MYCOPLASMA-HOMINIS, A RARE CAUSE OF ACUTE PYELONEPHRITIS

History and clinical findings: A 23-year-old woman was admitted with t ypical signs of an acute urinary tract infection: fever, pain on tappi ng over both renal areas and in both flanks, urgency and dysuria. She had a history of renal colic with spontaneous passage of a renal stone . Investigations: There was marked leukocytosis and raised C-reactive protein, leukocyturia and haematuria, but no nitrites or protein in th e urine. All blood and urine cultures were sterile and renal ultrasoun d was unremarkable. Diagnosis, treatment and course: As signs and labo ratory data indicated acute pyelonephritis (PN) she was treated with g yrase inhibiting antibiotics. But while symptoms improved, fever, leuk ocyturia and haematuria continued; no microorganism could be demonstra ted. Mycoplasma was therefore considered as a rare cause of PN. Specia l urine cultures then grew M. hominis, > 10(5) organisms/ml. On the ba sis of sensitivity tests doxycycline was administered. All symptoms qu ickly improved and all inflammation parameters and urine sediments bec ame normal. Conclusion: In rare instances M.hominis may be isolated as the causative organism of PN. If, in cases with appropriate symptoms, routine tests fail to demonstrate the causative agent, M. hominis sho uld be included in the differential diagnosis.