透析用水细菌及内毒素含量在热消毒和化学消毒全过程中的动态规律特征研究

 目的 观察透析用水中细菌存活及内毒素含量在两种消毒过程中的动态变化情况。利用数据模型拟合消毒过程中微生物指标变化规律,为日常感染监控及管路消毒维护管理决策提供基础数据支撑。方法 分析消毒程序模式的时间和温度参数,采集热消毒和化学消毒前后输水管路回水口或混合室入口处的透析用水,检测内毒素,同时平行水样经薄膜过滤法富集,在20℃下TGEA培养7 d,计数细菌菌落。通过Origin软件的数据拟合,描述细菌和内毒素含量与温度、时间变化的特征关系。结果 细菌存活率随着消毒程序时间的延长而减少,在50~160 min时,细菌存活情况变化幅度大,热消毒细菌含量减少的变化比化学消毒平缓。热消毒中内毒素含量随着温度不断上升而增加,随着冷却温度下降而减少。在70、80℃时内毒素含量最高,首机处内毒素含量整体水平高于中间机和尾机。化学消毒内毒素含量集中升高在消毒剂浸泡冲洗时间段,之后下降而趋于平稳。热消毒和化学消毒完内毒素持续情况均为先下降到较低值,在热消毒后15 h、化学消毒后12 h,内毒素略呈现上升趋势,出现小峰值。结论 温度和时间是影响透析用水微生物指标决定性的参数,可利用微生物数据建立拟合数据描述两种消毒全过程透析用水中细菌失活和内毒素变化规律的异同。同时模型工具补充了透析用水监测方法,有助于更好地实现透析用水消毒控制及效果。

Dynamic characteristics of bacteria and endotoxin content in dialysis water during the process of thermal disinfection and chemical disinfection

Objective To observe the dynamic changes of bacterial survival and endotoxin content in dialysis water during two disinfection processes. The data model was used to fit the changing regulation of microbial indexes during the process of disinfection, and provide basic data support for daily infection control as well as management decisions for pipeline disinfection maintenance. Methods The time and temperature parameters of disinfection procedure mode were analyzed, dialysis water at backwater outlet of water supply pipeline or the entrance of mixing chamber before and after thermal disinfection and chemical disinfection were collected to detect endotoxin, parallel specimens of dialysis water were enriched by membrane filtration method and cultured with TGEA at 20℃ for 7 days, bacterial colonies were counted. Data fitting of Origin software was used to describe the characteristic relationship between the content of bacteria as well as endotoxin and temperature as well as time. Results The survival rate of bacteria decreased with the extension of disinfection procedure time, bacterial survival changed greatly at 50-160 minutes, the decrease of bacterial content in thermal disinfection was more gentle than that in chemical disinfection. The content of endotoxin in thermal disinfection increased with the enhancing of temperature and decreased with the dropping of cooling temperature. Endotoxin content was the highest at 70℃ and 80℃, endotoxin content in the first machine was higher than that in the middle machine and the tail machine. The concentration of endotoxin in chemical disinfection increased during the period of immersion and washing of disinfectant, and then decreased and tended to be stable. After thermal disinfection and chemical disinfection, endotoxin continued to decrease to a lower value first, endotoxin increased slightly at 15 hour and 12 hour after thermal disinfection, with a small peak. Conclusion Temperature and time are the decisive parameters affecting the microbial indexes of dialysis water. Fitting data based on microbial data can be established to describe the differences and similarities of bacterial inactivation and endotoxin changes in dialysis water during two disinfection processes. At the same time, the model tool supplemented the monitoring method of dialysis water, which is helpful to achieve the disinfection control and effect of dialysis water better.