Bacterial Analysis of Kidney Stones Removed by Percutaneous Nephrolithotomy

Study Overview
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Brief Summary
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The aim of this research is to use a controlled laboratory setting to determine whether bacteria isolated from kidney stones of patients play a role in the formation of non-infectious kidney stones. It is well known that struvite stones are associated with active bacterial infection, however the role of bacteria in the formation of non-infection stones (like calcium oxalate) is not well characterized and there are theories that bacteria are involved in the making of these stones.

Detailed Description
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Kidney stone disease is common, affecting nearly 10% of the population with increasing prevalence and increasing cost associated to treat this disease. While struvite stones (composed of magnesium, ammonium and phosphate crystals) have been associated with the presence of infection, the association between bacteria and non-infection stones is not well characterized. Previous studies have found bacteria present in stones of patients without active infection and with negative pre-operative urine tests. There are various compositions of kidney stones, including calcium oxalate, calcium phosphate, struvite and uric acid, with calcium oxalate being the most common. It is well known that struvite stones are associated with active infection, however the role of bacteria in the formation of other types of kidney stones, including calcium oxalate, is not well understood. The investigators hypothesize that bacteria present in the urinary tract of patients without active infection have the ability to facilitate calcium oxalate crystal formation by providing a surface for stones to grow. An understanding of the role of bacteria in the formation of non-infection stones could help prevent stone formation by altering the bacteria present within patients to decrease or eliminate their risk of kidney stone disease.

Official Title
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Bacterial Analysis of Kidney Stones Removed by Percutaneous Nephrolithotomy

Conditions
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Urolithiasis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Over the age of 18 Diagnosed with or have a high index of suspicion of having a kidney stone and scheduled to undergo percutaneous nephrolithotomy. Medically fit for definitive surgical management of stone Exclusion Criteria: Those with medical comorbidities preventing them from safely undergoing definitive surgical therapy. Patients who are unable to provide informed consent. 18 years old or younger Diagnosed with an infection stone Urinary tract infection within 3 months before date of operation Antibiotic use within 3 month before date of operation

Ages Eligible for Study
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Minimum Age: 19 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amount of stone formation in artificial urine with isolated bacteria from non-infection kidney stones compared to control measured using FTIR-Microscopy and SEM (concentration measured in mg/mL). | Bacteria will be isolated from non-infection kidney stones allowed to form a biofilm. Next, the bacteria will be incubated in supersaturated artificial urine to precipitate stone formation in vitro and compared to control urine consisting of the same artificial urine without bacteria. Over time, crystallization in the biofilm will be measured using FTIR-Microscopy and SEM. | Through study completion, approximately 2 years | 
| Bacteria isolated from non-infection kidney stone compared to those identified on pre-operative urine test quantified by simple serial dilution and CFU counting (measured in CFU/mL) and identified using DNA sequencing. | Bacteria will be quantified using simple serial dilution and CFU counting and identified using DNA sequencing. Bacteria will then be correlated with the bacteria identified on pre-operative urine test. | Through study completion, approximately 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Kidney stones, Renal Calculi