A multilocus sequence typing (MLST) scheme was devised for Aspergillus fumigatus. The system involved
sequencing seven gene fragments and was applied to a panel of 100 isolates of A. fumigatus from diverse
sources. Thirty different sequence types were found among the 100 isolates, and 93% of the isolates differed
from the other isolates by only one allele sequence, forming a single clonal cluster as indicated by the eBURST
algorithm. The discriminatory power of the MLST method was only 0.93. These results strongly indicate that
A. fumigatus is a species of a relatively recent origin, with low levels of sequence dissimilarity. Typing methods
based on variable numbers of tandem repeats offer higher levels of strain discrimination. Mating type data for
the 100 isolates showed that 71 isolates were type MAT1-2 and 29 isolates were MAT1-1
