Genetic diversity among clinical isolates of Acremonium strictum determined during an investigation of a fatal mycosis.
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.
Novicki
Thomas J
TJ
Department of Laboratory Medicine, University of Washington, Fred Hutchinson Cancer Research Center, Seattle, Washington 98195, USA. novickit@u.washington.edu
LaFe
Karen
K
Bui
Lynda
L
Bui
Uyen
U
Geise
Robert
R
Marr
Kieren
K
Cookson
Brad T
BT
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
D000935:Antifungal Agents; D004275:DNA, Ribosomal; D012339:RNA, Ribosomal, 28S