It's hard to say without detailed history of medication use and antibiotic
sensitivity analysis lab data. The bacteria strain is very common. It's
called recurrent urinary tract infection. Your mother's case is very severe
one.
For a good introduction to non-medical professional on UTI, please read http://kidney.niddk.nih.gov/kudiseases/pubs/utiadult/index.htm
If you want to know exactly how a good American doctor treat UTI under all
circumstances, and all the medications and procedures. You ca