What Does My UTI Culture Test Result Indicate?

Hi my father is 83years old and has UTI culture shows E-coli hes resistant to most of the drugs. Only colistin is sensitive. can i give him Niftran as this is what he has been taking for a while now. FYI hes got a suprapubic cath on for some years now and is prone to urine infection. hes bedridden due to stroke.