Molecular typing of Aspergillus terreus isolates by random amplification of polymorphic DNA

Forty three isolates of Aspergillus terreus of environmental or clinical or igin were typed by random amplification of polymorphic DNA (RAPD) with two different primers NS3 and NS7 from the fungal ribosomal 18S subunit gene. F ur the 31 epidemiologically unrelated isolates tested, the primers NS3 and NS7 gave rise to 23 and 24 different genotypes, respectively, and combining the: results obtained with the two primers allowed the differentiation of all these isolates. No clustering was found in relation to pathogenicity cl inical signs, or geographic origin of the isolates. Five groups of related isolates of A. terreus were also typed. Analysis of sequential isolates fro m patients with cystic fibrosis or with invasive aspergillosis showed the c lonality of the colonization or infection by ii. terreus. Likewise, this st raightforward typing method demonstrated the clonal origin of a massive con tamination of the environment in a haematology unit. Therefore this RAPD ty ping method may constitute a valuable tool for the epidemiological follow-u p of airway colonization in patients with cystic fibrosis or investigations of links between nosocomial outbreaks of invasive aspergillosis and enviro nmental contamination. (C) 2000 The Hospital infection Society.