My father had a laser holmeum surgery for Prostate problem and he contracted an UTI infection from the catheter. This infection was detected to be Pseudomonas Aeruginosa and my father had already taken Niftran 100 mg twice daily for 3 months. The recent urine culture showed that Niftran is now resistant along with many other antibiotics and his infection is still active. The pus cells were 25 to 30 in the routine microscopy. The only sensitive antibiotic was Colistin. Our doctor is advising to wait for few more days as he is asymptomatic. He is also diabetic from the last 11 years. Please suggest.