Lee Mi Young, Ko Kwan Soo, Song Jae-Hoon, Peck Kyong Ran
Asian-Pacific Research Foundation for Infectious Diseases, Seoul 135-710, Korea.
J Antimicrob Chemother. 2007 Oct;60(4):782-7. doi: 10.1093/jac/dkm295. Epub 2007 Aug 5.
To determine the adequate antibiotic treatment, the concentration of antibiotics and the duration of treatment with the antibiotic lock technique (ALT) for treatment of central venous catheter-related infections caused by Klebsiella pneumoniae and Pseudomonas aeruginosa.
To investigate the in vitro effectiveness of four candidate antibiotics, amikacin, ceftazidime, cefepime and ciprofloxacin, two isolates of both K. pneumoniae and P. aeruginosa forming biofilms were selected. The polyurethane (PU) films were incubated for 5 days to allow for bacterial colonization or biofilm production. After 5 days, the biofilm-formed PU films were exposed to each of the antibiotics (1, 5 and 10 mg/mL) for 1, 3, 5, 7, 10 and 14 days. The presence of the remaining bacteria in the biofilm was evaluated by the determination of viable cell counts.
All of the antibiotic treatments effectively removed P. aeruginosa biofilm within 3-5 days. Among the four antimicrobial agents tested in this study, ciprofloxacin showed superior bactericidal activity. The biofilms of both species were eliminated by 5 mg/mL ciprofloxacin within 3 days. In all cases, P. aeruginosa strains were removed more rapidly than K. pneumoniae strains. All antibiotics eradicated the susceptible K. pneumoniae strain, K144, within 5 days. One strain of K. pneumoniae, K139, which was resistant to all tested antibiotics, was not eradicated by amikacin (1, 5 and 10 mg/mL) or 1 mg/mL ceftazidime.
These results show that ciprofloxacin, cefepime, ceftazidime and amikacin might be used as an effective ALT for treatment of catheter-related infections caused by antibiotic-susceptible K. pneumoniae and P. aeruginosa. This study suggests that the duration of treatment against catheter-related infection by Gram-negative bacilli can be reduced to 3-5 days when using antibiotics to which the organisms are susceptible in vitro, even at a concentration of 1 mg/mL.
确定使用抗生素封管技术（ALT）治疗肺炎克雷伯菌和铜绿假单胞菌引起的中心静脉导管相关感染时的适当抗生素治疗方案、抗生素浓度及治疗持续时间。
选取肺炎克雷伯菌和铜绿假单胞菌的两个形成生物膜的分离株，研究阿米卡星、头孢他啶、头孢吡肟和环丙沙星这四种候选抗生素的体外有效性。将聚氨酯（PU）膜孵育5天以促进细菌定植或生物膜形成。5天后，将形成生物膜的PU膜分别暴露于每种抗生素（1、5和10mg/mL）中1、3、5、7、10和1天。通过测定活菌数评估生物膜中剩余细菌的存在情况。
所有抗生素治疗在3 - 5天内有效清除了铜绿假单胞菌生物膜。在本研究测试的四种抗菌药物中，环丙沙星显示出较强的杀菌活性。两种菌的生物膜在3天内被5mg/mL环丙沙星清除。在所有情况下，铜绿假单胞菌菌株比肺炎克雷伯菌菌株清除得更快。所有抗生素在5天内根除了敏感的肺炎克雷伯菌菌株K144。一株对所有测试抗生素耐药的肺炎克雷伯菌K139未被阿米卡星（1、5和10mg/mL）或1mg/mL头孢他啶根除。
这些结果表明，环丙沙星、头孢吡肟、头孢他啶和阿米卡星可能用作治疗由抗生素敏感的肺炎克雷伯菌和铜绿假单胞菌引起的导管相关感染的有效ALT。本研究表明，当使用体外对革兰氏阴性杆菌敏感的抗生素时，即使浓度为1mg/mL，针对导管相关感染的治疗持续时间也可缩短至3 - 5天。
