抗菌药物诱导大肠杆菌内毒素释放的研究

Antibiotic induced Release of Endotoxin from Escherichia Coliin Vitro

目的：探讨不同类型的抗菌药物释放细菌内毒素潜能和速率的不同。方法：选择５ 种不同类型抗菌药物单独或联合作用于大肠杆菌，比较４ ｈ 期间游离内毒素，同时作菌落计数和细菌形态学检查。结果：亚胺培南西司他丁杀菌作用和释放内毒素最快，但释放内毒素量较少；头孢他啶释放内毒素较快，量较多；环丙沙星释放缓慢，量中等；阿米卡星释放缓慢，量最小；头孢曲松致细菌丝状体形成，杀菌并释放内毒素最慢但量最大；阿米卡星和头孢曲松联合用药有协同抗菌作用，且明显减少头孢曲松释放内毒素的量，与单独使用阿米卡星释放内毒素的量近似。结论：不同类型抗菌药物诱导细菌内毒素释放的量和速率不同。

Objective : To study the differences in the rate and extentof endotoxin release by different classes of an timicrobial agents . Methods : Free endotoxin release in time from cultures of Escherichia coli by differenttypes and com binations of antimicrobial agents was studied in vitro for 4 h . Viable counts were obtained simultanously . The morphologyofthe bacteria was examined during antibiotic exposure . Results : The most rapid fall in viable counts and release L P Swere seen aftertreatment with imipenem ,but lessincrease in the level offree endotoxin . Ceftizadime induced release ofendotoxin atfaster rate and in greater amounts. Ciprofloxacin caused a late and modest endotoxin liberating . Amikacininduced a late and the least amounts of endotoxin release . Treatment with ceftriaxone killed bacteria and induced a rela tively late but the greatest release of endotoxin ,which was due to conversion of bacteriato long filamentous forms . Com bination of amikacin and ceftriaxone has obvious synergism ,and resulted in a singificant decrease in endotoxin liberationin comparsion with that ceftriaxone monotherapy . Conclusion : The amount and rate of L P Srelease from bacteria was de pendent upon antibiotic class .