Commonest type of Renal stone seen in cases of UTI is:

Answer is A (Phosphate): Phosphate stones (Triple phosphate stones) form in the presence of high concentration of ammonia which essentially means that they form when the urine is infected (UTI) with Urea splitting organisms (eg. Proteus, Kleibsella, Pseudomonas Nil, ) Triple Phosphate Stones (Phosphate stones) Triple phosphate stones are composed predominantly of magnesium ammonium phosphate (strurite) with variable amounts of calcium phosphate. They form in the presence of high urinary concentration of ammonia (bicarbonate and carbonate) They form in cases of UTI when urine is infected with urea splitting bacteria i.e. Proteus, Kleibsella and Pseudomonas They form in urine with an alkaline pH. Urea splitting organisms split urea to ammonia there by providing an alkaline pH which facilitates precipitation of phosphate crystals.