[57] Bacteriological analysis of urinary stones: correlation with preoperative cytobacteriological examination of urine

Objective

To analyse the bacteriological correlation between preoperative cytobacteriological examination of urine (CBEU) and urinary calculi, and to evaluate the impact of chemical nature on the bacteriological stones.

Methods

This was a prospective single-centre study including 42 patients who underwent urolithiasis surgery between January and April 2018. Bacteriological culture of the removed stones was systematic. Mean comparisons were made by the Pearson chi-square test and Fisher’s test for qualitative variables, with statistical significance set at P < 0.05.

Results

The average age of our series was 56 years, with a male predominance of 83.3%. Bladder opening was performed in 45.2% of our patients. The rate of urinary colonisation was 33.3% (14/42). The rate of infected stones was 35.7%. Of the identified pathogens, Escherichia coli was found in 40% of the infected stones, followed by Enterococcus faecalis (20%), and Staphylococcus coagulase negative and Pseudomonas aeruginosa (13.3%). There was a significant correlation (P < 0.001) between preoperative CBEU and bacteriological analysis of the stones. The infected stones were principally calcium oxalate monohydrate and struvite (P = 0.03, P = 0.01).

Conclusion

There is a significant correlation between the bacteriological culture of urinary stones and preoperative CBEU results. A negative preoperative CBEU can guarantee the sterility of urinary calculi in 89.2% for avoiding postoperative infectious complications after surgical manipulation of these stones.