The microbiome of calcium-based urinary stones.

Historically, the role of bacteria in urinary stone disease (USD) has been limited to urease-producing bacteria associated with struvite stone formation. However, growing evidence has revealed bacteria associated with stones of non-struvite composition. These bacteria may be derived from either urine or from the stones themselves. Using 16S rRNA gene sequencing and an enhanced culture technique (EQUC), we identified the urine and stone microbiota of USD patients and then determined if bacteria were statistically enriched in the stones relative to the urine. From 52 patients, bladder urine and urinary stones were collected intraoperatively during ureteroscopy. Stone homogenate and urine specimens were subjected to 16S rRNA gene sequencing and EQUC. Standard Chi-squared tests were applied to determine if the relative abundance of any bacterial taxon was significantly enriched in urinary stones compared to urine. Stones were primarily calcium-based. 29/52 (55.8%) stones had bacteria detected by 16S rRNA gene sequencing. Of these, dominant bacterial taxa were enriched from 12 stones. Bacterial taxa isolated by EQUC include members of the genera Staphylococcus, Enterobacter, Escherichia, Corynebacterium, and Lactobacillus. Dominant bacterial genera were enriched compared to paired bladder urine. Differences between the stone and urine microbiota may indicate that certain bacteria contribute to USD pathophysiology. Further investigation is warranted.

Urolithiasis. 2019 Jun 25 [Epub ahead of print]

Ryan A Dornbier, Petar Bajic, Michelle Van Kuiken, Ali Jardaneh, Huaiying Lin, Xiang Gao, Bodo Knudsen, Qunfeng Dong, Alan J Wolfe, Andrew L Schwaderer

Department of Urology, Loyola University Medical Center, Maywood, IL, USA., Department of Urology, University of California at Los Angeles, Los Angeles, CA, USA., Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA., Department of Public Health Sciences, Center for Translational Research and Education, Stritch School of Medicine, Loyola University Chicago, 2160 S First Ave., Bldg. 115, Room 459, Maywood, IL, 60153, USA., Department of Urology, The Ohio State University, Columbus, OH, USA., Department of Public Health Sciences, Center for Translational Research and Education, Stritch School of Medicine, Loyola University Chicago, 2160 S First Ave., Bldg. 115, Room 459, Maywood, IL, 60153, USA. ., Department of Microbiology and Immunology, Center for Translational Research and Education, Stritch School of Medicine, Loyola University Chicago, 2160 S First Ave., Bldg. 115, Room 224, Maywood, IL, 60153, USA. ., Division of Nephrology, Department of Pediatrics, Indiana University, 699 Riley Hospital Dr., RR 230, Indianapolis, IN, 46202, USA. .