Abstract:

Objective Donor-derived infection （DDI） caused by carbapenem-resistant Gram-negative bacilli （CRGNB） leads to severe clinical consequences. This study aimed to investigate the antibacterial effect of colistimethate sodium （CMS） on four CRGNB strains when added to organ preservation solution after pretreatment on four CRGNB strains， and to provide a theoretical basis for CMS application in in vitro decontamination of preservation solution . Methods The clinical decontamination process was simulated. Bacterial suspensions of four CRGNB strains were added to organ preservation solution to evaluate whether CMS and amikacin （AK） could eliminate the bacteria. Furthermore， the elimination ability of CMS with different concentrations， CMS treated with different water bath temperatures and different heating durations against CRGNB were explored. Results At low temperature （4℃）， CMS at standard concentration and AK showed poor antibacterial efficacy. Compared with the AK group， the bacterial load of CRGNB contamination was significantly decreased in the CMS group with 4-fold concentration CMS group 〔（86.14±20.37）% vs（29.77±5.67）%，P ＝ 0.002〕. In addition， after pretreatment such as water bath heatingand prolonged time， the bacterial load was significantly reduced in the 60℃ +15 min group and 60℃ +30 min group 〔（0.78±0.159） CFU/g vs（0.56±0.458） CFU/g，P＝ 0.002〕， after pretreatment, such as water bath heating and prolonged time，with no statistical difference between the two groups . Conclusion CMS has poor antibacterial activity against CRGNB at low temperature， and it is difficult to achieve clinically satisfactory antibacterial efficacy even with a greatly increased concentration. Pretreatment can endow CMS with extremely strong decontamination ability， which can effectively prevent CRGNB contamination of grafts even at low temperatures. 

Key words:

 , Colistimethate sodium ,  , Carbapenem-resistant Gram-negative bacilli ,  , Organ preservation ,  , In vitro decontamination

摘要：

目的 耐碳青霉烯类革兰氏阴性菌（carbapenem-resistant gram-negative bacilli，CRGNB）导致的供者来源的感染（donor-derived infection，DDI）后果严重。拟探究通过预处理多黏菌素 E 甲磺酸钠（colistimethatesodium，CMS）添加在器官保存液中对 4 种 CRGNB 的抑菌效果，为 CMS 用于保存液体外去污提供理论依据。方法 本研究模拟了临床去污流程，在器官保存液中分别添加 4 种 CRGNB 的菌悬液，以研究阿米卡星（amikacin，AK）和 CMS 能否其清除细菌，并进一步探究不同浓度的 CMS、不同水浴温度及不同加热时间处理的 CMS 对 CRGNB 的清除能力。结果 低温条件下（4℃），标准浓度的 CMS 组和 AK 组的抑菌效果并不佳。但与 AK 组相比，CRGNB 污染在 4 倍浓度的 CMS 组〔（86.14±20.37）% 比（29.77±5.67）%，P ＝ 0.002〕中的细菌负荷下降，两者有统计学差异。此外，通过水浴、时间延长等预处理后，60℃ +15 min 组和 60℃ +30 min 组〔（0.78±0.159） CFU/g 比（0.56±0.458） CFU/g，P ＝ 0.002〕细菌负荷显著降低，两组无统计学差异。结论 CMS 在低温下对 CRGNB 的抑菌能力较差，即使大幅提高浓度也很难达到临床上满意的抑菌效果，预 处理后则可发挥极强去污能力，即使在低温条件下也能有效防止移植物的 CRGNB 污染。

关键词: 多黏菌素 E 甲磺酸钠 , 耐碳青霉烯类革兰氏阴性菌 , 器官保存 , 体外去污