鸡蛋清溶菌酶与β-内酰胺类抗生素联合应用对大肠埃希氏菌生物特性的影响

Effect of egg white lysozyme in combination with β-lactam antibiotics on biological characteristics of Escherichia coli O111:B4

考察在不同温度下鸡蛋清溶菌酶与 β-内酰胺类抗生素联合应用对大肠埃希氏菌的生长及内毒素释放的影响。在不同温度下培养的大肠埃希氏菌液中加入鸡蛋清溶菌酶和β-内酰胺类抗生素氨苄西林(ampicillin)或头孢噻肟 (cefotaxime) ,收集培养上清液 ,测定其内毒素浓度 ;将上清液加入到培养的巨噬细胞中 ,测定其对巨噬细胞炎性因子的诱生能力。结果 :在不同的培养温度下 ,氨苄西林或头孢噻肟 5 0 μg/ ml均可导致细菌溶解 ,并诱导 Escherichia coli O111:B4释放大量的内毒素到培养上清液中 ,这些培养上清液在体外培养的巨噬细胞上可诱导大量的肿瘤坏死因子 (TNFα)和白细胞介素 6 (IL- 6 )产生。而鸡蛋清溶菌酶与 β-内酰胺类抗生素联合使用能阻止细菌溶解 ,降低细菌内毒素的释放 ,并减少巨噬细胞 TNFα和 IL - 6的产生。结论 :鸡蛋清溶菌酶与β-内酰胺类抗生素联合使用能降低细菌内毒素的释放 。

Objective: To investigate the effect of egg white lysozyme in combination with β lactam antibiotics on the growth and endotoxin release of Escherichia coli O111:B4 cultured under different culture temperatures. Method: Escherichia coli O111:B4 which was cultured under different temperatures was treated with ampicillin or cefotaxime alone or in combination with egg white lysozyme. The culture supernatants were obtained and the concentrations of endotoxin in the supernatants were measured. TNFα and IL 6 productivity of the supernatants was assayed in macrophage culture. Result: Under different culture temperatures, the treatment of either ampicillun or cefotaxime alone induced lysis of Escherichia coli and caused a large amount of endotoxin releasing into the supernatant. The supernatant from ampicillin or cefotaxime treated bacterial culture showed high TNFα and IL 6 productivity in RAW 264.7 cells. Treatment of egg white lysozyme in combination with ampicillin or cefotaxime significantly inhibited bacteriolysis and reduced endotoxin release as well as TNFα and IL 6 production. Conclusion: The combination of egg white lysozyme with β lactam antibiotics may alleviate the endotoxemia by decreasing the release of endotoxin from bacteria.