Infection Stones Research Articles

Urinary Lithiases: Epidemiological, Clinical and Therapeutic Aspects of 164 Cases at Sheikh Zayed Hospital in Nouakchott—Mauritania

Urinary lithiases occupy an important position with respect to urological activities in our department. In our Sahel region, lithiasic pathology represents 40% in urology in Senegal [1]. In Mauritania, we did not find a study evaluating the prevalence of this pathology. The frequency and gravity are variable. The objective of the study was to report the clinical profile and the results of management of urinary lithiasis in our environment. Materials and Methods: We conducted a retrospective, descriptive study spanning over two years (April 2015 to March 2017) in the urology department of Sheikh Zayed Hospital in Nouakchott. All patients operated for urinary lithiasis during this period were included in the study. The operative techniques used were semi rigid ureteroscopy, extra corporeal lithotrity, open surgery. Our center did not have flexible ureteroscopy and percutaneous nephrolithotomy. The indications were lithotrity for calculations lower than 20 mm of low density. Biger than 20 mm were by open surgery. Semi rigid ureteroscopy for distal ureteral calculi. Medical treatment or monitoring for non-obstructive calculi is less than 7 mm. Urine drainage by jj probe or nephrostomy are performed. We excluded all patients with lithiasis for the medical treatment. The result was good when absence of lithiasis residues was less than 7 mm and removal of the obstruction. Results: A total of 164 patients were found. The average age was 41 years, and F/M ratio was 1/10. Considering geographical origin, 82% of patients came from rural areas. The presenting complaint was mainly Lower Urinary Tract Symptoms (56%) and Renal Colicky Pain (31%). The bladder and kidneys were the most common (respective 45% and 35%) sites of stone location. Bilateral stones were 18%. Staghorn stones constituted 6% of the cases. Non steroidal anti-inflammatory treatment was administered in 82% of cases, while antibiotic therapy was administered in 32% of cases. Complications occurred in open surgery about 11% like parietal infection and residual stones. 0.6% of ESWL got uretere obstruction that needed jj catheter. 4% of cystolithotomy had infection. Conclusion: Urinary lithiasis often consults at the complication stage. Minimally invasive techniques are limited in our service and offer less complication.

Hemorrhagic Renal Cyst, a Case Report.

A 73-year-old male presented with one day of hematuria associated with urinary frequency and acute on chronic abdominal cramping. On exam, he had diffuse abdominal tenderness, which he stated was normal for him. He was afebrile with no costovertebral angle tenderness or any other pertinent findings on physical exam. The urinalysis showed large red blood cells and small leukocyte esterase and nitrites. Labs were significant for white blood cell count (WBC) 24.6/mm3, hemoglobin 11.6 g/dL, blood urea nitrogen (BUN) 56 mg/dL, creatinine 3.8 mg/dL (baseline 2.8 six months ago), glomerular filtration rate (GFR) 16 mL/min. These findings were consistent with acute on chronic kidney injury with concomitant urinary tract infection - specifically concerning for pyelonephritis or an infected renal stone. Bedside renal ultrasound demonstrated a right renal cyst with echogenic debris consistent with a hemorrhagic cyst (red arrow). In addition, a computed tomography (CT) scan of the abdomen and pelvis revealed a 4mm non-obstructing right renal stone and bilateral renal cysts. The CT also confirmed the ultrasound finding of a right renal cyst with mild perinephric stranding possibly consistent with a hemorrhagic cyst. Simple renal cysts are typically single, unilateral, and usually possess four distinct characteristics: lack internal echoes, have increased posterior acoustic enhancement, have a uniform round/oval shape, and have thin posterior walls/demarcated borders.1 If all of these ultrasound features are met, additional imaging does not always have to be obtained.1,2 Simple renal cysts are usually benign, asymptomatic, and often appear as incidental findings on imaging.2,3 Generally, the number of renal cysts increase as a person ages.3A renal cyst may be classified as a complex cyst when it fails to be defined as a simple cyst.1 Characteristics of complex renal cysts may include septations, calcifications, internal echoes, or other irregularities.1 Cysts can also become more complex by hemorrhage or infection, which is usually evident on ultrasound by internal echoes.1 Calcifications can also form within the cyst, which can make it challenging to discriminate a simple cyst from cystic renal tumors.2 Both malignant and hemorrhagic cysts often have irregular boarders and echogenic material within their walls and within the cyst.4 On ultrasound, infected renal cysts are characterized by thickened walls sometimes with debris or gas.1,3 Calcifications may be present with increased attenuation.3 Infected cysts are diagnosed by a combination of imaging findings and clinical characteristics.3,5 While simple cysts are usually asymptomatic, malignant or more complex cysts are more likely to be symptomatic.3To further distinguish hemorrhagic cysts from malignant tumors, a CT or magnetic resistance imaging (MRI) should be performed.2 Computed tomography is more sensitive than ultrasound for identifying a renal mass, but ultrasound is effective for further characterizing a simple cyst from a complex cyst.3,6 One study reported that CT, MRI, and MRI with diffusion-weighted imaging (DWI) had 100% sensitivity at identifying the presence of possible malignant renal lesions, but CT and MRI had lower specificity (66.9% and 68.8%) than MRI with DWI (93.8%).7Further classifying the type of renal cyst - simple vs complex or hemorrhagic vs infected vs malignant - aids in guiding management. While simple cysts usually do not need additional imaging, complex cysts may need to be further characterized.2 If malignancy is unlikely, hemorrhagic cysts are typically followed with serial ultrasounds.1 If there is concern for infection, antibiotics should be started.5 Further evaluation may include aspiration and drainage.1. This patient was started on antibiotics and admitted to the hospital. Urology, nephrology, and infectious disease were consulted. He was continued on antibiotics for 3 weeks due to concern for possible infected renal cyst. The patient was discharged and recommended to follow-up with urology for an outpatient cystoscopy and repeat renal ultrasound in 3 months to evaluate for a possible neoplasm. Renal cyst, hemorrhagic cyst, hematuria, bedside ultrasound, POCUS.

Antibacterial effect of fosfomycin tromethamine on the bacteria inside urinary infection stones.

This study sought to evaluate the antibacterial effect of fosfomycin tromethamine (FT) on the bacteria inside urinary infection stones. The internal structures of urinary stones were observed via scanning electron microscopy to verify the presence of internal bacteria. We randomly assigned equal numbers of patients with kidney stones who met the inclusion criteria into two groups in a prospective study and treated them with different perioperative antibiotics. One group (experimental group) was treated with FT, and the other (control group) was treated with cefuroxime sodium. All stone specimens were collected via percutaneous nephrolithotomy (PCNL). The primary infection stones were screened via a stone component analysis, 30 cases in the experimental group and 31 cases in the control group. High-performance liquid chromatography (HPLC)-mass spectrometry was used to measure the drug concentration inside the stones, the bacterial count was calculated via stone culture, and the clinical infection index were monitored for between-group comparisons. Compared with the control group, the experimental group had a higher internal drug concentration, a higher drug sensitivity against various pathogenic bacteria, a lower bacterial colony count in the stone culture, and a lower incidence of postoperative clinical infection. FT is more effective than cefuroxime, which is commonly used during the perioperative period of urinary stones, and exerts a high antibacterial effect on these internal bacteria, and effectively reduces the probability of infection and sepsis after urinary stone surgery. FT can be used as an antibiotic during the perioperative period of urinary stones.

Prosopis Plant Chemical Composition and Pharmacological Attributes: Targeting Clinical Studies from Preclinical Evidence.

Members of the Prosopis genus are native to America, Africa and Asia, and have long been used in traditional medicine. The Prosopis species most commonly used for medicinal purposes are P. africana, P. alba, P. cineraria, P. farcta, P. glandulosa, P. juliflora, P. nigra, P. ruscifolia and P. spicigera, which are highly effective in asthma, birth/postpartum pains, callouses, conjunctivitis, diabetes, diarrhea, expectorant, fever, flu, lactation, liver infection, malaria, otitis, pains, pediculosis, rheumatism, scabies, skin inflammations, spasm, stomach ache, bladder and pancreas stone removal. Flour, syrup, and beverages from Prosopis pods have also been potentially used for foods and food supplement formulation in many regions of the world. In addition, various in vitro and in vivo studies have revealed interesting antiplasmodial, antipyretic, anti-inflammatory, antimicrobial, anticancer, antidiabetic and wound healing effects. The phytochemical composition of Prosopis plants, namely their content of C-glycosyl flavones (such as schaftoside, isoschaftoside, vicenin II, vitexin and isovitexin) has been increasingly correlated with the observed biological effects. Thus, given the literature reports, Prosopis plants have positive impact on the human diet and general health. In this sense, the present review provides an in-depth overview of the literature data regarding Prosopis plants’ chemical composition, pharmacological and food applications, covering from pre-clinical data to upcoming clinical studies.

Effect of (−)-Epicatechin on Poorly Crystalline and Amorphous Precipitate. The Role of Green Tea Compound in the Formation of Infectious Urinary Stones

Infectious urinary stones induced to grow by urease-producing bacteria consist of aggregates of bacteria, highly crystalline struvite, and poorly crystalline and amorphous precipitate (PCaAP). The paper describes an experimental study on the influence of (−)-epicatechin, a green tea component, on the nucleation and growth of PCaAP. The crystallization process of PCaAP was performed in artificial urine, and the activity of bacteria was simulated by the addition of aqueous ammonia solution. The formation of struvite was avoided by using Mg-free artificial urine. Optical microscopy methods and spectrophotometric measurements both confirm that (−)-epicatechin promotes the nucleation and growth of PCaAP. This means that PCaAP nucleation is shifted toward a lower pH compared to the control test. The results of the experiments are explained based on the theoretical analysis of the chemical species formed in artificial urine. This chemical speciation analysis shows that the experimentally observed effects are due to the effect of (−)-epicatechin on the formation of CaCO3, CaHPO4, CaC2O4, CaCit–, and HPO42– species.

A REVIEW ON UROLITHIASIS

Urolithiasis is the urinary disorder characterized by formation of stone in the urinary tract, urinary bladder and kidneys.
 Urolithiasis is considered to be a risk of urinary incontinence and may be associated with urinary incontinence.
 A urinary stone commonly occurs in males and are calculated on the basis of their mineral composition. Approximately 80% of urinary stones composed as calcium oxalate and calcium phosphate. Urinary calculi can cause disruption to the urinary system, hydrophoresis, infections and bleeding. Root stone formation is the result of several mechanisms.
 Whereas exceeding supersaturation (i.e. free stone formation) is the cause of uric acid or cystine calculi, infection stones result from bacterial metabolism. Renal calculi can be broadly classified in two large groups: tissue attached and unattached.
 Components in diet increase the risk of stone formation include low intake of fluid and animal protein, sodium, sugar and syrup high corn fruit, oxalate, grape juice, apple juice and cola drinks.
 Vegetarian diets, spices and liquids may be helpful in treating and prevention and kidney stones. Therefore, the best way to prevent kidney stones is to consume a lot of water and a magnesium rich vegan. Common medications used to prevent urolithiasis do not work for all patients, and many have adverse effects that endanger their long-term use.
 Managing today's urolithiasis with open renal surgery is unusual and rarely used, only by the introduction of Extracorporeal Shock wave lithotripsy (ESWL) is useful but it is expensive.
 Herbs and herbal medicines have created interest among people with its clinically proven effects such as immunomodulation and antimutagenic. Also, abusing synthetic drugs due to serious side effects of the drug has allowed humans to return to nature for safe treatment.
 Kew words: hydrophoresis, Urolithiasis

Aggregation of poorly crystalline and amorphous components of infectious urinary stones is mediated by bacterial lipopolysaccharide

Poorly crystalline and amorphous precipitate (PCaAP) is one of the components of the so-called infectious urinary stones, which are the result of the activity of urease-producing microorganisms, mainly from the Proteus species, in particular Proteus mirabilis. The main component of this kind of stones is crystalline struvite (MgNH4PO4∙6H2O). Bacteria can build into the structure of the urinary stone and, in this way, they are one of the components of the urinary stone. From these three components – PCaAP, struvite and Proteus mirabilis – PCaAP exhibits the greatest ability to aggregate. The present study focuses on the aggregation of PCaAP. In particular, an influence of lipopolysaccharide (LPS) isolated from Proteus mirabilis on aggregation of PCaAP is presented. An aggregation of PCaAP is characterized by cross-sectional area of aggregates and zeta potential. The results demonstrate that, in artificial urine, the influence of freely suspended LPS on aggregation of PCaAP depends on the concentrations of LPS. Small concentrations of freely suspended LPS enhance the aggregation of PCaAP compared to the control test. For high concentrations of freely suspended LPS the formation of aggregates of PCaAP is inhibited. LPS, which is not freely suspended, but covers polystyrene latex beads, has no such properties. The investigations provide evidence for the importance of biological regulation in the PCaAP aggregation process.

The clinical observation of fifth generation EMS pneumatic lithotripsy combined with ultrasonic lithotripsy in the treatment of 22 cases of infectious kidney stones

目的 探讨使用第五代EMS气压弹道联合超声碎石清石术治疗感染性肾结石的临床效果观察。 方法 选取2015年4月至2018年3月在本院收治的22例感染性肾结石患者作为临床研究对象，所有患者均使用瑞士第五代EMS气压弹道联合超声清石系统进行治疗。 结果 所有患者均获成功，一期结石清除率达86.3%(19/22)；平均手术时间为58 min；住院时间为(8.5±2.3)d；术中平均估计失血量为150 mL，术后常规复查KUB，手术效果非常满意，术后2例出现高热，积极抗感染治疗后症状逐渐消失。其他患者未出现感染性休克、出血、损伤周围组织脏器等严重的并发症。 结论 对感染性肾结石患者采取瑞士第五代EMS超声联合气压弹道碎石清石系统进行治疗是安全有效的，能够有效提高结石清石率，减少手术时间，降低并发症，缩短住院时间，值得临床推广应用。

Composition analysis and related risk factors of recurrent upper urinary tract calculi

Objective To analyze the composition and risk factors of recurrent upper urinary tract calculi. Methods From September 2015 to December 2017, 120 cases of recurrent upper urinary calculi in our hospital were selected.The clinical data of all the subjects were analyzed retrospectively.The changes of stone components before and after the recurrence of calculi were analyzed, and the risk factors for the changes of recurrent stones were evaluated. Results Recurrent upper urinary calculi in 120 cases, calcium oxalate stone in 50 cases, calcium phosphate stone in 24 cases, infectious stone in 20 cases, uric acid stone in 10 cases, and cystine stone in 16 cases were found. Eighty patients had unchanged stone composition and 40 patients had changes in stone composition.Patients with recurrent upper urinary tract stones were closely related to stone type, recurrence time and other factors.The difference was statistically significant(P<0.05). Conclusions The main changes of calculus in recurrent urinary calculi are the conversion of calcium oxalate stones and infectious stones.The main risk factors for the change of stone composition are the time of recurrence.Patients with recurrent stone for more than 5 years or less than 1 year need to be rechecked regularly. Key words: Urinary Calculi; Risk Factors

Using Syndromic Surveillance to Quantify ED Visits for Coagulopathy Cases

Using Syndromic Surveillance to Quantify ED Visits for Coagulopathy Cases

Clinical study of ureteroscopy with internally 4F ureteral catheter combined with holmium laser lithotripsy in treatment of ureteral infection stones

Objective To study the clinical value of ureteroscopy with internally 4F ureteral catheter combined with holmium laser lithotripsy in treatment of ureteral infection stones. Methods All 70 patients of ureteral infection stones undergoing holmium laser lithotripsy during January 2016 to March 2018, 36 patients who were treated with ureteroscopy with internally 4F ureteral catheter combined with holmium laser lithotripsy, and 34 patients who were treated with ureteroscopic lithotripsy. The operation date, postoperative infection were observed and compared between the two groups. Results The success rate of the two groups of surgical lithotripsy was 100%. The intra-ureteral pressure of operating, operation time and postoperative hospital stay of ureteroscopy with internally 4F ureteral catheter combined with holmium laser lithotripsy group were lower than that of ureteroscopic lithotripsy group (P<0.05), and postoperative fever, fever continued times were lower than that of ureteroscopic lithotripsy group (P<0.05). Conclusions Ureteroscopy with internally 4F ureteral catheter combined with holmium laser lithotripsy in treatment of ureteral infection stones is safe and effective for the treatment of ureteral infection stones, and can reduce the incidence of postoperative infection. Key words: Ureteral Calculi; Infection; Ureteroscopy; Lasers, Solid-State

MP08-06 THE ASSOCIATION BETWEEN 24-HOUR URINE COLLECTION USE AND STONE RECURRENCE AMONG HIGH RISK KIDNEY STONE FORMERS

INTRODUCTION AND OBJECTIVES:The American Urologic Association Guidelines recommends obtaining a 24-hour urine (24HU) in recurrent stone formers, patients high-risk for stone recurrence, and interested first-time stone formers. However, the advantage of selective therapy based on 24HU results over empiric treatment is unclear. We aimed to determine if obtaining a 24HU in high risk stone formers is associated with decreased recurrent stone episodes in a contemporary cohort exemplifying real-world clinical practice.METHODS:We used the MarketScan database to identify insured, employed subjects, 18 to 64 years old with a primary diagnosis of kidney and/or ureteral stones based on ICD-9 and ICD-10 diagnosis codes from 2008 to 2014. Subjects at high risk for infectious stones or with cystinuria were excluded. High risk stone formers (based on AUA guidelines), those undergoing stone surgery, and those with previous stone diagnoses one year prior to the date of inclusion were characterized with CPT and ICD codes, ...

Antibacterial and In Vitro Growth Inhibition Study of Struvite Urinary Stones Using Oxalis corniculata Linn. Leaf Extract and its Biofabricated Silver Nanoparticles.

Herbal drugs are gaining exponential scientific recognition due to their distinct advantages. In the last 2-3 decades, a gradual increase in worldwide patents on herbal nanoformulations has been noted to address the solubility and bioavailability issues of phytoceuticals. Struvite or ammonium magnesium phosphate hexahydrate (NH4MgPO4.6H2O) is among the important urinary infection stones causing painful urological ailment. These smaller stones may bind together to form bigger staghorn calculus. Urinary tract infections caused by some gram positive and gram negative bacteria further enhance the chance of formation of such stones. Oxalis corniculata Linn. is an edible plant, traditionally used in the treatment of bacterial infections and kidney stones. However, there is no scientific evidence to relate the use of O. corniculata against struvite kidney stones. Hence, the antibacterial and struvite stones inhibition activity of the aqueous extract of Oxalis corniculata Linn. leaves and its biofabricated silver nanoparticles (AgNPs) was studied. The aqueous extract of O. corniculata was prepared by Soxhlet extraction. AgNPs were synthesized using green technique and were characterized using UV and IR spectroscopy, XRD, TEM, DLS and zeta potential studies. Antibacterial activity of the aqueous extract and the silver nanoparticles was tested against E. coli (gram negative) and S. aureus (gram positive) species. Struvite stones were grown in a gel medium by in vitro single diffusion gel growth technique and its inhibition study was carried out using the extract and its biofabricated nanoparticles. The aqueous extract and its biofabricated AgNPs exhibited potent antibacterial activity against both gram positive and gram negative strains of bacteria. The aqueous extract also effectively repressed the growth of struvite stones and led to the dissolution of stones, but the inhibitory effect was further enhanced by its biofabricated AgNPs. The present work confirms the inhibitory activity of the aqueous extract of edible O. corniculata and its biofabricated silver nanoparticles against urinary tract infection (UTI) causing bacteria and urolithiasis. Therefore, the consumption of O. corniculata in our daily diet may reduce the risk of UTI and urolithiasis.

Formation of Poorly Crystalline and Amorphous Precipitate, a Component of Infectious Urinary Stones: Role of Tetrasodium Pyrophosphate

The present study concerns an important topic regarding the search for new, improved, and effective methods of preventing the development of infectious urinary stones. In this article, the effect of tetrasodium pyrophosphate (TSPP) on the formation of a poorly crystalline and amorphous precipitate in artificial urine in the context of infectious urinary stone formation is studied. The spectrophotometric results suggest that TSPP presence shifts the formation of the poorly crystalline and amorphous precipitate (PCaAP) toward lower pH, which means that PCaAP is formed earlier. In other words, TSPP promotes the formation of PCaAP. Additionally, TSPP causes the formation of calcium pyrophosphate. These results are confirmed by X-ray diffraction and energy dispersive X-ray studies. The experimental results obtained are explained on the basis of theoretical chemical speciation analysis of chemical complexes formed in artificial urine.

Preoperative Prediction of Infection Stones Using Radiomics Features From Computed Tomography

Preoperative prediction of infection stones from CT images could provide additional information for treatment planning. We developed a radiomics algorithm that could apply data from non-contrast-enhanced CT images to distinguish infection stones from non-infection stones. This retrospective study included 98 patients with clinically confirmed infection kidney stones and 59 patients with non-infection kidney stones. Fifty-four radiomics features extracted from CT images were reduced to 27 key features by the LASSO algorithm, for which a radiomics signature was built with ensemble learning based on bagged trees. Multivariable logistic regression analysis was then used to develop a radiomics nomogram incorporating the radiomics signature and independent clinical factors. The radiomics signature, which consisted of morphological features and textural features, was significantly associated with infection kidney stones. Ensemble learning based on bagged trees could differentiate infection kidney stones from non-infection kidney stones with 90.7% accuracy, 85.81% sensitivity, 93.96% specificity, a 91% positive predictive value and a 91% negative predictive value. Predictors incorporated into the individualized prediction nomogram included the radiomics signature, white blood cell count and urine culture. Decision curve analysis demonstrated that the radiomics nomogram had potential clinical application for infection stone prediction.

Role of Agropyron Repens Extract in Treatment Renal Calculus in Pediatric Group

Background: Renal, urologic, endocrine, and metabolic disorders can lead to the progress of crystallized substance in the urinary system. Infected stones may produce renal colic, hematuria and sepsis. Agropyron repens has pharmacological action as soothing mild diuretic, demulcent, antimicrobial, antioxidant objective: a prospective randomized controlled study the efficacy of Agropyron repens in decrement number and size of renal calculus and its clinical feature in pediatric group. Patients and Method: 50 Child between 5 to 14 years old suffering renal calculus from 3 September 2017 to 24 march 2019 in the salahaldeen hospital and personal doctor’s office, 25 case as Agropyron group and 25 case as control group. Agropyron repens extract (capsule) 5 mg /kg as single dose every other day for 60 days dissolved in water while control group given supportive treatment. Guide by sequential ultrasonic urinary examination every 14 days liver function with renal function and hematological study were done and evaluated for any abnormality and/or side effect. Results: Agropyron repens group were demonstrate significantly decline in number and size of stones 22 (88%)± 2.12 (P= 0.001) , 23 (92%)±1.031 (P=0.003) more than control group 2 (8%)±1.02 (P = 0.12), 4 (16%)±1. 41 ( P = 0.11) respectively and Agropyron group was illustrating mean±SD significantly reduction in renal colic was (77.6%) %) (19. 4 ± 1.72) which was more than in control group (16 %) (4. 1 ±1.02) (P= 0.003).The mean±SD significantly higher reduction in hematuria of Agropyron group (85.96 %) (21.49±1.03) which was more than in control group (24.16%) (6.04±1.06) (P= 0.002). The mean±SD reduction in Sepsis of Agropyron group (88.8%) (22.2 ±1.9) which was more than in control group (12.8%) (3.2± 1.02) mg/dL (P = 0.001). Conclusions: This study indicates importance of Agropyron repens in decrement number and size of renal calculus and diminishes of renal colic, hematuria and sepsis without any side effect in pediatric group

Management and outcome of obstructive ureteral stones in the emergency department: Emphasis on urine tests and antibiotics usage

BackgroundKidney stone related complaints in the Emergency Department (ED) are common. Current guidelines recommend antibiotic therapy for infected obstructive stones and stone removal in a timely fashion, but there is no clear recommendation for prophylactic antibiotic use for bacteriuria or pyuria in the setting of obstructive ureteral stones. ObjectivesThe aim of this study is to evaluate the current management of patients with obstructive ureteral stones in a single ED with emphasis on urine tests and antibiotics use. MethodsThe picture archiving and communication system (PACS) was used to filter the list of patients who received a computed tomography (CT) scan of the abdomen and pelvis that positively identified obstructive ureteral stones. Demographics and clinical data were also recorded and analyzed. ResultsOf the patients discharged, 278 patients did not receive antibiotics in the ED or a prescription. Of these, 8 patients had positive culture, 4 patients followed up, and one developed and was treated for a urinary-tract infection. One hundred ninety two patients were not given antibiotics in the ED but received an antibiotics prescription, and 4 patients had positive cultures grow. Two followed up and had no infection-related complications. Fourteen patients were discharged without a prescription after receiving a single dose of antibiotics in the ED, with no positive urine cultures and 9 patients following up without complication. ConclusionAntibiotics were given at the discretion of the provider without clear pattern. A high rate of infectious complication did not occur in the followed up patient group.

The correlation of crystalline and elemental composition of urinary stones with a history of bacterial infections: TXRF, XRPD and PCR-DGGE studies

The aim of this study was to analyze the correlation between past bacterial infections and the type and chemical composition of urinary stones experienced by human patients. Bacteria have been recognized to contribute to urinary stones; however, the role of uropathogens in the development of specific stones has not been extensively investigated. The detection of past bacterial infection (eleven different bacterial species) in urinary stones from 83 patients was made on a DNA level using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) and correlated with the chemical composition of urinary stones measured using X-ray powder diffraction (XPRD) technique and their elemental composition by total reflection X-ray fluorescence (TXRF). In this study, two scenarios of urinary stones formation mediated by Proteus sp. or Escherichia coli are presented. The first one is associated with Proteus spp. which dominated in 84% of infectious urinary stones and is strongly correlated with struvite and calcium phosphate, in whose matrix additionally strontium, phosphorus, potassium, nickel and zinc are detected. The formation of these stones is closely correlated with urease activity. The second scenario for urinary stone mineralization is associated with E. coli identified in weddellite stones, in which matrix iron was detected. In conclusion, the statistical correlations of bacterial infections with crystalline and elemental composition showed that in mixed bacterial infections, one scenario dominated and excluded the second one.

Current insights into the mechanisms and management of infection stones.

Infection stones are complex aggregates of crystals amalgamated in an organic matrix that are strictly associated with urinary tract infections. The management of patients who form infection stones is challenging owing to the complexity of the calculi and high recurrence rates. The formation of infection stones is a multifactorial process that can be driven by urine chemistry, the urine microenvironment, the presence of modulator substances in urine, associations with bacteria, and the development of biofilms. Despite decades of investigation, the mechanisms of infection stone formation are still poorly understood. A mechanistic understanding of the formation and growth of infection stones - including the role of organics in the stone matrix, microorganisms, and biofilms in stone formation and their effect on stone characteristics - and the medical implications of these insights might be crucial for the development of improved treatments. Tools and approaches used in various disciplines (for example, engineering, chemistry, mineralogy, and microbiology) can be applied to further understand the microorganism-mineral interactions that lead to infection stone formation. Thus, the use of integrated multidisciplinary approaches is imperative to improve the diagnosis, prevention, and treatment of infection stones.

Impact of bacteria on aggregation of crystalline and amorphous components of infectious urinary stones

Infectious urinary stones consist of an agglomerate of bacteria, highly crystalline struvite, and poorly crystalline and amorphous precipitate (PCaAP). The paper describes an experimental study on the agglomeration of PCaAP in the presence and absence of bacteria of the Proteus mirabilis species, in which blind studies are done with bacterial macromolecules with and without lipopolysaccharide. The formation of struvite is avoided by using Mg-free artificial urine. Optical microscopy methods and zeta potential measurements both confirm that the bacterial lipopolysaccharides are the key factors promoting agglomeration, besides the bacterially induced pH change which leads to precipitation in the first place.