使用濃度梯度產生器微流道晶片結合表面增強拉曼散射進行組合抗生素敏感性試驗

Abstract

抗生素抗藥性已成為全球公共衛生的重大挑戰，造成許多細菌感染難以治療，且與高死亡率相關。為了提升治療效果並延緩抗藥性的發展，組合性抗生素治療被視為一項重要策略，尤其適用於多重耐藥性菌株的感染情形。然而目前進行細菌鑑定和抗生素敏感性試驗 (antimicrobial susceptibility testing, AST) 動用許多勞力、所花費的時間較長，而且也只能關注在單一種抗生素上。為了解決上述的問題，我們開發了一種整合微流道和表面增強拉曼散射 (surface-enhanced Raman scattering, SERS) 的系統，簡化傳統AST繁雜的流程並實現原位檢測。此外，微流道能夠產生兩倍的抗生素濃度梯度，並且能夠在微流井 (microwell) 裡混合兩種抗生素，得到36種不同的抗生素組合。此外微流井也可以捕捉細菌，與抗生素混合進行培養後，利用SERS進行量測，根據SERS的訊號便可測得微量抑制濃度指數 (fractional inhibitory concentration index, FICI)。為了驗證本研究的可行性，我們在此裝置上使用卡那黴素 (kanamycin) 非抗藥性和抗藥性的大腸桿菌 (Escherichia coli) 進行測試。整體而言，這個系統可以執行組合抗生素敏感性試驗，並具有操作簡單、樣本使用量少和分析時間更短的優勢。

Antimicrobial resistance poses a significant global public health challenge, making many bacterial infections difficult to treat and contributing to high mortality rates. Combinatory antimicrobial therapy has been recognized as a crucial strategy to enhance treatment efficacy and slow the development of resistance, particularly for infections caused by multidrug-resistant strains. However, current bacterial identification and antimicrobial susceptibility testing (AST) procedures are labor-intensive, time-consuming, and can only focus on single antibiotic treatment. To address the above issues, we report a system integrating microfluidics and surface-enhanced Raman scattering (SERS) to simplify the conventional AST workflow and perform in situ detection. Besides, the microfluidics can generate two-fold antibiotic concentration gradients and enable mixing two antibiotics within microwells, resulting in 36 individual antibiotic combinations. Additionally, the microwells can capture bacteria, which are incubated with antibiotics and analyzed using SERS. Fractional inhibitory concentration index (FICI) values can then be calculated based on SERS signals. To demonstrate the feasibility of this thesis, kanamycin-susceptible and -resistant Escherichia coli strains were tested on our device. This system can perform combinatory AST with a simple operation, fewer sample requirements, and shorter analysis time.