Fungal Genet Biol 2008, 45:165–70.PubMedCrossRef 24. Thompson JD, Higgins DG, Gibson TJ: CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. Nucleic acids research 1994, 22:4673–80.PubMedCrossRef 25. Saitou N, Nei M: The neighbor-joining method: a new method for reconstructing phylogenetic trees. Molecular biology and evolution 1987, 4:406–25.PubMed Authors’ contributions KRP, UHM, BGH and TBR conceived the study. BGH designed the experiments. BGH, HJG, CSK and JBN carried out the research. JCF contributed to the design of experiments

and provided expertise in mycology. BGH and HJG prepared the first draft

of the manuscript. UHM and KRP contributed to the experimental design and preparation of the manuscript. All authors were involved in the revision of the draft manuscript selleck chemical and have Q-VD-Oph nmr agreed to the final content.”
“Background Aspergillus species are believed to be cosmopolitan organisms, existing as unstructured global populations. Species belonging to this taxon, including A. fumigatus, A. terreus, A. flavus and others, cause invasive aspergillosis (IA) predominantly in severely immunocompromised individuals. The majority of studies with A. fumigatus have demonstrated no association between find more genotypes and geography. Several studies employing comparative sequence analysis of different loci, including protein coding, intergenic and microsatellite containing regions, arrived at the conclusion that there was no correlation between genotype

and geographical origin among A. fumigatus isolates [1–3]. In contrast to these observations, one study demonstrated the presence of multiple, well-supported phylogenetic clusters amongst A. fumigatus isolates from a collection of isolates geographically dispersed across North America [4]. The locus sequenced was a single gene encoding a putative cell surface protein, Afu3g08990 (CSP), in which polymorphisms consisted of insertions and deletions within a repeat region. The authors speculated that the presence of clusters may have been undetected previously due to the reliance why on data from loci lacking sufficient polymorphisms. Aspergillus terreus is the second or third most common etiological agent of IA and interestingly, appears to be the most common cause of infection in some medical centers, suggesting ecological specificity for this organism [5–7]. Previous efforts to determine population structure in A. terreus have been hampered by the lack of reliable methods for exploiting genetic variability to distinguish or group isolates. Balajee et al., employing a multi-gene sequencing approach to a large global collection of isolates previously identified as A. terreus, showed that no evidence of endemism existed but were able to define a genotypically distinct species, A. alabamensis [8].