Drulis-Kawa Zuzanna, Dorotkiewicz-Jach Agata, Gubernator Jerzy, Gula Grzegorz, Bocer Tomasz, Doroszkiewicz Wlodzimierz
Institute of Genetics and Microbiology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.
Int J Pharm. 2009 Feb 9;367(1-2):211-9. doi: 10.1016/j.ijpharm.2008.09.043. Epub 2008 Oct 5.
The interactions between cationic liposomal formulations (PC:Chol:DOTAP 3:4:3) and 23 Pseudomonas aeruginosa strains were tested. The study was undertaken because different antimicrobial results had been obtained by the authors for Pseudomonas aeruginosa strains and liposomal antibiotics (Drulis-Kawa, Z., Gubernator, J., Dorotkiewicz-Jach, A., Doroszkiewicz, W., Kozubek, A., 2006. The comparison of in vitro antimicrobial activity of liposomes containing meropenem and gentamicin. Cell. Mol. Biol. Lett., 11, 360-375; Drulis-Kawa, Z., Gubernator, J., Dorotkiewicz-Jach, A., Doroszkiewicz W., Kozubek, A., 2006. In vitro antimicrobial activity of liposomal meropenem against Pseudomonas aeruginosa strains. Int. J. Pharm., 315, 59-66). The experiments evaluate the roles of the bacterial outer-membrane structure, especially outer-membrane proteins and LPS, and envelope properties (hydrophobicity and electrostatic potential) in the interactions/fusion process between cells and lipid vesicles. The interactions were examined by fluorescent microscopy using PE-rhodamine-labelled liposomes. Some of the strains exhibited red-light emission (fusion with vesicles or vesicles surrounding the cell) and some showed negative reaction (no red-light emission). The main aim of the study was to determine what kinds of bacterial structure or envelope properties have a major influence on the fusion process. Negatively charged cells and hydrophobic properties promote interaction with cationic lipid vesicles, but no specific correlation was noted for the tested strains. A similar situation concerned LPS structure, where parent strains and their mutants possessing identical ladder-like band patterns in SDS-PAGE analysis exhibited totally different results with fluorescent microscopy. Outer-membrane protein analysis showed that an 18-kDA protein occurred in the isolates showing fusion with rhodamine-labelled vesicles and, conversely, strains lacking the 18-kDA protein exhibited no positive reaction (red emission). This suggests that even one protein may be responsible for favouring stronger interactions between Pseudomonas aeruginosa cells and cationic liposomal formulations (PC:Chol:DOTAP 3:4:3).
测试了阳离子脂质体制剂（PC:Chol:DOTAP 3:4:3）与23株铜绿假单胞菌之间的相互作用。开展该研究是因为作者针对铜绿假单胞菌菌株和脂质体抗生素获得了不同的抗菌结果（德鲁利斯-卡瓦，Z.，古贝纳托，J.，多罗特凯维茨-亚赫，A.，多罗什凯维茨，W.，科祖贝克，A.，2006年。含美罗培南和庆大霉素脂质体的体外抗菌活性比较。细胞与分子生物学快报，11，360 - 375；德鲁利斯-卡瓦，Z.，古贝纳托，J.，多罗特凯维茨-亚赫，A.，多罗什凯维茨，W.，科祖贝克，A.，2006年。脂质体美罗培南对铜绿假单胞菌菌株的体外抗菌活性。国际药学杂志，315，59 - 66）。实验评估了细菌外膜结构，尤其是外膜蛋白和脂多糖，以及包膜性质（疏水性和静电势）在细胞与脂质囊泡相互作用/融合过程中的作用。使用PE - 罗丹明标记的脂质体通过荧光显微镜检查相互作用。一些菌株呈现红光发射（与囊泡融合或囊泡围绕细胞），一些则呈阴性反应（无红光发射）。该研究的主要目的是确定何种细菌结构或包膜性质对融合过程有重大影响。带负电荷的细胞和疏水性促进与阳离子脂质囊泡的相互作用，但在所测试的菌株中未发现特定相关性。脂多糖结构也有类似情况，在SDS - PAGE分析中具有相同梯状条带模式的亲本菌株及其突变体在荧光显微镜下呈现出完全不同的结果。外膜蛋白分析表明，在与罗丹明标记的囊泡融合的分离株中出现一种18 kDa的蛋白，相反，缺乏该18 kDa蛋白的菌株未呈现阳性反应（红色发射）。这表明即使一种蛋白也可能是促进铜绿假单胞菌细胞与阳离子脂质体制剂（PC:Chol:DOTAP 3:4:3）之间更强相互作用的原因。
