Molecular typing of Aspergillus species

Abstract

Aspergillus species are widely distributed fungi that release large amounts of airborne conidia, which are dispersed in the environment. Several Aspergillus species have been described as human pathogens. Molecular techniques have been developed to investigate the epidemiological relation between environmental and clinical isolates. Several typing methods have been described for Aspergillus species, most of them with reference to Aspergillus fumigatus. Here, we summarise all the different available molecular typing techniques for Aspergillus. The performance of these techniques is evaluated with respect to their practical feasibility, and their interpretation and discriminatory power assessed. For A. fumigatus isolates, a large extent of genetic variability is demonstrated and therefore fingerprinting techniques with high discriminatory power and high reproducibility are required for this species. Afut1-restriction fragment length polymorphism and microsatellite typing showed the highest discriminatory power. In addition, the microsatellites show excellent reproducibility. Other typing techniques are still useful for smaller epidemiological problems and for less well-equipped laboratories.

Diversity of clinical isolates of Aspergillus terreus in antifungal susceptibilities, genotypes and virulence in Galleria mellonella model: Comparison between respiratory and ear isolates

“…terreus species has been demonstrated by genotyping methods, such as random amplified polymorphic DNA, repetitive-sequence-based polymerase chain reaction (PCR), inter-simple sequence repeat PCR, and multilocus sequencing typing [19]. However, these techniques have poor inter-laboratory reproducibility and do not allow for the exchange of results between laboratories [19]. Instead, microsatellite-based typing, also referred to as short tandem repeat (STR)-based typing, has been introduced for genotyping of Aspergillus species and could yield a precise numerical result.…”

Isolate-Dependent Growth, Virulence, and Cell Wall Composition in the Human Pathogen Aspergillus fumigatus

“…Studies that attempt to identify virulence factors of A. fumigatus may be confounded by the extensive genetic and phenotypic variability observed between fungal isolates [5]. Sampling of health care centers reported a large diversity among clinical and environmental isolates in patients and in areas associated with patient care; in some instances changes in the environmental isolates that were sampled were seen over several months at the same location [6]–[11].…”

Microsatellite typing of avian clinical and environmental isolates ofAspergillus fumigatus

“…While the discriminatory power is high in patternbased techniques, such as random amplified polymorphic DNA analysis, restriction fragment length polymorphism analysis, and amplified fragment length polymorphism, STRAf typing proved to be more simple and reproducible (Bart-Delabesse et al, 1998;de Valk et al, 2005de Valk et al, , 2007aVanhee et al, 2008aVanhee et al, , 2008b. However, any typing method is associated with its specific advantages and disadvantages (de Valk et al, 2007b) and any technical complications associated with microsatellite typing (Pasqualotto et al, 2007;Alvarez-Perez et al, 2009) can be properly addressed Klaassen, 2010).…”