A 60 years old woman has Urinary tract infection. Investigations:- E. coli microorganisms obtained from urine culture. Marked deficiency of estrogen. Past History revealed chronic recurrent infections with these microorganisms.

20 years back she took HRT which was stopped due to complications of diabetes mellitus and dyslipidemia. 5 years ago she was hospitalised for acute pyelonephritis. Her mother died with breast cancer. How to manage this case of recurrent UTI?