2020-11-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/713546克雷伯氏肺炎桿菌為重要病原菌，引起社區性感染如化膿性肝膿瘍、肺炎，除此之外，克雷伯氏肺炎桿菌也是院內感染重要的致病菌(約10%)，由於多重抗藥性菌株的增加已成為臨床上重要的問題，除了廣效性乙內醯胺酶(Extended-spectrum β-lactamase; ESBL)的盛行，進一步抗碳氫黴烯類的菌株(Carbapenem-resistant K. pneumoniae; CRKP)更逐年增加。莢膜型K1 和 K2 是造成社區型化膿性肝膿瘍克雷伯氏肺炎桿菌最主要且具高致病力的菌株，我們經由菌株分型和之前的研究發表皆發現K1、K2、K5、K20、K54 及 K57 是在台灣造成社區型化膿性肝膿瘍和肺炎菌株的6種主要莢膜型。K64是抗碳氫黴烯類菌株最主要的莢膜型，約佔38%。而最近許多研究顯示，在亞洲地區除了莢膜型K64之外，K47是抗碳氫黴烯類菌株最常見的莢膜型。由於本實驗室與中研院的研究發現K1與K2莢膜接合疫苗，可有效保護免疫力正常的老鼠。然而，K64莢膜接合疫苗在小鼠無法誘發莢膜多醣抗體的產生。因此本計畫擬分離K5、K20、 K54、 K57 與 K47莢膜型噬菌體，表現莢膜分解酵素，利用酵素分解莢膜多醣，找出抗原性最好的多醣長度，並以適合的攜帶蛋白質接合成莢膜多醣疫苗，在給予cyclophosphamide之免疫力降低小鼠，完成疫苗的安全性、免疫誘發性與保護力評估，以確認疫苗在易感染多重抗藥性菌株的免疫力不全病人之保護效果，如果成功則進入疫苗開發的後續實驗。長程的目標將是發展多價莢膜多醣疫苗，以提高預防克雷伯氏肺炎桿菌的感染效果。由於K1與K2莢膜接合疫苗已完成技轉，本計劃可延長此疫苗之專利期並且擴大專利佈局。 Klebsiella pneumoniae is an important pathogen causing community-acquired infections such as pyogenic liver abscess (PLA) and pneumonia. Besides, K. pneumoniae is also responsible for approximate 10% of nosocomial infections and increasing resistances to antibiotics such as extended-spectrum -lactams and carbapenem. Strains with the K1 and K2 capsular types have been identified as the predominant virulent types (60-85%) in K. pneumoniae PLA. Our preliminary data are consistent with some previous findings and indicated that K1, K2, K5, K20, K54 and K57 are the six predominant capsular types of PLA and pneumonia strains in Taiwan. The capsular type K64 accounted for 32/85 (38%) carbapenem-resistant K. pneumoniae (CRKP) strains, was the most prevalent type of CRKP in Taiwan. Several recent studies indicated that, besides K64, K47 is also the common capsular type of CRKP strains in Asia. The recent results of our lab collaborated with Academia Sinica demonstrated that K1 and K2 capsule polysaccharide (CPS) conjugate vaccine could protect mice from subsequent infection of K. pneumoniae K1 and K2 strain. However, the K64 CPS conjugated vaccine failed to induce production of anti-CPS antibody. Therefore, in this project, we will isolate K5, K20, K54, K57 and K47 bacteriophages. Then, the capsule depolymerases will be expressed. The CPS fragments digested by the enzymes with best antigenicity will be selected and conjugated with a carrier protein to generate CPS conjugated vaccines. The safety, immune response and protection efficacy in cyclophosphamide treated mice mimic immuno-compromised hosts will be evaluated. When the protection efficacy in immuno-compromised mice was demonstrated, we will proceed to the pre-IND development. The development of a polyvalent capsule conjugate vaccine for prevention of K. pneumoniae infections will be our log-term goal. As the technology transfer of the K1 and K2 CPS conjugate vaccine has been fulfilled, this project will prolong the patent period of this conjugate vaccine and expand our patent portfolios.克雷伯氏肺炎桿菌抗碳氫黴烯類克雷伯氏肺炎桿菌莢膜多醣接合疫苗Klebsiella pneumoniaecarbapenem-resistant K. pneumoniaecapsule polysaccharideconjugate vaccine