Harding G B, Pass T, Wright R
University of Louisville, USA.
Artif Organs. 1992 Oct;16(5):448-56. doi: 10.1111/j.1525-1594.1992.tb00322.x.
Reports of increasing endotoxic reactions in dialysis centers using high-flux dialyzers and high contamination in liquid bicarbonate concentrates have resulted in concern for the microbial contamination of dialysate. The influence of salt-supplemented media on the recovery of bacterial contaminants from the fluids used in hemodialysis has been examined. This study found a negative influence of a 2% NaCl supplementation of growth media for both purified water and dialysate. Salt-supplemented pour plate cultures of bicarbonate concentrate samples were not statistically different from nonsupplemented cultures (p = 0.2). The influence of the bicarbonate salt on recovery in the pour plates was not addressed. The different media recommended for monitoring microbial contamination of dialysis fluids were compared. As previously reported, both water and dialysate collected from a relatively large geographic area showed higher recoveries on Reasoner's R2A agar than on media recommended by the Association for Advancement of Medical Instrumentation (AAMI) standards (p < 0.0001). Standard methods agar (SMA) and trypticase soy agar (TSA) produced the next highest recovery for water and dialysate, respectively. The higher recoveries generally observed on R2A or SMA suggest that to provide better patient safety these media should be selected for monitoring bacterial contamination of water, and R2A, SMA, or TSA for dialysate. The variability in the species identified across the three fluids and variability in counts observed in the different fluids suggest that significant dialysate contamination may occur from sources other than the water and bicarbonate concentrates.
有报告称，在使用高通量透析器的透析中心内，内毒素反应不断增加，且液体碳酸氢盐浓缩物存在高度污染，这引发了人们对透析液微生物污染的担忧。研究人员已考察了添加盐分的培养基对从血液透析所用液体中回收细菌污染物的影响。本研究发现，在用于纯净水和透析液的生长培养基中添加2%氯化钠会产生负面影响。碳酸氢盐浓缩物样本添加盐分的倾注平板培养物与未添加盐分的培养物在统计学上无显著差异（p = 0.2）。研究未探讨碳酸氢盐对倾注平板回收情况的影响。对推荐用于监测透析液微生物污染的不同培养基进行了比较。如先前报道，从相对较大地理区域采集的水和透析液在里森纳R2A琼脂上的回收率均高于美国医疗器械促进协会（AAMI）标准推荐的培养基（p < 0.0001）。标准方法琼脂（SMA）和胰蛋白酶大豆琼脂（TSA）分别对水和透析液产生了次高的回收率。通常在R2A或SMA上观察到的较高回收率表明，为提供更好的患者安全性，应选择这些培养基来监测水的细菌污染，选择R2A、SMA或TSA来监测透析液。三种液体中鉴定出的菌种存在变异性，且不同液体中观察到的菌落计数也存在变异性，这表明除了水和碳酸氢盐浓缩物之外，透析液可能还存在其他来源的严重污染。
