Investigation of atypical microbial agents in patients with sterile pyuria

To determine the frequency of microbial DNA detection in patients with sterile pyuria and evaluate the association of leukocyte count and leukocyte esterase (LE) test results with physicians' treatment decisions.

This prospective cross-sectional study was conducted over two months in the microbiology laboratories of two university hospitals. Urine samples from 201 patients with sterile pyuria (≥ 10 leukocytes/ml and/or LE positivity with negative urine culture) and 180 controls (no growth in culture and no pyuria) were analyzed. Multiplex PCR targeting 14 potential pathogens was performed. Demographic data, PCR results, and physicians' treatment decisions were recorded. Chi-square tests and logistic regression assessed associations between laboratory findings and treatment decisions.

PCR detected at least one potential pathogen in 50.2% of sterile pyuria patients compared to 10% of controls (p < 0.05). Treatment initiation was more frequent in the patient group than in controls (43.3% vs. 30%, p < 0.05). Logistic regression demonstrated that leukocyte counts ≥ 10/ml were significantly associated with PCR positivity (OR = 6.84, p < 0.05) and the physician's treatment decisions (OR = 2.59, p < 0.05). The most common pathogens in patients were Ureaplasma urealyticum (21.9%), Mycoplasma hominis (12.9%), and Gardnerella vaginalis (10.9%), predominantly in adult women with both elevated leukocyte counts and positive LE tests. Although PCR positivity was significantly associated with treatment initiation, the correlation was weak (r = 0.33), indicating that treatment decisions were influenced by additional clinical factors.

Molecular testing detected DNA from Ureaplasma, Mycoplasma, and G. vaginalis frequently in sterile pyuria, particularly in adult women; these findings indicate candidate microorganisms requiring clinical correlation.