Thanks for your query.Based on the facts that you have posted it appears that your 64 years old mother who is bed ridden gets repeated episodes of UTi.
This is due to contamination of soaked drapers and cloth on the bed.
This is the problem with the f patients who are bed ridden
In a given situation if she is to remain bed ridden for a long time it will be better to put a supra-pubic catheter to drain her bladder so that her bed will not get soaked with urine and she will be free from UTI.
Discuss this with your family Physician or qualified Urologist