Indications for urine cultures and susceptibility testing in UTI

Dr Mark Loeb is a professor in the Department of Pathology and Molecular Medicine, division director for Infectious Diseases, and Michael G. DeGroote Chair in Infectious Diseases at McMaster University.

Should antimicrobial treatment in a patient with urinary tract infection (UTI) always be preceded by identification of the etiologic agent and susceptibility testing? What are the indications for performing urine culture?

Mark Loeb, MD, MSc: It’s almost easier to answer this question by saying when you do not need to look for a culture and try to identify and figure out what the susceptibility is.

The major point is that women who are healthy, who present in an outpatient setting with a lower UTI with dysuria, suprapubic pain, and so on do not need to have a urine culture and susceptibility testing done. Those patients can be treated empirically with antibiotics.

However, patients who have a complicated UTI, patients who are very ill, those who are septic should have a culture done, followed up with susceptibility testing.