大肠杆菌和铜绿假单胞菌内毒素的溶解性
Solubility of endotoxins from Escherichia coli and Pseudomonas aeruginosa.
作者信息
Eduard Wijnand, Westby Mette Haraldsen, Larsson Lennart
机构信息
National Institute of Occupational Health, Oslo, Norway.
出版信息
Am J Ind Med. 2004 Oct;46(4):375-7. doi: 10.1002/ajim.20089.
BACKGROUND
The Limulus amebocyte lysate (LAL) assay may underestimate endotoxins because only soluble endotoxins are determined. The solubility of endotoxins was, therefore, studied in two species of Gram-negative bacteria.
METHODS
Cultures were grown in serum broth, cells were harvested by centrifugation and washed in physiological saline. Bacterial suspensions were either filtered through PTFE filters and air dried at room temperature, dried in polypropylene tubes at room temperature in a desiccator, or freeze dried. Samples were extracted with aqueous Tween 20. The soluble and insoluble fractions were dried, methanolysed, and hydroxy-fatty acid methyl esters were determined by gas chromatography (GC) as markers of endotoxins.
RESULTS
The solubility of the endotoxins from Escherichia coli and Pseudomonas aeruginosa ranged from 9% to 83%. Species and drying conditions had substantial influence on the solubility.
CONCLUSIONS
Endotoxin exposure may be underestimated in environmental samples by the LAL test because a substantial fraction can be non-soluble and is not detected.
背景
鲎试剂检测法可能会低估内毒素含量，因为该方法仅测定可溶性内毒素。因此，研究了两种革兰氏阴性菌中内毒素的溶解性。
方法
在血清肉汤中培养细菌，通过离心收集细胞并用生理盐水洗涤。细菌悬液要么通过聚四氟乙烯滤器过滤并在室温下风干，要么在室温下于干燥器中的聚丙烯管中干燥，要么进行冷冻干燥。样品用吐温20水溶液提取。将可溶性和不溶性部分干燥、甲醇解，通过气相色谱法（GC）测定羟基脂肪酸甲酯作为内毒素的标志物。
结果
大肠杆菌和铜绿假单胞菌内毒素的溶解度在9%至83%之间。菌种和干燥条件对溶解度有显著影响。
结论
在环境样品中，鲎试剂检测法可能会低估内毒素暴露量，因为相当一部分内毒素可能不溶而未被检测到。
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