Bacteriological water quality and biofilm formation in the treatment system of the hemodialysis unit in Tlemcen, Algeria.

Objective: To evaluate and compare the microbiological quality of osmosis water at the distribution loop, at the dialysis generator inlet and to study the prevalence of biofilm in the tubing.

Methods: Microbiological analysis of 20 water loop samples, 10 water samples were taken at the machine entry and 10 pipe segments from tubing connecting the machines to the loop was done.

Results: The bacterial enumeration results of the loop water vary from 90 to 150 CFU/mL, while the average number of bacteria at the entry of the machines was 182 CFU/mL. The counts of the adhered bacteria in the tubing were worrying with rates ranging from 4.30 to 6.74 Log CFU/ cm . Fifty percentage of the strains isolated were Bacillus, followed by Enterobacter cloacae 23.52%, Staphylococcus, and others such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumanii. More than half of the tubing strains were highly formative of biofilm, 13 strains with medium capacity and 10 were weakly.

Conclusion: This study indicates bacterial water contamination. The formation of a biofilm will certainly harm the effectiveness of the various disinfection methods in this unit. Water quality is influenced not only by the high rate of bacterial colonization, but also differences in standards for dialysis water.