Nitrite test in pseudomonas aeruginosa urinary tract infections

Pseudomonas aeruginosa (PA) is considered to be bacteria with a low capability to produce nitrite. Objective: To investigate the incidence of a positive urine nitrite test in community-acquired urinary tract infections (UTI) in children, caused by PA. Methods: The medical records of 38 children (18 females) admitted for febrile PA UTI during a period of 7 years were reviewed. Urine nitrite tests were carried out using dipstrips, and results were reported as positive or negative. Results: Of the 38 patients, 17 had a positive nitrite test and 21 had a negative test (proportion of positive 0.45, 95% confidence interval 0.29 to 0.61). Pyuria was detected in 13/17 patients with a positive nitrate test vs. 5/21 with a negative test (p=0.003). Data regarding renal ultrasound (US) were available for 35 patients, and in 20 abnormalities were detected, 14/17 in the positive vs. 6/18 in negative nitrite group (p=0.001). Conclusion: The urine nitrite test may be positive in PA UTI, therefore, a positive test does not rule out Pseudomonas UTI.