Hello and welcome to HCM.
Thank you for your query.
I have gone through your query, and I am very astonished to receive such a good query from a non-medical personnel. Although this seems to be a complicated situation, the answer is quite simple.
When a culture of the urine is conducted, a list of medicines are tested against the infection-casuing organism. Their response and intensity are calculated and reported. This is done over a duration of 48 hours (usually). Although this should be given more time to achieve a good response of the tested medication, as some medications response slowly and late, and an average response results, but not always.
This could be the case with Piu. Although the laboratory reported a resistance, your doctor chose to continue with the levofloxacin
, which luckily proved to kill the infection in the given time.
I admire your inquisitiveness and interest in your wife's case. Salute!!
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you.