創傷覆蓋材之抗菌效能評估方法探討   全文下載

The Discussion of Antibacterial Efficacy Evaluation Methods in Wound Dressings

創傷覆蓋材是用於覆蓋傷口之無菌或非無菌醫療器材，具有吸收傷口分泌物、避免擦傷、摩擦、乾燥及污染等功能。創傷覆蓋材如宣稱可抗菌或抑菌，則應檢附抗菌試驗（Anti-Bacterial Test）或抑菌試驗（Bacteriostasis Test）評估資料。鑑於創傷覆蓋材產品設計多元、國際間相關抗菌試驗方法繁多，為了解方法差異及適用性，本研究進行相關國際標準方法探討，評估影響方法適用性關鍵因素，以歸納出適用範圍較廣之創傷覆蓋材檢測方法。經彙整創傷覆蓋材之抗菌試驗可分為定性及定量兩部分，在定性試驗方面，測試原理多以觀察產品是否可抑制細菌生長或於培養基生成抑菌圈，作為判斷依據，衛生福利部食品藥物管理署（下稱食藥署）108年評估結果發現影響方法適用性的因素包括：測試菌液濃度、產品材質及抗菌成分能否有效釋出等。在定量試驗方面，測試原理則多將定量檢體與測試菌液共同培養一定時間後，與對照組比較，計算檢體之減菌率。本次分別以AATCC TM100及ASTM E2149-20進行測試比較，結果顯示7個以AATCC TM100測試之檢體，1個因材質無法吸收菌液，致無法評估外，僅2個檢體可達>99.99%減菌率；9個以ASTM E2149-20測試之檢體，8個可達>99.99%減菌率，推測ASTM E2149-20方法係將檢體完全浸入菌液，且過程中經振盪步驟，有助於提高菌液與檢體接觸機率及抗菌成分釋出，顯示產品材質及抗菌成分有效釋出同樣是影響方法適用性之因素。

Wound dressings are non-sterile or sterile medical devices, which can absorb exudates, protect the wound from infection and friction, and maintain an adequate moist environment by covering the wounds. These products may claim bacteriostatic or antibacterial efficacy and should provide related test results as evidences. Owing to the variety of wound dressings and different methods for evaluating antibacterial efficacy, this study aimed to test various methods, summarize key factors that may affect antibacterial efficacy, and select the method suitable for most products on the market. Antibacterial efficacy can be tested either qualitatively or quantitatively. Qualitative antibacterial efficacy is evaluated by observing the growth inhibition or formation of inhibition zones of microorganisms. Based on our research in 2019, the suitability of qualitative antibacterial efficacy method is depending on the concentration of bacterial suspension, the release effectiveness of antibacterial agents under the product’s material, and structure design. When it comes to quantitative antibacterial efficacy tests, the efficacy is shown as bacterial reduction rate, which is calculated by comparing the concentration of untreated and co-cultured bacterial suspensions with wound dressing specimens. In this study, quantitative antibacterial efficacy was evaluated according to the AATCC TM100 and ASTM E2149-20 separately. The results showed that among the 7 products tested by AATCC TM100, one product could not be evaluated because the material of the product could not absorb the bacterial suspension, and only 2 products had a bacteria reduction rate of > 99.99%. On the other hands, 8 out of 9 products tested based on ASTM E2149-20 reached a > 99.99% bacteria reduction rate. Based on the results, we speculated the step of immersing the test specimens of wound dressings into bacterial suspension thoroughly, along with adequate shaking could cause a better contact of the specimen with bacterial suspension, and foster antibacterial agents released from wound dressings under dynamic contact conditions.