Evaluation of antibacterial properties of novel phthalocyanines against Escherichia coli--comparison of analytical methods.
Evaluation of antibacterial properties of novel phthalocyanines against Escherichia coli--comparison of analytical methods.
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DOI：
10.1016/j.jphotobiol.2014.04.014
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发表时间：
2014-09
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影响因子：
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通讯作者：
P. Mikula;L. Kalhotka;D. Jančula;Štěpán Zezulka;R. Kořínková;J. Černý;B. Maršálek;P. Toman
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文献类型：
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作者：
P. Mikula;L. Kalhotka;D. Jančula;Štěpán Zezulka;R. Kořínková;J. Černý;B. Maršálek;P. Toman
我们分析了几种新型酞菁对大肠杆菌的抗菌作用，并与常规培养相比，评估了流式细胞术检测酞菁抗菌作用的适用性。在冷白光下暴露 3 小时后，8 种阳离子酞菁在 2.00 mg L−1 的浓度下表现出非常高的抗菌活性，其中 4 种在 0.20 mg L−1 的浓度下甚至表现出很高的抗菌活性。中性和阴离子化合物的抗菌活性相当低，甚至可以忽略不计。当细菌在没有光照的情况下暴露时，没有检测到抗菌作用。研究发现，与细菌细胞的结合亲和力是影响酞菁抗菌活性的一个重要参数，可以通过外围取代基的总电荷以及其中存在的合适官能团来改变该活性。在用较高浓度的某些阳离子酞菁（细菌膜最强的结合剂）处理的悬浮液中观察到的细胞团聚影响了总细胞计数的细胞计数测量，因此在分析之前没有对样品进行适当的预处理，该参数在评估酞菁抗菌活性时似乎并不完全有效。细胞膜完整性的细胞计数测量似乎是一个合适的参数，甚至比培养更敏感。
We analyzed antibacterial effects of several novel phthalocyanines againstEscherichia coliand evaluated the suitability of flow cytometry for the detection of antibacterial effects of phthalocyanines in comparison with routinely used cultivation. After 3 h of exposure under cool white light eight cationic phthalocyanines showed very high antibacterial activity in the concentration of 2.00 mg L−1and four of them were even efficient in the concentration of 0.20 mg L−1. Antibacterial activity of neutral and anionic compounds was considerably lower or even negligible. No antibacterial effect was detected when bacteria were exposed without illumination. Binding affinity to bacterial cells was found to represent an important parameter influencing phthalocyanine antibacterial activity that can be modified by total charge of peripheral substituents and by the presence of suitable functional groups inside them. Agglomeration of cells observed in suspensions treated with a higher concentration of certain cationic phthalocyanines (the strongest binders to bacterial membrane) affected cytometric measurements of total cell counts, thus without appropriate pretreatment of the sample before analysis this parameter seems not to be fully valid in the evaluation of phthalocyanine antibacterial activity. Cytometric measurement of cell membrane integrity appears to be a suitable and even more sensitive parameter than cultivation.