Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic urological condition diagnosed in nearly 8 million females in the United States. Whether urinary microbiota play an etiologic role remains controversial. Most studies assessed the microbiota of IC/BPS patients with voided or catheterized urine as a proxy for bladder urothelium; however, urine may not be a true reflection of the bladder microbiota. Bladder biopsy tissue may provide a more accurate, and thus more clinically relevant, picture of bladder microbiota.
Bladder biopsy tissues were obtained from: (a) 30 females with IC/BPS (18-80 y/o) via cystoscopically guided cold-cup biopsy following therapeutic bladder hydrodistension, and (b) 10 non-IC/BPS females undergoing pelvic organ prolapse repair. To detect bacteria, technical duplicates of each RNAlater-preserved biopsy were subjected to 16S rRNA gene sequencing. To visualize bacteria, paraformaldehyde-fixed, paraffin-embedded biopsies were subjected to a combined multiplexed fluorescence in situ hybridization (FISH) and fluorescence immunohistochemistry (IHC) assay and confocal microscopy.
Bacteria were detected by 16S rRNA gene sequencing in at least one technical duplicate of most biopsies. The most abundant genus was Staphylococcus followed by Lactobacillus; Escherichia was common but not abundant. There was no significant difference between IC/BPS patients and controls (P >.05). Combined FISH and IHC reproducibly detected 16S rRNA in epithelial cells and shed cells in the urothelium and lesioned areas and capillary walls in the lamina propria of human bladder biopsy tissue.
We conclude that urothelial and urinary microbiota are similar but not identical in adult females.
The Journal of urology. 2023 Jan 19 [Epub ahead of print]
Alan J Wolfe, David J Rademacher, Carine R Mores, Robert J Evans, Tyler Overholt, Thomas Halverson, Roberto Limeira, Catherine Matthews, Gopal Badlani, Linda Brubaker, Stephen J Walker
Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois., Current Address: Department of Healthcare Epidemiology and Infection Prevention, Department of Urology/Female Pelvic Health, Wake Forest Baptist Medical Center, Winston Salem, North Carolina., Loyola Genomics Facility, Loyola University Chicago, Maywood, Illinois., Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Diego, La Jolla, California., Current Address: Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland.