Mp63-13 Bacteria Trigger Calcium Oxalate Crystal Formation

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology (MP63)1 May 2024MP63-13 BACTERIA TRIGGER CALCIUM OXALATE CRYSTAL FORMATION Reyhaneh Nazarian, Neil Lin, Aaron Celestian, Jeff Gelb, George O'Toole, Gerard Wong, and Kymora B. Scotland Reyhaneh NazarianReyhaneh Nazarian , Neil LinNeil Lin , Aaron CelestianAaron Celestian , Jeff GelbJeff Gelb , George O'TooleGeorge O'Toole , Gerard WongGerard Wong , and Kymora B. ScotlandKymora B. Scotland View All Author Informationhttps://doi.org/10.1097/01.JU.0001009436.52988.91.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Kidney stone disease prevalence is increasing worldwide, but stone pathogenesis is incompletely understood. Approximately 80% of kidney stones are composed of calcium oxalate (CaOx). Recent studies suggest bacteria play an active role in CaOx nephrolithiasis. We hypothesize that uropathogenic bacteria trigger nephrolithiasis via biofilm formation. We aimed to identify evidence of bacteria within calculi and to investigate the effect of biofilm-forming bacteria on the formation and propagation of CaOx crystals. METHODS: A novel combination of high-resolution X-ray microscopy (microtomography / micro-CT) and X-ray fluorescence microscopy (micro-XRF) was employed to visualize the 3-dimensional morphology and substructure of human stones. Separately, CaOx crystals were formed in-vitro in the presence and absence of E. coli and P. aeruginosa, biofilm-forming bacteria frequently observed in stones collected from patients. Confocal and scanning electron microscopy (SEM) assessed crystal (1) size, (2) morphology, and (3) formation kinetics. Raman (RS) and Energy Dispersive X-ray Spectroscopy (EDAX) identified the chemical composition of the formed crystals. A microfluidic kidney model was developed to recapitulate the physiology of the urinary tract. We evaluated the mechanism of CaOx crystallization in the presence of bacteria in this microenvironment. RESULTS: XRF/microCT analysis revealed a complex 3-dimensional stone morphology including a layered architecture, with organic and inorganic layers reminiscent of biomineralization and a uniquely-connected porosity present in each layer individually. SEM showed the morphology of bacteria-influenced crystals significantly differs from controls and revealed rapid clustered aggregation of E. Coli -mediated crystals; RS and EDAX confirmed CaOx crystal composition. P. aeruginosa mediated up to 280% increase in CaOx crystal size over 10 days, with 250% growth rate versus controls. Our 3-dimensional microfluidic kidney model revealed that P. aeruginosa and E. coli secretions significantly enhance CaOx crystallization, growth, and aggregation compared to controls. CONCLUSIONS: Our results suggest that biofilm-forming bacteria significantly promote CaOx crystal growth and aggregation via their secretions. With our novel combined X-ray microscopy technique, locations of bacteria within stones may be identified, as well as putative nucleation sites for stone formation. Collectively, these findings will give more explicit insight into the mechanistic link between bacterial biofilm formation and CaOx nephrolithiasis. Source of Funding: NIH/NIDDK K08DK13248601A NIH/NCATS KL2TR001882UCLA Innovation Award © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e1036 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Reyhaneh Nazarian More articles by this author Neil Lin More articles by this author Aaron Celestian More articles by this author Jeff Gelb More articles by this author George O'Toole More articles by this author Gerard Wong More articles by this author Kymora B. Scotland More articles by this author Expand All Advertisement PDF downloadLoading ...