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.