Solid Phases Precipitating in Artificial Urine in the Absence and Presence of Bacteria Proteus mirabilis—A Contribution to the Understanding of Infectious Urinary Stone Formation

Abstract

Magnesium ammonium phosphate hexahydrate, called struvite, is the dominant component of infectious urinary stones. In addition to struvite, infectious urinary stones include solid phases with poor crystallinity as well as amorphous matter. This article is devoted to the analysis of these solid phases, because they have not been characterized well until now. The solid phases tested were obtained from artificial urine in the absence and presence of Proteus mirabilis. The solid phases were characterized by different techniques (X-ray Diffraction, Energy Dispersive X-ray, Scanning Electron Microscopy, as well as Raman and Infrared Spectroscopies). According to the results these phases are carbonate apatite (CA), hydroxylapatite (HAP), amorphous calcium carbonate (ACC), amorphous calcium phosphate (ACP) and/or amorphous carbonated calcium phosphate (ACCP). Carbonate apatite and hydroxylapatite may occur in non-stoichiometric forms, i.e., various anions can be substituted for CO 3 2− , OH − , and PO 4 3− groups in them. The non-stoichiometry of carbonate apatite and hydroxylapatite also implies a deficiency of calcium ions, i.e., calcium ions may be partially replaced by other cations. Experimental techniques and chemical speciation analysis demonstrate that the presence of magnesium influences the formation of CA and HAP.

Deacidification by FhlA-dependent hydrogenase is involved in urease activity and urinary stone formation in uropathogenic Proteus mirabilis

“…Urease activity of P. mirabilis is pH-dependent and loss of hyf or fhlA gene affects urease activity and urinary stone formation. Urease can catalyze the hydrolysis of urea into ammonia, rising pH value and promoting urinary stone formation 27,28 . The urease activity changes with different pH value in Helicobacter pylori, being activated by acidic pH down to pH 2.5 and 3 29 .…”

“…Ampicillin (100 μg/ml), chloramphenicol (40 μg/ml), kanamycin (100 μg/ml), tetracycline (20 μg/ml), streptomycin (100 μg/ml) was added to the medium as needed. Synthetic urine was prepared according to a recipe previously described 27,28 4 Cl, 1.0; urea, 25.0; creatine, 1.1 and tryptic soy broth, 10.0. pH was adjusted to 5.8 and urine was sterilized by passing through a 0.2 μm pore-size filter.…”

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

“…PCaAP is one of the main components of infectious urinary stones. Literature data indicate that the poorly crystalline phases include carbonate apatite Ca 10 (PO 4 ) 6 CO 3 (abbreviated as CA) and hydroxylapatite Ca 10 (PO 4 ) 6 (OH) 2 (abbreviated as HAP) 11,12 . CA and HAP may exist in non-stoichiometric forms, which means that groups CO 3 2− , OH − and PO 4 3− in CA and HAP may be substituted for other anions present in the urine.…”

Effects of Glucose, Metformin, and Protein on Formation of Flower-like Nanocomposites of Struvite in Infected Artificial Urine Medium by Methicillin-resistant Staphylococcus aureus (MRSA): New Report

“…There has [24]. In contrast to mentioned works, artificial urine medium was used by TSB as protein source with variable concentrations of 0.04, 0.3, and 1 g/L [25]. In addition, morphology of these types of stones by SEM and EDX analyses showed laminated, spherical, eggshell-like fragment, and ripple-like shapes of struvites [26].…”