Crystallization of urine mineral components may depend on the chemical nature of Proteus endotoxin polysaccharides.
Formation of infectious urinary calculi is the most common complication accompanying urinary tract infections by members of the genus Proteus. The major factor involved in stone formation is the urease produced by these bacteria, which causes local supersaturation and crystallization of magnesium and calcium phosphates as carbonate apatite [Ca(10)(PO(4))(6).CO(3)] and struvite (MgNH(4)PO(4).6H(2)O), respectively. This effect may also be enhanced by bacterial polysaccharides. Macromolecules of such kind contain negatively charged residues that are able to bind Ca(2+) and Mg(2+), leading to the accumulation of these ions around bacterial cells and acceleration of the crystallization process. The levels of Ca(2+) and Mg(2+) ions bound by whole Proteus cells were measured, as well as the chemical nature of isolated LPS polysaccharides, and the intensity of the in vitro crystallization process was compared in a synthetic urine. The results suggest that the sugar composition of Proteus LPS may either enhance or inhibit the crystallization of struvite and apatite, depending on its chemical structure and ability to bind cations. This points to the increased importance of endotoxin in urinary tract infections.
Torzewska
Agnieszka
A
Departments of Immunobiology of Bacteria1 and Genetics of Microorganisms2, Institute of Microbiology and Immunology, University of uuLódź, Banacha 12/16, 90-237 uuLódź, Poland#dReceived 19 December 2002 Accepted 4 February 2003.
Stączek
Paweł
P
Departments of Immunobiology of Bacteria1 and Genetics of Microorganisms2, Institute of Microbiology and Immunology, University of uuLódź, Banacha 12/16, 90-237 uuLódź, Poland#dReceived 19 December 2002 Accepted 4 February 2003.
Róźalski
Antoni
A
Departments of Immunobiology of Bacteria1 and Genetics of Microorganisms2, Institute of Microbiology and Immunology, University of uuLódź, Banacha 12/16, 90-237 uuLódź, Poland#dReceived 19 December 2002 Accepted 4 February 2003.
D003460:Crystallization; D006801:Humans; D008070:Lipopolysaccharides / Q000096:biosynthesis / Q000737:chemistry*; D008297:Male; D011512:Proteus Infections / Q000150:complications* / Q000382:microbiology; D011513:Proteus mirabilis / Q000201:enzymology / Q000378:metabolism / Q000472:pathogenicity*; D011514:Proteus vulgaris / Q000201:enzymology / Q000378:metabolism / Q000472:pathogenicity*; D014510:Urease / Q000378:metabolism; D014545:Urinary Calculi / Q000382:microbiology*; D014552:Urinary Tract Infections / Q000150:complications* / Q000382:microbiology
D008070:Lipopolysaccharides; C430212:lipopolysaccharide, Proteus; D014510:Urease