MYCOSES MYCOSES 44, 351±355 (2001) A CCEPTED CCEPTED:D ECEMBER ECEMBER 13, 2000 C ONGRESS ONGRESS R EPORT EPORT Aspergillus fumigatus ± virulence and opportunism? Aspergillus fumigatus ± Virulenz und Opportunismus? M. Weig, U. Reichard and U. Groû Key words. Aspergillus fumigatus, virulence, opportunism. Schlu È sselwo È rter. Aspergillus fumigatus, Virulenz, Opportunismus. The Interdisciplinary Forum on Aspergillosis, organized by the Deutsche Gesellschaft fu Èr Hygiene und Mikrobiologie (DGHM) section, Eucaryotic Pathogens, and the Deutschsprachige Mykologische Gesellschaft (DmykG), was held at the Georg-August-University of Go Èttingen, Germany, 7±8 April 2000. Introduction Aspergillus fumigatus is frequently found in the environment. Increasing numbers of patients with therapeutically induced immunosuppression, leukopenia or chronic granulomatous disease are becoming susceptible to invasive infection with A. fumigatus. As diagnosis might be dif®cult and thus be delayed, a fatal outcome of invasive aspergillosis is frequently observed. This situa- tion has promoted intensive research into the pathogenesis of aspergillosis, and the aim of the Interdisciplinary Forum on Aspergillosis was to stimulate further interactions between clinicians and basic scientists. Relationship between genotypes and disease? Conidia of A. fumigatus are frequently inhaled by humans. However, only a small proportion of the exposed individuals develop a clinical mani- festation of disease. Most of the susceptible patients suffer from immunosuppression and may present with invasive pulmonary or disseminated aspergillosis. Immunocompetent patients with pre-existing pulmonary cavity are at risk for aspergilloma. In addition to these, another group of patients respond with a hyperergic immune reaction resulting in type III allergy to A. fumigatus. The European group for research on biotypes and genotypes of Aspergillus (EBGA) under the co- ordination of Rene Âe Grillot (Ho Ãpital Michallon, Grenoble, France) has investigated the relation- ship between genotypes of A. fumigatus and mani- festation of invasive aspergillosis. From strains obtained from the EBGA culture collection (44 isolates of eight patients from Lyon, France) the genetic polymorphism of A. fumigatus in lung transplant recipients (LTR) was analysed by a combination of DNA-based and protein-based methods (random ampli®ed polymorphic DNA (RAPD), sequence-speci®c DNA primer analysis (SSDP) and multilocus enzyme electrophoresis (MLEE)). In this series, the majority of specimens contained only one genotype, indicating that co-infection with two different genotypes is a rare event. Follow-up investigations of LTR were performed for a period of 7 days to more than 3 years. Sixteen different genotypes were identi- ®ed. A wide variability of genetic polymorphism was observed between sequential isolates in most of these patients. However, some individuals (two of eight) showed persistence of a unique geno- type for the entire duration of the follow-up. Most noteworthy, no correlation between geno- types and the type of Aspergillus disease was Correspondence: Dr U. Reichard, Abteilung Bakteriologie, Kreuzbergring 57, D-37075 Go Èttingen, Germany. Tel: + 49-551-395801 Fax: + 49-551-395856 E-mail: utzreichard@yahoo.com Department of Bacteriology, Georg-August-University, Go Èttingen, Germany.