Bacterially Induced Formation of Infectious Urinary Stones: Recent Developments and Future Challenges

Infectious urinary stones make a serious medical problem concerning up to 20% of population. Additionally, recurrence after treatment reaches 50%. The formation of infectious urinary stones is connected with urinary tract infection with various bacteria. These are mainly the bacteria from Proteus species which have been isolated in 70% of bacteriainduced urinary stone cases. These microorganisms produce urease - a bacterial enzyme which plays a principal role in the crystallization process and is one of the main virulence parameters of these bacteria. The most common solid components of infectious urinary stones are the crystals of struvite and amorphous carbonate apatite. The formation of this kind of stones involves two main processes. The first one is the nucleation process of solid phases and the second is the aggregation of the precipitated phases, both crystalline and amorphous. In recent years, both these processes have been deeply investigated. In particular, different active compounds have been reported as potentially novel therapeutic agents to prevent or inhibit the formation of infectious urinary stones. In addition, there is rich scientific evidence regarding the chemical mechanisms of inhibitory effect of these active compounds. In recent years, specific interior and exterior structure of struvite and its porous nature have also been reported. In this article, we summarize and discuss recent development in this field of research. The paper concludes with future goals and challenges. Keywords: Infectious urinary stones, bacterially induced growth, struvite, carbonate apatite, biogenic crystals, Proteus mirabilis.