，探討包括寵物及野生動物來源的K. pneumonia菌株差異性及親緣關係，結果顯示動物來源與人類來源的肺炎克雷伯氏菌造成的感染疾病，可能有人畜共患潛力。Klebsiella pneumoniae (K. pneumoniae) is a well-known human pathogen, and it is emerging as a pathogen of pyogenic liver abscess in Taiwan during the past two decades. Klebsiella pneumoniae is distributed worldwide and causes a broad spectrum of infections, including pneumonia, septicemia, intra-abdominal infections, urinary tract infections, and meningitis in humans. Similarly, bacterial infections are common in animals, including reptiles, and the frequent occurrence of urinary tract infection in turtles by Klebsiella species was documented. Although K. pneumoniae isolated from infected animals and human may be epidemiologically correlated, few studies were designed to establish the relevance. In this study, we collected 257 K. pneumoniae isolates from non‐repetitive pet animal stool samples and 45 from wildlife animal stool samples. To characterize animal‐carried K. pneumoniae, several panels, including PFGE‐XbaI, K‐type, gyrA PCR‐RFLP, and the presence of pLVPK, was performed to type these isolates at the molecular level. By comparing with clinical K. pneumoniae isolates from human patients, the correlation between pLVPK presence and K. pneumoniae abscess formation, and molecular epidemiology and zoonotic potential of K. pneumoniae were examined. Primary K. pneumoniae abscess isolates (n=94) were more likely to be terW+-iutA+-rmpA+-silS+ than those related to non-abscess infections (n=113) (62% vs. 27%; p<0.0001). Logistic regression analysis indicated that the presence of the terW-rmpA-iutA-silS loci was a significant risk factor (odds ratio, 4.12; 95% confidence interval, 2.02–8.4; p<0.0001) for abscess formation. Despite the overall heterogeneity, K. pneumoniae isolates from animals were genetically related to the pathogenic isolates from human patients, as shown in the group I, II, III, and IV, which had almost 40% similarity on their PFGE‐XbaI pulsotypes. Thsee interesting findings suggested that K. pneumoniae is potentially a zoonotic pathogen.中文摘要---------------------------------------------------i Abstract--------------------------------------------- iii 表目次-------------------------------------------------- vii 圖目次--------------------------------------------------- viii 第一章 緒論---------------------------------------------- 1 　第一節 引言與背景介紹------------------------------------ 1 第二節 文獻探討----------------------------------------- 2 第三節 研究目的----------------------------------------- 19 第二章 肺炎克雷伯菌攜帶的相關性pLVPK衍生位點和膿腫形成---------- 21 　第一節 前言--------------------------------------------- 21 　第二節 材料及方法---------------------------------------- 22 　第三節 結果--------------------------------------------- 25 　第四節 討論--------------------------------------------- 28 第三章 紅腿陸龜所造成的肺炎克雷伯菌肝膿腫---------------------- 44 　第一節 前言--------------------------------------------- 44 　第二節 材料及方法---------------------------------------- 44 　第三節 結果--------------------------------------------- 47 　第四節 討論--------------------------------------------- 49 第四章 肺炎克雷伯氏菌人畜共通疾病---------------------------- 55 　第一節 前言--------------------------------------------- 55 　第二節 材料及方法---------------------------------------- 55 　第三節 結果與討論---------------------------------------- 56 第五章 結論---------------------------------------------- 69 第六章 未來展望------------------------------------------- 72 第七章 參考文獻------------------------------------------- 7