Ureaplasma urealyticum in the upper urinary tracts of renal allograft recipients

Urine samples from 123 renal transplant recipients were cultured for the presence of Ureaplasma urealyticum and other fastidious microorganisms. Ureaplasmas were recovered alone or in association with other microbial species from the bladder urine of 13 (11%) of the 123 patients, and evidence of involvement of the upper urinary tract was present in nine patients. Colonization of the upper urinary tract by U. urealyticum was not associated with a decline in function of the grafted kidney and was found only in patients with a primary diagnosis of reflux nephropathy (50% of such patients were positive for ureaplasmas) or glomerulonephritis (10% were positive) who had their own kidneys. The next most common isolate was Gardnerella vaginalis, recovered from 7% of patients, the majority of whom harbored the organism in the bladder only. The results confirm that U. urealyticum may colonize the upper urinary tracts of patients with proven renal disease.