RAPD TYPING OF ASPERGILLUS-FUMIGATUS STRA INS - EPIDEMIOLOGIC APPLICATIONS ON A HOSPITAL SITE

During an outbreak of invasive aspergillosis occurring in a bone marro w transplant Unit, 45 strains of Aspergillus fumigatus were collected between January 1993 and October 1994: 31 originated from 24 patients and 14 strains were isolated from air or surface samples. All strains were typed by the Random Amplified Polymorphic DNA (RAPD) analyse usin g 2 primers for each typing. Twenty-six different profiles were identi fied. The 31 patients strains were distributed into 22 different types . Two of them (type C and D) were present in 2 and 4 patients respecti vely. Patients with type D strains were more clustered in time than th ose with type C strains. One of the 14 environmental strains shared ty pe D pattern and 8/14 shared type C. None of these 26 patterns was fou nd in any of 13 other strains isolated over the same period of time in another haematological unit of the hospital. RAPD molecular typing pr oved efficient to differentiate A. fumigatus strains; we observed a gr eat variety of strains among patients, a finding which is not in favor of a contamination from a unique source. However, nosocomial infectio n cannot be completly excluded since strains sharing same RAPD profile s were found in the environment and a few patients samples.