Endotoxin concentration in treated water of all hemodialysis units in Greece and inquisition of influencing factors

Mains and purified water samples from all hemodialysis centers in Greece we re surveyed to assess hemodialysis water quality and the potential conseque nces on the dialysis population of any microbial and endotoxin contaminatio n. Total heterotrophic bacteria counts were estimated employing the pour-pl ate method, the membrane filter technique, for total coliforms, fecal colif orms, enterococci and Pseudomonas spp., and the most probable number method for sulfite-reducing clostridia, Overall 170 paired samples were tested. E ndotoxin concentrations were assayed in treated water samples, by the Limul us Amebocyte Lysate method, employing a chromogenic substrate. Endotoxin co ncentration varied from 0-30 EU/ml and exceeded 5EU/ml in 30.6% of the cent ers. Endotoxin contaminated samples showed higher counts of total heterotro phic bacteria, fecal coliforms, enterococci and Pseudomonas spp. than the r est of the samples, though the difference was significant only for total he terotrophic bacteria and enterococci, Additionally, samples with endotoxin contamination derived from the mains water had significantly higher counts of fecal coliforms, enterococci and Pseudomonas spp. Endotoxin concentratio n was correlated with the presence of a deionization system, counts of feca l coliforms in supply water and counts of total coliforms, fecal coliforms and enterococci in treated water. These results demonstrate that hemodialys is centers in Greece need to monitor and preventively maintain the entire h emodialysis system, in order to ensure renal replacement therapy of good qu ality.