碩士 / 國立臺灣大學 / 微生物與生化學研究所 / 92 / Photodynamic antimicrobial chemotherapy (PACT), derived from photodynamic therapy (PDT), utilized photosensitizer (PS) and visible or ultraviolet light in order to give a phototoxic response, normally via oxidative damage to microorganisms. Because neither of the two major factors (lights and PSs) of the PACT is inherently bactericidal, it could be a useful and simple way to treat and control antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). Although lethal photosensitization of a wide range of microorganisms has been reported, the lack of specificity and inefficiency of light activation limit its application. The goal of this study is to establish a PACT system to treat flowing S. aureus and MRSA by immobilized PS that could be irradiated in vitro. Merocyanine 540 (MC540), a fluorescent dye that binds to the outer surface of the plasma membrane, had been widely used in blood sterilization and in inactivation against both planktonic culture and biofilm of S. aureus. In order to distinguish blood cells and bacteria, MC540 was immobilized by alginate beads to form porous medium which only allowed bacteria passed through. The characteristics of beads and the ability of MC540-alginate beads irradiated by green light emitting diode (LED) to inactivation flowing S. aureus strains in the circular reactor were reported. In addition, a blood sample containing S. aureus was also treated using this approach. The diameter of beads was between 1.81 and 3.10 mm. After 108 CFU/mL bacteria incubated with 10 alginate beads, there was around 1/10 bacteria bound to beads. In small scale treatment, when incident dose was up to 72 J/cm2, no viable cell of S. aureus was could be detected. In circular reactor, the best result of PACT treatment could suppress around 5 log CFU/mL. Although PACT showed minor inactivation in blood, this research showed a potential strategy of inactivation bacteria in blood and proposed a novel strategy by immobilizing photosensitizer to enhance PACT. This system was efficient to damage both wild type and antibiotic-resistant S. aureus.
| Identifer | oai:union.ndltd.org:TW/092NTU05381045 |
| Date | January 2004 |
| Creators | Chia-Fen Lee, 李佳芬 |
| Contributors | Ching-Tsan Huang, 黃慶璨 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 82 |
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