Legakis N J, Protopappas N P, Leonardopoulos J G, Papavassiliou J T
Can J Microbiol. 1978 Mar;24(3):245-53. doi: 10.1139/m78-043.
Clinical isolates of Escherichia coli sensitive and resistant to penicillin were compared in lipid composition and 14C-labelled penicillin uptake, as possible factors in resistance. Except for a slight increase in the triglyceride fraction in sensitive strains there were no qualitative or quantitative differences in the classes of extractable lipids present. Gas-liquid chromatography of the phospholipid and triglyceride fatty acids of the polar and non-polar fatty acids of the bound lipids showed that the same kinds of fatty acids were present. There was an increase of myristate in the chloroform-methanol extractable lipids of highly resistant strains accompanied by a rather general decrease of other fatty acids. Gas-chromatographic analysis of the polar-bound lipids showed an increase of the beta-hydroxydecanoic acid in the resistant strains. By studying the uptake of 14C-labelled benzylpenicillin and the crypticity of the beta-lactamase, evidence has been produced that a decreased permeability of resistant strains to penicillin cooperates with beta-lactamase to induce a high level of resistance. The altered lipid metabolism may reflect the special architectural changes in the cell wall which cause decreased permeability.
对青霉素敏感和耐药的大肠杆菌临床分离株在脂质组成和14C标记青霉素摄取方面进行了比较，这些可能是耐药的因素。除了敏感菌株中甘油三酯部分略有增加外，可提取脂质类别在定性或定量上没有差异。对结合脂质的极性和非极性脂肪酸的磷脂和甘油三酯脂肪酸进行气液色谱分析表明，存在相同种类的脂肪酸。高耐药菌株的氯仿 - 甲醇可提取脂质中肉豆蔻酸增加，同时其他脂肪酸普遍减少。对极性结合脂质的气相色谱分析表明，耐药菌株中β - 羟基癸酸增加。通过研究14C标记苄青霉素的摄取和β - 内酰胺酶的隐蔽性，有证据表明耐药菌株对青霉素的通透性降低与β - 内酰胺酶协同作用，导致高水平耐药。脂质代谢的改变可能反映了细胞壁中导致通透性降低的特殊结构变化。
