struvite and Bacterial-Infections

Infectious urinary stones make a serious medical problem concerning up to 20% of population. Additionally, recurrence after treatment reaches 50%. The formation of infectious urinary stones is connected with urinary tract infection with various bacteria. These are mainly the bacteria from Proteus species which have been isolated in 70% of bacteriainduced urinary stone cases. These microorganisms produce urease - a bacterial enzyme which plays a principal role in the crystallization process and is one of the main virulence parameters of these bacteria. The most common solid components of infectious urinary stones are the crystals of struvite and amorphous carbonate apatite. The formation of this kind of stones involves two main processes. The first one is the nucleation process of solid phases and the second is the aggregation of the precipitated phases, both crystalline and amorphous. In recent years, both these processes have been deeply investigated. In particular, different active compounds have been reported as potentially novel therapeutic agents to prevent or inhibit the formation of infectious urinary stones. In addition, there is rich scientific evidence regarding the chemical mechanisms of inhibitory effect of these active compounds. In recent years, specific interior and exterior structure of struvite and its porous nature have also been reported. In this article, we summarize and discuss recent development in this field of research. The paper concludes with future goals and challenges.

Topics: Animals; Apatites; Bacterial Infections; Humans; Struvite; Urinary Calculi

The classic "infection stone" struvite is formed as a result of metabolic activity of urease-positive bacteria from alkaline urine with pH-values above 7.5. Due to improved infection diagnostics and antibiotic therapy, the occurrence of infection-related urinary stones in the western industrialized world decreases, despite the generally increasing prevalence rates of urolithiasis in these societies. Struvite is often associated with other mineral phases. These accessory mineral phases could indicate other, non-infection-related causes of urinary stone formation. Thus, mineral analysis is always recommended. Struvite stones as well as struvite encrustations on urinary tract implants are characterized by rapid growth. The rapid growth-related embedding of urease-positive bacteria in the crystalline material makes the urinary stone a persistent source of recurrent urinary tract infections. According to the German Society of Urology guidelines on urolithiasis, a patient with the diagnosis "infection stone" should be assigned to the "high-risk" patient group. Complete stone and debris removal, as well as a special metaphylaxis strategy are required to initiate successful stone therapy.

Topics: Acid-Base Equilibrium; Bacterial Infections; Drug Resistance, Microbial; Humans; Magnesium Compounds; Phosphates; Recurrence; Risk Factors; Struvite; Urease; Urinary Calculi; Urinary Tract Infections

Currently, only struvite stones are regarded as deriving from bacteria. Recent work has suggested that calcium-based stones might also have an infectious origin. Nanobacteria, small intracellular bacteria found in human kidney stones, are capable of forming a calcium phosphate shell, and thus could serve as crystallization centres for renal calculi formation. Until now, however, all trials performed to confirm the presence of nanobacteria in human calculi, serum or urine have failed. In a hyperoxaluric rat model, tissue-residing macrophages were able to remove interstitial crystals and thus may not be primarily engaged in defending against micro-organisms, if present.

Topics: Animals; Bacterial Infections; Crystallization; Hemostatics; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Rats; Struvite

Advances in renal lithiasis research have contributed to a better understanding of the many varied factors that contribute to renal calculus formation. Utilizing the newer techniques of ambulatory metabolic evaluation, we can establish a specific diagnosis in 95% of recurrent stone-formers. Since a significant percentage of initial stone-formers will never have a second episode, it is essential to establish the natural history of the patient's stone disease prior to initiating potentially life-long medical therapy. The majority of initial stone-formers can be managed with education concerning modest dietary restrictions and increased fluid intake. For the recurrent stone-former with metabolically active stone disease, it is probably best to design medical therapy to treat the specific urinary chemical abnormality or disease process.

Topics: Acidosis, Renal Tubular; Bacterial Infections; Calcium; Crystallography; Cystinuria; Diuresis; Fluid Therapy; Humans; Intestinal Absorption; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Oxalates; Patient Education as Topic; Phosphates; Recurrence; Risk; Struvite; Uric Acid; Urography

With limited information available, the association among urinary tract infections, urease-producing bacteria and the presence of magnesium ammonium phosphate (MAP) urolithiasis in canines in Thailand requires more study.. This study aimed to investigate the association between demographic characteristics of canines and the presence of MAP urolithiasis in canines, and to evaluate antimicrobial susceptibility patterns of bacteria isolated from canine uroliths.. A total of 56 canines admitted for treatment with surgical removal of uroliths were recruited. Demographic characteristics and clinical chemistry data were recorded. Bacteria isolated from the removed uroliths were identified. Chemical compositions of the uroliths were analyzed by Fourier transform infrared spectrometer. Potential risk factors were determined with univariable and multivariable logistic regression analyses.. Of 56 canine urolithiasis, bacteria were isolated from uroliths of 38 canines (27 MAP and 11 non-MAP) but not from uroliths of 18 canines (5 MAP and 13 non-MAP). The most common bacteria found in nidus of MAP uroliths was. Our results indicate that

Topics: Animals; Anti-Infective Agents; Bacteria; Bacterial Infections; Dog Diseases; Dogs; Drug Resistance, Bacterial; Female; Phosphates; Risk Factors; Struvite; Urease; Urinary Calculi; Urolithiasis

This study presents the results of a 10-year metaphylaxis of 19 former struvite stone formers, each having had 2-3 stone operations. In these patients, urine was acidified with L-methionine (Acimethin) using a dose of three to six tablets 500 mg/day. Every three months, 11 laboratory parameters were checked in 24-hour urine. 6 parameters were determined in serum. In addition, urine samples were tested for infection. Statistical analysis of analytical data, which was supported by computer graphs, provided the results for the urinary parameters. They were described by geometric means and 95% confidence intervals using ANOVA (analysis of variance). During therapy, the mean pH values decreased significantly from 7.5 to 5.5. Signific-ant increases were found in the excretion of citrate, magnesium, potassium, and uric acid. An increase was also found for calcium, which, however, could not be confirmed to be statistically significant (p = 0.08). In serum, changes of parameters could only be registered for calcium and phosphate. However, at all times, total serum concentrations stayed within their normal limits. Three patients suffered occasional infections (16%), only two of them formed recurrent stones (10%). In assessing the efficacy of L-methionine therapy, the drop in urinary pH to acidic values was the most relevant factor for metaphylaxis.

Topics: Analysis of Variance; Bacterial Infections; Calcium; Chemoprevention; Citrates; Citric Acid; Creatinine; Female; Follow-Up Studies; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Longitudinal Studies; Magnesium; Magnesium Compounds; Male; Methionine; Middle Aged; Phosphates; Potassium; Recurrence; Struvite; Uric Acid

In a 3 year period 95 patients with sialolithiasis were studied, giving an annual incidence of 7.3 per 1000 admissions. The male to female ratio was 2.5:1. Salivary gland stones comprised 73.68 per cent (N = 70 patients). Chemical analysis of calculi taken from 88 patients, showed that 89.77 per cent (N = 79 patients) were with phosphate salts stones, 7.98 per cent (N = 7 patients) were with oxalate salts, and 2.27 per cent (N = 2 patients) were with urate salts. Salivary gland infection was present in 91.57 per cent (N = 87 patients) of whom 75.86 per cent (N = 66 patients) and 24.14 per cent (N = 21 patients) were females. A high ambient temperature and dehydration with poor oral hygiene are probable causative factors.

Topics: Adolescent; Adult; Aged; Bacterial Infections; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Iran; Magnesium; Magnesium Compounds; Male; Middle Aged; Oral Hygiene; Phosphates; Salivary Duct Calculi; Salivary Gland Calculi; Struvite; Uric Acid

Topics: Adult; Ammonia; Bacterial Infections; Citrates; Female; Humans; Hydrogen-Ion Concentration; Hydroxamic Acids; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urease; Urinary Calculi

With advanced techniques of scanning and transmission electron microscopy we studied the ultrastructural ecology of bacteria associated with struvite calculi on catheter surfaces, and in the bladder, ureter and renal pelvis. These detailed morphological data indicate that the interstices, core and external surface of such struvite aggregates contain large numbers of bacterial cells that grow as microcolonies and thick biofilms within extensive fibrous organic matrices. These bacterial cells and their secreted products (glycocalyx or biofilm matrix) appear to provide initial foci for crystal development and aggregation of crystals to form macroscopic struvite stones. The protective glycocalyx-enclosed microcolonial mode of bacterial growth also may explain the relative resistance to antibiotics observed in bacteria associated with infection stones.

Topics: Bacterial Infections; Crystallization; Glycoproteins; Humans; Magnesium; Magnesium Compounds; Microscopy, Electron; Microscopy, Electron, Scanning; Phosphates; Polysaccharides; Struvite; Urinary Calculi; Urinary Tract Infections

The formation of some urinary tract stones (struvite stones) is known to be related to infection by urease-possessing microorganisms, such as Proteus sp. and some other bacteria. Ureaplasma urealyticum, a genital mycoplasma, contains also urease and is predominantly located in the urogenital tract. Its significance in the production of human urinary stones has not yet been elucidated. In this study, 135 human calculi obtained by surgery were analysed chemically and were cultured for the presence of conventional bacteria and U. urealyticum, 51 were ammonium magnesium phosphate stones and contained Proteus (27), E. coli (4), Staphylococcus epidermidis (3), Streptococcus D (2), Pseudomonas aeruginosa (1), Staphylococcus aureus (1), Corynebacterium (1), Candida albicans (1). U. urealyticum was isolated in one patient, from two different calculi (left and right) taken after an interval of fifteen days. Different bacteria were isolated from other calculi (oxalate, uric acid). This findings suggest that Ureaplasma urealyticum should be looked for in struvite calculi.

Topics: Bacteria; Bacterial Infections; Calcium Oxalate; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Mycoplasmatales Infections; Phosphates; Struvite; Ureaplasma; Uric Acid

On the basis of routine clinical and laboratory investigations, one or more probable or possible causes of stone formation were established in 27% of upper urinary tract and 98% of bladder stone patients. In the upper urinary tract, causes were usually found for triple phosphate and pure calcium phosphate stones and rarely for pure calcium oxalate stones. Except for cystine stones and largely for triple phosphate stones there was no definite correlation between the composition of stone and causes. Uric acid and urate stones were often not associated with obvious causes, but their demonstration should lead to further investigations. In a small group of recurrent calcium stone formers examined for hypercalciuria, hyperoxaluria, hyperuricosuria, and renal tubular acidosis, positive findings were noted for 65%, but there was no consistent correlation between these findings and the types of stone. Stone analysis is most useful in so far as it identifies or excludes triple phosphate, cystine, and uric acid/urate stones. This may be done by simple chemical analysis. Certain rare components may, however, be overlooked, as will details of stone structure, unless crystallographic methods are employed.

Topics: Bacterial Infections; Calcium Oxalate; Calcium Phosphates; Cystine; Escherichia coli Infections; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Bladder Calculi; Urinary Bladder Neck Obstruction; Urinary Calculi