Isolation of Trichosporon in a hematology ward

During mycologic monitoring of the air in a hematology ward, we found massive air contamination caused by Trichosporon asahii, both in the room where neutropenic patients were staying and the corridor immediately outside the room. This fungal species had never been isolated in previous samplings. The urine culture taken from one of the patients in this room, whose urinary catheter had been removed immediately prior to air sampling, resulted positive for T. asahii. Both macroscopic and microscopic morphologic observation was insufficient for confirming the hypothesis of a close relationship between the strains isolated from the patient, from the air in the room and corridor. Therefore, we used genomic typing with random amplified polymorphic DNA (RAPD). The five primers used, (GTG)(5), (GACA)(4), M13, OPE01, RC08, produced different patterns of polymerase chain reaction (PCR) products; the genomic profiles obtained with the same primer, however, resulted perfectly superimposable for all the strains. This result led us to conclude that the massive air contamination caused by T. asahii can have effectively been determined by the removal of the urinary catheter from the patient who presented an asymptomatic infection caused by this microorganism.