Evaluation of bacteriological profile of bladder calculi and its association with urinary tract infection in a tertiary health care centre

Abstract

Background: The occurrence of urinary tract infection in presence of urolithiasis (urinary calculi) is frequent. Bladder calculi comprise approximately 5-10% cases of renal or urinary calculi. However, microbial agents of urolithiasis and their association with urinary tract infection are under investigated.Objectives: This study was aimed to evaluate the bacteriological profile of bladder calculi and its association with urinary tract infection.Material & Methods: This descriptive study was conducted in the Department of Microbiology at a tertiary care hospital from September 2018 to September 2019. A sample size of 100 (61 males and 39 females, presenting with bladder calculi) was calculated at 95% confidence interval at 5% acceptable margin of error by Epi Info software version 7.2. Preoperative urine culture and postoperative stone culture were performed. Isolation and identification of bacteria was done using standard microbiological techniques.Results: Urinary tract infection was present in 53% cases which included 26 males and 27 females. The mean age of patients was 42 ± 6.2 years. In majority of cases the reaction of urine was acidic (76%). The most common organism isolated in urine culture was E. coli (28%), followed by Staphylococcus aureus(8%), Pseudomonas aeruginosa (4%), Klebsiellaaerogenes (3%), Proteus mirabilis (2%) and mixed organisms (8%). On bladder stone core culture growth was observed in 50% cases including 22 males and 28 females. The most common organism isolated was E. coli (28%), followed by Staphylococcus aureus (6%), Klebsiellaaerogenes (8%) and mixed organisms (8%). E. coli was the predominant organism found both in urine and core culture of stone.Conclusion: The present study showed that urinary infection was present among majority of cases that presented with bladder calculi and E. coli was the most common type of organism associated. The association of microorganisms isolated from urine and stone core culture was considerable and can predict the source of infective stone. This study highlights the importance of microbiological analysis of stones for complete sterilization of urinary system and prevention of recurrence.