Utility of a microsatellite assay for identifying clonally related outbreak isolates of Aspergillus fumigatus.

A microsatellite assay based on short tandem repeats (STRAf) has been recently described as a discriminatory, high throughput assay for fingerprinting Aspergillus fumigatus isolates. However, the STRAf assay has not been tested for its utility in outbreak settings where it is critical to distinguish clonal clusters from genetically unrelated genotypes. In the present study, employing a panel of epidemiologically linked A. fumigatus isolates obtained from 6 different outbreaks of invasive aspergillosis (IA), we demonstrate that the STRAf assay can be a valuable molecular tool to support epidemiological investigations. We also report for the first time the detection of microvariation events in the A. fumigatus population studied.