Fig. 7
Effects of flow stoppage time and presence of metal corrosion on the risk of bacterial contamination of the metal parts of the dialysis pump. Dialysate spiked with P. aeruginosa (10 CFU/mL) was introduced into the experimental circuit (Fig. 1), and the circuit flow was stopped for the indicated periods. Then, after cleaning and disinfection, as shown in Fig. 4, the pump was disassembled, the bacteria on the metal parts were released by ultrasonic exposure, and the released bacteria were counted. The minimum detection sensitivity is 1 CFU. ● indicates not detected; ○ indicates detected; and the dashed lines indicate mean value. ** p < 0.01 (Bonferroni’s test). NS, not significant (Wilcoxon’s test)