RESUMO
To determine the prevalence of infected stones in the urinary tract and their relationship to urease positive bacteria and whether a positive urine culture signifies infected stone profile. This study was conducted on 168 patients [116 males and 52 females] with a mean age of 37 years. The analysis was performed on: [1] Urine specimen before operation, [2] Urine around the stone before stone retrieval and [3] Stones. Urine and stone culture was performed on blood agar [BA] and Eosin Methylene Blue [EMB] for gram staining, Brucella agar enriched with vitamin K and Thioglycolate medium for anaerobics and uroplasma urealyticum inside PPLO culture. Urease was determined on urea broth and urea agar media. Chemical analysis of the stone was done by Merck kit. Seven cases of culture were positive for infected stones [64%] while 6 cases of non-infected stones grew microorganisms [3.8%]. Infected stones comprised 6.5% of all the stones. Proteus mirabilis and Pseudomonas aeruginosa were the most commonly encountered bacteria [18%]. Urease positive bacteria were found to be 54.5% in the infected stones and 6% in the non-infected stones. Urine and stones samples showed that only 14.5% had the same type of bacteria. Other factors besides bacteria play a role in stone formation in the urinary tract and infected stones can be produced in non-infected urine also