title: Absence of bacterial imprints on struvite-containing kidney stones: a structural investigation at the mesoscopic and atomic scale.
abstract: OBJECTIVE
  Bacterial imprints are always observed on highly carbonated apatite kidney stones but not struvite kidney stones. Struvite and carbonated apatite stones with a high CO(3)(2-)/PO(4)(3-) rate are believed to develop from infections, but their structural differences at the mesoscopic scale lack explanation.
  
  
  METHODS
  We investigated 17 urinary calculi composed mainly of struvite or carbonated apatite by Fourier transform infrared, scanning electron microscopy, and powder neutron diffraction techniques.
  
  
  RESULTS
  Carbonated apatite but not struvite stones showed bacterial imprints. If the same stone contained both carbonated apatite and struvite components, bacterial imprints were observed on the carbonated apatite but not the struvite part. Moreover, neutron powder diffraction experiments revealed the crystal size of struvite stones were larger than that of carbonated apatite stones (250 ± 50 vs 50 nm).
  
  
  CONCLUSIONS
  Bacterial imprints may appear more easily on kidney stones with small nanocrystals, such as carbonated apatite than with large nanocrystals, such as struvite. This approach may help identify bacteria contributing to stone formation, perhaps with negative results of urine culture.
authors: Laboratoire de Physique des Solides, Université Paris XI, Orsay, France. bazin@lps.u-psud.fr
authors: Dominique
authors: D
authors: Bazin
authors: Gilles
authors: G
authors: André
authors: Raphael
authors: R
authors: Weil
authors: Guy
authors: G
authors: Matzen
authors: Veron
authors: V
authors: Emmanuel
authors: Xavier
authors: X
authors: Carpentier
authors: M
authors: M
authors: Daudon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001031:Apatites / Q000378:metabolism; D002119:Calcium Carbonate / Q000378:metabolism; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry* / Q000382:microbiology / Q000648:ultrastructure; D017616:Magnesium Compounds / Q000378:metabolism*; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D053758:Nanoparticles / Q000737:chemistry; D033363:Neutron Diffraction; D010710:Phosphates / Q000378:metabolism*; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D000069877:Struvite
chemical_list: D001031:Apatites; D017616:Magnesium Compounds; D010710:Phosphates; D000069877:Struvite; D002119:Calcium Carbonate