In vitro and in vivo study of stone formation by Corynebacterium group D2 (Corynebacterium urealyticum)

Abstract

Corynebacterium group D2 inoculated into normal human urine formed struvite crystals and an increase in pH and ammonium concentration after 24 h of incubation. Zinc disks dipped into a broth culture of this microorganism and inserted into the bladders of rats produced stones with a mean weight of 12.5 mg (ranging from 1 to 57.7 mg) after 12 days. Analysis of the infrared spectrum determined the stones to be composed of struvite. From these results its seems that stone formation by Corynebacterium group D2 may be possible both in vitro and in vivo, which may confirm a previous report involving these bacteria in human clinical encrusted cystitis.

Renal failure due to encrusted cystitis and pyelitis

“…Other complementary treatments include urine acidification. Urease produced by bacteria hydrolyzes urea to ammonia and carbon dioxide, causing alkalization of urine 14 . At high pH, precipitation of NH4 + with magnesium and phosphate is promoted to form struvite, and precipitation of carbonate with phosphate form carbonate‐apatite.…”

Carbonate apatite nephrolithiasis associated withCorynebacterium urealyticumurinary tract infection in a dog

“…15,16 Its urease activity leads to high amounts of ammonium and subsequent alkalinisation of the urine, resulting in hypersaturation with ammonium magnesium phosphate (struvite) and calcium phosphate, which predisposes affected patients to encrustations on urothelial surfaces and uroliths. 12,17 In humans, alkaline-encrusted cystitis, alkaline-encrusted pyelitis and nephrolithiasis have been described as complications of C. urealyticum UTIs. [18][19][20] In dogs, only nine cases of C. urealyticum UTIs have been reported, five of which additionally developed encrusted cystitis and/or cystoliths; neither nephrolithiasis nor encrusted pyelitis has been described to date.…”

The conservative management of Corynebacterium group D2 encrusted pyelitis

“…CGD2, a skin commensal microorganism, is responsible for most reported cases of EP, sometimes in association with encrusted cystitis or acute pyelonephritis [ 1, 2]. To establish the diagnosis, prolonged cultures (for 48 or 72 h) on media enriched with 5% CO 2 and sheep blood agar are necessary [ 4, 7]. CGD2 adheres well to uroepithelial cells [ 23], which might explain the retrograde access to the pelvicalyceal system and the presence of mucosal encrustation.…”

“…CGD2 adheres well to uroepithelial cells [ 23], which might explain the retrograde access to the pelvicalyceal system and the presence of mucosal encrustation. As with other urealytic microorganisms, CGD2 releases large amounts of ammonia, increasing urinary pH to alkaline values [ 7, 24]. The infected urine causes precipitation, resulting in wall encrustation and possibly pelvicalyceal stones.…”

“…CT and ultrasonography show high‐density edging lesions of the collecting system, while plain abdominal films are normal or show some calcification of the kidney area [ 5, 6]. EP is most often caused by Corynebacterium group D2 (CGD2), which is a slow‐growing Gram‐positive aerobic and urealytic micro‐organism that does not form spores [ 7–9]. CGD2 urinary tract infections are usually nosocomially acquired, after urological manipulations, and are associated with immunosuppression in many cases [ 10–13].…”