What organism is commonly associated with the formation of kidney stones?

The organism commonly associated with the formation of kidney stones is Proteus. This bacterium is known for its urease activity, which hydrolyzes urea into ammonia and carbon dioxide. The ammonia increases the pH of the urine, leading to the precipitation of calcium and magnesium salts, often resulting in struvite stones (magnesium ammonium phosphate stones). Struvite stones typically form in the presence of a urinary tract infection caused by urease-producing organisms like Proteus.

In contrast, the other organisms listed do not have a direct association with the formation of kidney stones. Escherichia coli, although a common pathogen in urinary tract infections, does not produce urease and is not linked to stone formation in the same way. Gardnerella vaginalis is primarily associated with bacterial vaginosis and is not known for affecting kidney stone formation. Staphylococcus aureus is a pathogen related to various infections but is not involved in urease activity and consequently does not contribute to stone formation.