赤蘚紅對細菌及酵母菌之光動力效應探討

Investigation of Erythrosine-mediated Photodynamic Inactivation Against Bacteria and Yeast

曾鈺涵(Yu-Hang Tseng)

指導教授 ： 蔡翠敏

臺北醫學大學/口腔醫學院/生醫材料暨工程研究所/碩士(2010年)

https://doi.org/10.6831/TMU.2010.00210

摘要

光動力療法乃是結合光感物質及適當波長之光源，經由電子或能量轉移產生能進行無特異性目標攻擊之活性氧類 (reactive oxygen species)，以破壞腫瘤及病原體。為尋求解決日漸嚴重的抗藥性問題，使得光動力殺菌逐漸成為替代性治療微生物的方式。赤蘚紅 (Erythrosine)，為臨床牙科使用的牙菌斑顯示劑，具有低毒性、易結合至菌體之特性，並且已有文獻指出赤蘚紅對於革蘭氏陽性菌之(Streptococcus mutans) 具有良好之光動力殺菌能力。在本實驗中，藉由赤蘚紅對轉糖鏈球菌具有光動力殺菌效果，探討作用於其他種革蘭氏陽性菌、革蘭氏陰性菌及酵母菌類之光動力殺菌的能力。實驗中針對革蘭氏陽性菌(金黃葡萄球菌、轉糖鏈球菌)、革蘭氏陰性菌(綠膿桿菌、大腸桿菌)及酵母菌(白色念珠菌)代表性菌株進行懸浮菌體及生物膜之光動力殺菌探討。
實驗結果顯示當赤蘚紅濃度為 20 mM 以下，不照光的情況，對於革蘭氏陽性菌、革蘭氏陰性菌及酵母菌的菌數影響不大，顯示赤蘚紅本身對菌體並不會造成傷害。首先探討懸浮菌體部分，在照光強度為50 J/cm2 下，赤蘚紅的濃度為 0.05 mM 時，皆可將革蘭氏陽性菌全部撲殺;而對於白色念珠菌則需將濃度提高至4 mM，才可同樣可達到消滅全部菌體；革蘭氏陰性菌之效果則不顯著，但在0.1%醋酸環境下，可促進光動力殺菌效果。生物膜部份，白色念珠菌生物膜對光動力耐受性較強，即使作用 20 mM 赤蘚紅、光照劑量提高至100 J/cm2，仍無明顯殺菌效果；金黃葡萄球菌及轉糖鏈球菌生物膜對光動力較具感受性，光照 50 J/cm2 下，分別作用0.05 mM 赤蘚紅皆可達到全殺狀態。此研究顯示赤蘚紅對革蘭氏陽性菌懸浮菌體及生物膜有良好之光動力殺菌效果，在未來的應用上極具潛力。

關鍵字

光動力療法 ； 赤蘚紅 ； 革蘭氏陽性菌 ； 革蘭氏陰性菌 ； 酵母菌

並列摘要

Photodynamic therapy (PDT) combines the photosensitizers (PSs) and visible light to produce a phototoxic response that results in oxidative damages to a variety of targets including nucleic acids, proteins, and lipids. In recent years, the growing resistance to antibiotics among pathogenic bacteria rendered antimicrobial photodynamic inactivation (PDI) as an alternative anti-infection treatment modality. Erythrosine, a clinical plaque disclosing agent, has been reported to have PDI efficacy against Streptococcus mutans. In this study, we investigated the effect of PDI on the viability of gram-positive (Staphylococcus aereus and Streptococcus mutans), gram-negative (Pseudomonas aeruginosa and Escherichia coli) and yeast (Candida albicans) planktonic cells and biofilm using erythrosine as the photosensitizer.
The results in this study show that 20 mM of erythrosine has no dark toxicity to the gram-positive, gram-negative and yeast. For planktonic cells treated with PDI, using 0.05 mM of erythrosine and irradiation light dose of 50 J/cm2, no viable cells of Gram-positive were detected. When concentration of erythrosine was raised to 4 mM, no viable cells of Candida albicans were detected. However, the gram-negative bacteria not effective to the treatment. However, 0.1% acetic acid evironment could enhance the PDI against gram-negative bacteria. For biofilm treated with PDI, Candida albicans biofilm shows high tolerance to PDI treatment and was no effective to the treatment, even at 20 mM of erythrosine and 100 J/cm2. Gram-positive (Staphylococcus aereus and Streptococcus mutans) biofilm were more sensitive to PDI treatment, and increase the dose of erythrosine to 0.05 mM and the light dose to 50 J/cm2 could result in complete eradication of the bacteria. This study showed that erythrosine was a potential photosensitizer for PDI against gram-positive bacteria and yeast.

並列關鍵字

Photodynamic inactivation ； Erythrosine ； Gram-positive ； Gram-negative ； Yeast

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