Do you recommend treating asymptomatic Proteus urinary infections in patients with alkaline urine and recurrent calcium phosphate nephrolithiasis?

Yes! Proteus species are typically rapid producers of urease, splitting urea to ammonium and raising urine pH, often into the high 7s and precipitating, magnesium, ammonium phosphate stones, otherwise known as struvite.

Your patient’s Proteus infection apparently splits urea more slowly with less elevation of urine pH and production of calcium phosphate (brushite/apatite) stones.

Suppressing the urinary infection lowers the urine pH, and should slow or stop stone formation. However, you will not be able to eradicate the urinary infection because the Proteus has found sanctuary inside the stone where antibiotics cannot penetrate.

That being the case, it would be reasonable to propose removal of the stone. Then the Proteus infection could be era...

When Proteus is causing stones and alkaline urine, is it via urea hydrolysis? That shows up as high urine ammonia, much above urine sulfate; let's say double the sulfate and often more. With an alkaline urine, kidneys do not do this physiologically. When proteus is in the urine but ammonia levels are not high, everything depends on the stones. Urea hydrolysis results in magnesium ammonium phosphate crystals, whereas calcium phosphate stones are apatite or brushite. So in those patients with culture positive for proteus but no struvite nor high ammonia, treating the proteus is like treating any other infection in a stone former. When infection is clinically an issue, it is usually time to think about removing stone burden, because infected s...