I have had my share of UTI's and since I have a kidney transplant, my only option is to get a culture from my doctor.
@cdink1941, @jmaa, @fdan, @erlinda2003, @mmbaluyut

According to Mayo Clinic, a urinary tract infection (UTI) is an infection in any part of your urinary system. Doctors typically treat urinary tract infections with antibiotics. But you can take steps to reduce your chances of getting a UTI in the first place. Here is the health information from Mayo Clinic where you will find symptoms, causes, risk factors, complications, prevention, diagnosis and treatment.
Often, symptoms clear up within a few days of treatment. But you may need to continue antibiotics for a week or more. Take the entire course of antibiotics as prescribed. https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/

Also here are some points about D-mannose that I found on WebMD.
D-mannose is a kind of sugar that is related to glucose. I read that it "might" reduce symptoms of UTI's. However, More evidence is needed to rate the effectiveness of d-mannose for its uses. I also read that D-mannose is POSSIBLY SAFE for most adults when taken by mouth. It can cause diarrhea, loose stools, and bloating. In high doses, it might harm the kidneys.
ome research suggests that d-mannose might make blood sugar control more difficult in people with diabetes.
https://www.webmd.com/vitamins/ai/ingredientmono-1114/d-mannose
I would encourage you to go to the links that I provided to locate the information that will assist you in talking with your doctor about your situation. Be aware, when viewing marketing company sponsored .com sites, that their main goal is sales. So do your research and check with your doctor before you decide on any supplement or medication.