根據台灣疾病管制局的資料顯示，病患平均住院一天受院內感染機率約4‰，而在加護病房的病患中，平均住院一天感染機率更高達15‰的可能性，其中又以生物膜造成之感染率最被關注。有鑒於此，許多滅菌及消毒法均廣泛的被應用於醫療器材及環境上之微生物控制處理。然而，這些傳統方法亦隱含其缺點，倘若處理不當，未完全去除之部分微生物便很容易再次滋長，如利用UV紫外線殺菌之法；更可能導致微生物具有抗藥性，如利用化學處理法等。本研究擬利用測試生物性介面活性劑對院內感染常見菌種生物膜之殺菌及抑菌效果，並進一步評估其應用於院內感染環境控制之可行性。研究中選擇了兩株臨床菌株Psedomonas aeruginosa 91P8以及Staphylococcus aureus 920作為實驗菌株，並且將其培養成生物膜，隨後再添加介面活性劑進行生物膜崩解作用，活性劑則選用Rhamnolipid，測試的項目包括不同活性劑濃度以及不同的抑制時間。此外，亦使用一般院內常用殺菌劑如povidone iodine、alcohol、bleach進行生物膜殺菌測試，並檢測殺菌劑與生物性介面活性劑一同作用時之殺菌效能為何。結果顯示，兩株菌之生物膜於16μg/ml Rhamnolipid抑制作用下，均可達到最高減少量約有69.9%以及57%之多；而當同時添加alcohol-Rhamnolipid混合劑對於抑制生物膜比單一使用alcohol約可使其存活度多降低約8%。相同的，使用iodine-Rhamnolipid和hypochlorite-Rhamnolipid 混合劑亦比單一抑制劑作用多降低生物膜存活度約7%及10%。本研究發現當添加生物性介面活性劑與殺菌劑同時抑制生物膜時，對於殺菌與去除生物膜的能力有一定程度的增加，此結果將可提供未來應用於控制院內微生物滋長傳播之可行性，以期減低院內感染之發生。

Taiwan’s CDC (Center for Disease Control and Prevention) has reported that nosocomial infection rate is around 4 % when hospitalized for one day, and up to 15% in the intensive care units while the risk resulting from the contact with biofilm is considered most noteworthy. Although various measures have been adopted to sterilize and disinfect microbes in different pathways, they have not been considered complete and free of concerns. This study was aimed to evaluate the biosurfactant, a redeveloped biological substance, in the inhibition of the microbial growth and to establish a simple system for controlling and monitoring microbes attributable to nosocomial infection. Two clinical strains used in the study, Pseudomonas aeruginosa 91P8 and Staphylococcus aureus 920, were cultivated as biofilm for testing. Rhamnolipid, a biosurfactant, was added into biofilm to evaluate the inhibition efficiency under different concentrations and for different durations. Other disinfectants commonly used in hospital including povidone iodine, alcohol, and hypochlorite, were also used to examine the disinfection capability with co-existence of biosurfactants. In inhibition assay, P. aeruginosa and S. aureus biofilm were reduced by 69.9% and 57.0% of biofilm growth respectively when using 16 μg/ml Rhamnolipid. Use of iodine and biosurfactant mixture reduced the survival percentage of biofilm to zero, in comparison to use only iodine as a single disinfectant. Application of alcohol and hypochlorite decreased the biofilm survival percentage by 7% and 10%, respectively. Our study showed that using the biosurfactant could effectively increase disinfection capability, and therefore reduce the risk of nosocomial infection caused by biofilms in hospitals.

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