摘要目的 探讨使用抗生素封管技术(ALT)治疗导管相关性放射根瘤菌(R.radiobacter)感染的有效抗生素种类、浓度和作用时间.方法 参考相关文献,体外将放射根瘤菌人工感染至聚氨酯薄膜上,形成放射根瘤菌感染导管模型.将1、5、10 mg/ml 3种浓度的头孢曲松、头孢他啶、阿米卡星、环丙沙星分别与2株放射根瘤菌感染导管模型共同培养14d,在培养的第1、3、5、7、10、14天检测经过抗生素处理后聚氨酯薄膜上放射根瘤菌的剩余量.铜绿假单胞菌ATCC9027作为实验对照菌同时检测.结果 1 mg/ml的头孢曲松与放射根瘤菌感染导管模型共同培养至第3天无细菌生长,同浓度的环丙沙星和阿米卡星对放射根瘤菌感染导管模型的治疗效果均比头孢曲松差.10 mg/ml的头孢他啶分别与2株放射根瘤菌感染导管模型共同培养至第14天仍可检测到高浓度的细菌生长.结论 低浓度的头孢曲松能在3天内完全根除导管上的放射根瘤菌,环丙沙星和阿米卡星效果稍差,头孢他啶效果最差.

abstractsObjective To investigate appropriate antimicrobial agents,the optimal concentration and treatment duration for the antibiotic lock technique (ALT) to treat catheter-related infections caused by Rhizobium radiobacter (R.radiobacter).Methods With reference to literatures,the in-vitro model of catheterrelated R.radiobacter infections was established by inoculating the bacteria onto polyurethane films.Each two strains of R.radiobacter were co-cultured for 14 d with ceftriaxone,ceftazidime,amikacin and ciprofloxacin at three dose levels (1,5 and 10 mg/ml).On days 1,3,5,7,10 and 14,we examined the residual level of R.radiobacter on the antibiotic-treated polyurethane films.Pseudomonas aeruginosa ATCC9027 was used as the control bacteria and studied in the same manner.Results The biofilms were completely sterile after exposure to 1 mg/ml ceftriaxone for 3 days.The therapeutic effects of ciprofloxacin and amikacin at the same concentrations on R.radiobacter catheter infection were worse compared with ceftriaxone.High-concentration growth of R.radiobacter remained detectable even till the day 14 when 10 mg/ml ceftazidime was used for coculture with 2 bacterial strains.Conclusion Ceftriaxone can eradicate R.radiobacter biofilms within 3 days.Such bactericidal effect may be worse with ciprofloxacin and amikacin,and worst with ceftazidime.