Arvanitidou M, Spaia S, Katsinas C, Pangidis P, Constantinidis T, Katsouyannopoulos V, Vayonas G
Laboratory of Hygiene, Medical School, University of Thessaloniki, Greece.
Nephrol Dial Transplant. 1998 Apr;13(4):949-54. doi: 10.1093/ndt/13.4.949.
Bacterial contamination of treated water and dialysate comprises an important problem for patients undergoing haemodialysis. Both the progressive reduction of the thickness of cellulose membranes and the expanding use of high-flux membranes probably enhance the risk of pyrogenic reactions, therefore increasing the need for atoxic water and non-pyrogenic dialysis fluid.
Samples of tap water, treated water, and effluent dialysate in all 85 haemodialysis centres in Greece were examined for total heterotrophic bacteria counts employing the pour plate method, total and faecal coliforms, faecal streptococci and pseudomonas spp. using the membrane filter technique, and sulphite-reducing clostridia applying the most probable number method. Overall 255 paired samples were tested from January to March 1997.
For total heterotrophic bacteria, the overall compliance of treated water and dialysate to the American Association of Medical Instrumentation standards (<200 c.f.u./ml for water and <2000 c.f.u./ml for dialysate) was 92.6 and 63.7% respectively, whereas the compliance of tap water samples to our national standards (total heterotrophic bacteria < 10 c.f.u./ml and absence of the other indicator bacteria) was 80.7%. The most commonly isolated bacteria were pseudomonas spp., found in 22.2% of treated water and 59.5% of dialysate samples, whereas the respective frequencies were 12.3 and 36.2% for total coliforms, 8.6 and 30.0% for faecal coliforms, 14.8 and 28.7% for faecal streptococci, and sulphite-reducing clostridia were isolated in 5.8% of dialysate samples only. Haemodialysis centres equipped with storage tanks for treated water experienced lower levels of total heterotrophic bacteria, but higher counts of total and faecal coliforms, faecal streptococci, and pseudomonas spp., although the difference was statistically significant only for faecal streptococci counts, (P<0.05). Sixty-seven haemodialysis centres were equipped with bacterial filters, but mean values of all the examined microorganisms were not statistically different from those of the other centres. Faecal streptococci counts in treated water samples were positively correlated with ageing of both haemodialysis centres (P<0.005) and purification system (P<0.05), whereas pseudomonas counts were significantly correlated with ageing of the purification system (P<0.05).
经处理的水和透析液的细菌污染是血液透析患者面临的一个重要问题。纤维素膜厚度的逐渐减小以及高通量膜的广泛使用可能会增加热原反应的风险，因此对无毒水和无热原透析液的需求也日益增加。
采用倾注平板法检测希腊所有85个血液透析中心的自来水、经处理的水和透析废液中的总异养菌数，采用膜过滤技术检测总大肠菌群、粪大肠菌群、粪链球菌和假单胞菌属，采用最大可能数法检测亚硫酸盐还原梭菌。1997年1月至3月共检测了255对样本。
对于总异养菌，经处理的水和透析液总体符合美国医学仪器协会标准（水<200 c.f.u./ml，透析液<2000 c.f.u./ml）的比例分别为92.6%和63.7%，而自来水样本符合我国标准（总异养菌<10 c.f.u./ml且无其他指示菌）的比例为80.7%。最常分离出的细菌是假单胞菌属，在22.2%的经处理的水样本和59.5%的透析液样本中被发现，而总大肠菌群的相应比例分别为12.3%和36.2%，粪大肠菌群为8.6%和30.0%，粪链球菌为14.8%和28.7%，亚硫酸盐还原梭菌仅在5.8%的透析液样本中被分离出。配备经处理水储存罐的血液透析中心总异养菌水平较低，但总大肠菌群、粪大肠菌群、粪链球菌和假单胞菌属的数量较高，不过差异仅在粪链球菌计数方面具有统计学意义（P<0.05）。67个血液透析中心配备了细菌过滤器，但所有检测微生物的平均值与其他中心相比无统计学差异。经处理的水样本中的粪链球菌计数与血液透析中心的老化程度（P<0.005）和净化系统的老化程度（P<0.05）均呈正相关，而假单胞菌计数与净化系统的老化程度显著相关（P<0.05）。
