ABSTRACT
Struvite precipitation and urease activity were studied in 72 bacterial strains isolated from patients with an urinary infection. The results revealed struvite precipitation by urease-positive, urease-negative and weakly urealitic bacteria. However, in some strains of each of these groups, no precipitation was observed. Variations in pH within the cultures were also investigated as were the mineralogy and morphology of the crystals precipitated using X-ray diffraction and scanning electron microscopy, respectively. The role of urease activity and alkalinization of the medium in struvite precipitation is discussed, as is the possible involvement of bacteria in nucleation processes. We concluded that urease-negative bacteria or those with weak urease activity may also be involved in the formation of struvite renal calculi although urease-positive bacteria seem to make a greater contribution.
