Comparison of Two Highly Discriminatory Molecular Fingerprinting Assays for Analysis of Multiple Aspergillus fumigatus Isolates from Patients with Invasive Aspergillosis

Two highly discriminatory fingerprinting assays, short tandem repeat typing and amplified fragment length polymorphism (AFLP), were compared to determine the genetic relatedness between 55 isolates of Aspergillus fumigatus obtained from 15 different patients suffering from proven invasive aspergillosis. Both techniques showed that interpatient isolates belonged to different genotypes and that intrapatient isolates from deep sites were all of the same genotype. By contrast, multiple genotypes were found among isolates originating from respiratory samples. Both techniques have specific advantages and disadvantages. AFLP is more universally applicable, but short tandem repeat analysis offers better discriminatory power and should be the preferred method for standardizing typing of clinical isolates of Aspergillus fumigatus. Invasive aspergillosis (IA) is a life-threatening disease of patients who are immunocompromised by hematopoietic stem cell or solid organ transplantation, intensive chemotherapy, or treatment with corticosteroids (11). Aspergillus fumigatus is most frequently involved in causing this life-threatening dis-ease. IA is a growing problem in hospitals because of the inexorable rise in the number of severely immunocompro