title: Genetic diversity among clinical isolates of Acremonium strictum determined during an investigation of a fatal mycosis.
abstract: Primarily saprophytic in nature, fungi of the genus Acremonium are a well-documented cause of mycetoma and other focal diseases. More recently, a number of Acremonium spp. have been implicated in invasive infections in the setting of severe immunosuppression. During the course of routine microbiological studies involving a case of fatal mycosis in a nonmyeloablative hematopoietic stem cell transplant patient, we identified a greater-than-expected variation among strains previously identified as Acremonium strictum by clinical microbiologists. Using DNA sequence analysis of the ribosomal DNA intergenic transcribed spacer (ITS) regions and the D1-D2 variable domain of the 28S ribosomal DNA gene (28S), the case isolate and four other clinical isolates phenotypically identified as A. strictum were found to have <99% homology to the A. strictum type strain, CBS 346.70, at the ITS and 28S loci, while a sixth isolate phenotypically identified only as Acremonium sp. had >99% homology to the type strain at both loci. These results suggest that five out of the six clinical isolates belong to species other than A. strictum or that the A. strictum taxon is genetically diverse. Based upon these sequence data, the clinical isolates were placed into three genogroups.
authors.affiliation: Department of Laboratory Medicine, University of Washington, Fred Hutchinson Cancer Research Center, Seattle, Washington 98195, USA. novickit@u.washington.edu
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Novicki
authors.forename: Karen
authors.initials: K
authors.lastname: LaFe
authors.forename: Lynda
authors.initials: L
authors.lastname: Bui
authors.forename: Uyen
authors.initials: U
authors.lastname: Bui
authors.forename: Robert
authors.initials: R
authors.lastname: Geise
authors.forename: Kieren
authors.initials: K
authors.lastname: Marr
authors.forename: Brad T
authors.initials: BT
authors.lastname: Cookson
mesh_terms: D000164:Acremonium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D000935:Antifungal Agents / Q000494:pharmacology; D004275:DNA, Ribosomal / Q000032:analysis; D017809:Fatal Outcome; D014644:Genetic Variation; D005838:Genotype; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D009181:Mycoses / Q000382:microbiology*; D010641:Phenotype; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000935:Antifungal Agents; D004275:DNA, Ribosomal; D012339:RNA, Ribosomal, 28S