Traditionally, UTI diagnosis has been dependent on urine culture, urinalysis and clinical symptoms. But a recent study casts some doubt on the utility of urine cultures.
A study in the Journal of Clinical Microbiology did urine cultures and E. coli PCR in 220 women with UTI symptoms and 86 women without UTI symptoms.
In the symptomatic women, 67% had positive E. Coli PCR and 98% had a pathogenic bacteria in their urine culture.
In the asymptomatic women, 10% had positive E. coli PCR and/or urine culture.
Therefore, this study suggests that urine culture may be of limited utility, since symptoms alone seemed to predict bacteriuria.
References:Burd EM, Kehl KS. A Critical Appraisal of the Role of the Clinical Microbiology Laboratory in the Diagnosis of Urinary Tract Infections.Journal of Clinical Microbiology. 2011;49(9 Supplement). doi:10.1128/jcm.00788-11.