Tehran University Medical Journal

Background: The misdiagnosis of urinary tract infection (UTI) may lead to kidney deficiency and even pyelonephritis. Since different species may cause this disease, urine culture (UC) and antibiogram of the isolated species should be performed and results compared to urine analysis (UA) parameters to obtain the best diagnosis.
Methods: The urine specimens from 1509 patients (1195 women and 314 men) were processed for UA, UC and antibiogram. First of all, the sterile urine samples were cultured using differential media, including EMB and blood agar. After 24 hr incubation, the colonies were identified and differentiated by biochemical tests. Antibiograms for all isolated species were determined using Muller Hinton agar. All results obtained from this survey were analyzed using SPSS software.
Results: Of the 1509 samples, 986 (65.3%) were positive for pathogenic bacteria, 170 (17.2%) of which were from men and 816 (82.8%) from women. E. coli was the most prevalent with 591 cases (58.7%), followed by Enterobacter 115 (11.4%) and Klebsiella 88 (8.8%). Data analysis revealed that the correlations between the WBC, RBC, nitrite, crystal, and protein were significantly higher in culture-positive samples. Of the antibiotics tested, isolated species were most sensitive to amikacin and most resistant to ampicillin.
Conclusion: The present study revealed a correlation between pyuria and bacteruria however, it should be noted that the clinical signs and the presence of WBC in urine could not be used to confirm the UTI. In addition, since different bacterial species are able to cause UTI, in order to administer proper treatment while controlling improper use of antibiotics, thorough testing, including UA and UC together with antibiogram, is strongly recommended.