Thanks for your query.Based on the facts that you have posted it appears that you have undergone Renal Transplant in 2007 and your one kidney
has been removed for repeated episodes of infection.
Since you are on immuno supresant drugs following transplant it leads to diminished difence of body resistance to any infection .As such it is always difficult to control UTi especially in females once its sets in, as bacteria always go on changing their nature and become resistant to antibiotics.
Please take prophylactic antibiotic like Norfloxacin
Ensure to drink more water.