Comparison of urine cultures and gram stained smears of urine in diagnosis of urinary tract infections

Abstract

Abstract Background: Different methods are used for diagnosis of urinary tract infections (UTI), however, they have different specificity, sensitivity and time consuming procedures. Objective: To evaluate and comparing the urine culture results with gram stained smears of urine in diagnosis of urinary tract infections. Methods: This research was conducted on 100 hospitalized patients with clinical signs and symptoms compatible with UTI. Urine cultures and gram staining were performed on urine samples of all patients. Findings: Urine culture was positive in 75 (75%) of patients. Gram stained smears on urine sediments were positive in 68 (68%) of patients. Sensitivity, specificity and positive predictive value of gram staining were 85%, 84% and 94% respectively. Conclusion: Gram stained smears of urine, as a diagnostic assay for UTI, is not as sensitive as urine cultures, but it takes only a few minutes to be performed, comparing with urine culture which takes several days.