INTRODUCTION: In most microbiology laboratories, a urine culture is regarded as contaminated when there is more than one colonial morphotype, thus either it is ignored or a new sample is requested. The isolate is rarely considered significant. OBJECTIVES: In order to study the polymicrobial urinary tract infections, 117 urine samples were selected from inpatients of both genders aged from 14 to 98 years old at Nossa Senhora da Conceição Hospital, Tubarão city, Santa Catarina, Brazil, from August 2003 to January 2004. METHODS: A detailed analysis of patients' records was carried out. Gram test of non-centrifuged urine drop and culture with calibrated loop of 1 or 10 microliters in CLED agar were performed. All cultures were repeated with new urine collection under direct supervision. Physicians waited for the second collection (confirmatory test) to initiate antibiotic therapy. Patients that had started antibiotic therapy immediately after the first collection or those that were using antibiotics were discarded. RESULTS: Six polymicrobial cultures were confirmed from a total of 47 samples with bacterial growth. The results were consistent with clinical indications. CONCLUSION: It is important to emphasize the correlation between laboratory findings and patients' clinical indications. It is recommended that polymicrobial isolates in urine samples from both out-patients and inpatients should be thoroughly investigated.
Polymicrobial urinary, tract infection; Urine Gram uncentrifuged; Urine polymicrobial
