Aerococcus urinae: a possible reason for malodorous urine in otherwise healthy children

Recently, Aerococcus urinae, primarily recognized as a common pathogen in elderly women, has been reported to cause an extremely unpleasant odour of the urine in paediatric patients similar to trimethylaminuria (fish odour syndrome). Herein, we present a case of A. urinae urinary tract colonization in a 12-year-old otherwise healthy boy, who finally refused micturition outside from his home environment as a result of the unpleasant odour. Within the last year, three cases (including our own) of A. urinae colonization causing foul-smelling urine in healthy children have been published, suggesting that this condition might be as frequent as trimethylaminuria. In case of polymicrobial growth in a urine specimen, A. urinae as the leading pathogen will usually be missed by routine bacteriological investigation. Novel bacteriological techniques such as MALDI-TOF MS provide a rapid tool to recognize this pathogen in urine.

As treatment of A. urinae infection is simple, we recommend that in healthy children with malodorous urine, this pathogen is excluded before the initiation of costly metabolic investigations.