2015-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/656544摘要：鮑氏不動桿菌(Acinetobacter baumannii)近年來在全世界成為重要的院內致病菌之一。其生長條件只需少許營養即可存活，故可在乾燥的環境中存活長達1-5個月之久，導致容易在院內傳播並造成感染。目前歐洲﹑北美﹑亞洲﹑中東﹑澳洲等地都有發生規模不小的不動桿菌群突發。常見不動桿菌感染的臨床表現為肺炎、菌血症、軟組織感染及腦膜炎等。菌血症死亡率在非加護病房病患為16.3%﹑而在加護病房病患死亡率可高達34.0-43.4%。和其他格蘭氏陰性菌菌血症相較，不動桿菌血症的死亡率較高(57% vs. 31-43%, p<0.05)。面對抗生素的壓力，此細菌對各式抗生素快速發展出多重抗藥性，故一旦感染，相當難以治療。國內的研究顯示，有carbapenem抗藥性不動桿菌菌血症的死亡率遠高於無carbapenem抗藥性不動桿菌菌血症的死亡率(46.0% vs. 28.3%, p<0.05)。根據臺大醫院的資料，對傳統5或6種抗生素有抗藥性的不動桿菌菌血症佔所有不動桿菌菌血症的比例，在西元2007, 2008, 2009年，分別為24.9% (54/217), 33.7% (68/202), 32.2% (86/267)。雖然多種抗生素合併治療不動桿菌感染在體外及動物實驗有協同作用及增加存活的結果，但在目前多重抗藥性不動桿菌不斷增加的狀況下，不同抗生素治療療效比較的臨床研究仍稀少，而且受到許多病人的干擾因素所影響。過去研究證實real-time PCR能偵測病人血中菌量且不受病人的其它干擾因素影響，能直接影響病人的預後，而且real-time PCR能不受干擾的反應抗生素是否使用正確。Droplet digital PCR (ddPCR)為新一代的核酸偵測技術，相較於real-time PCR，它可以不依靠標準模版曲線，有更精準的偵測能力且較不受到血中聚合酶鏈鎖反應抑制物的影響。因此本研究將比較ddPCR及real-time PCR用於鮑氏不動桿菌菌血症的定量追蹤，以期找到即時且更佳的鮑氏不動桿菌菌血症追蹤評估方式。<br> Abstract: Acinetobacter baumannii (A. baumannii) have emerged as a serious pathogen in hospital settings worldwide. With the ability to survive on dry inanimate surfaces for 1-5 months and mechanisms to facilitate colonization of patients or medical equipment, A. baumannii propagate easily and cause significant infections in susceptible hosts. Numerous outbreaks of A. baumannii have been documented in Europe, North America, Asia, Middle East, and Australia. In fact, the clinical problem with Acinetobacter species is not only in magnitude, but also severity. Mortality from bacteremia caused by Acinetobacter species is significantly higher than that by other Gram-negative bacteria. Furthermore, mortality from bacteremia caused by carbapenem-resistant Acinetobacter species is significantly higher than that by carbapenem-susceptible Acinetobacter species.Acinetobacter species employ several resistance mechanisms enabling survival under selective antimicrobial pressure, and specific treatment can be further complicated by multidrug resistance. Under the circumstance of increasing multidrug resistance by A. baumannii, despite encouraging results from in vitro and animal studies, only a few clinical studies have compared the outcomes of different antimicrobial regimens, with most of them confounded by multiple co-morbidities of the bacteremic patients. Which antimicrobial regimen is better and would improve the clinical outcome remains unknown in patients with bacteremia caused by these highly resistant Acinetobacter baumannii. Real-time PCR (polymerase-chain-reaction) has been documented to quantify the bacterial load of bacteremia, which can predict a clinical outcome independent to other confounding factors of patients. Bacterial kinetics resulting from real-time PCR analysis also independently predict whether antibiotics use is appropriate or not.Digital PCR is a new method of absolute nucleic acid quantification. Droplet digital PCR has many potential advantages over real-time PCR, including the capability to obtain absolute quantification without external references, exhibits precision that is superior to real-time PCR, and is more tolerant to PCR inhibitors. In order to find a better way to monitor A. baumannii bacteremia, this study compares droplet digital PCR to real-time PCR for quantitative monitoring of A. baumannii bacteremia.