Lithiases d'infection

“Infection lithiasis” refers to calculi that occur with persistent urinary tract infection. Stones composed of magnesium ammonium phosphate (struvite) and carbonate apatite, called “triple phosphate” stones, are the more common type of infection lithiasis. These stones are also called “staghorn” calculi because they may grow rapidly and fill the entire collecting system. They form during urinary infection with urea-splitting micro-organism. They may originate de novo or complicate a lithiasis when pre-existing stones are colonized with urea-splitting bacteria. They represent about 2-3 % of stones referred for laboratory analysis. This article reviews the epidemiology, pathogenesis, clinical features, and management of struvite stones. A singular pathologic entity recently described, called “encrusted cystitis or encrusted pyelitis”, mainly caused by Corynebacterium urealyticum is also review. Infection lithiases caused by non-urease-producing bacteria may also occur and are examined in this article. Finally, the controversial role of nanobacteria in nephrolithiasis is discussed.