The influence of bacteria in dialysis water on its endotoxin level

The influence of bacteria in dialysis water and its endotoxin level is one of the main important issues of purified water for haemodialysis. The current methods, assessing the number of water bacteria, are insufficient; due to their large diversity, only a small fraction of them grow on our used culture agars. Bacterial cells are classified into three categories: the A cells represent cultivable cells, B cells are living though not cultivable whereas the C cells are dead cells. Methods assessing these different cell categories are discussed. Endotoxin is only released from the C-type cells and is removed by the Reverse Osmosis membranes. It is our task to ensurethat we keep the A-cell level low after the Reverse Osmosis. The purified water must not remain very long in the pipe system and the use of Permeate tanks should be avoided.