Cell wall deficient bacteria as a cause of idiopathic hematuria

Idiopathic hematuria in the absence of bacteriuria is a medical challenge. Routine cultures of catheterized bladder and endoscopically obtained ureteral urine specimens from a 22-year-old woman with a 6-week history of hematuria showed no growth after 24 to 48 hours of incubation. However, bacterial variants were grown on enriched media. Colonies were typical cell wall deficient/defective bacteria. Phase and electron microscopy of cystoscopic urine specimens obtained by retrograde ureteral catheterization as well as phase microscopy of the cultures revealed the classic morphology of these organisms. When the variant cultures were subcultured the organisms reverted to their related walled forms, that is Streptococcus agalactiae and Staphylococcus haemolyticus. Because the colonies of these organisms showed various patterns of biochemical reactivity, each phenotype was tested against 15 antimicrobials. Collectively, all biotypes had a common susceptibility to only nitrofurantoin. The patient was treated with nitrofurantoin for 6 weeks. Four days after initiation of therapy she had complete remission of hematuria. During the next 3 years she remained well and free of hematuria.