Discrimination of Scedosporium prolificans against Pseudallescheria boydii and Scedosporium apiospermum by semiautomated repetitive sequence-based PCR

Med Mycol. 2011 Jul;49(5):475-83. doi: 10.3109/13693786.2010.539630. Epub 2010 Nov 26.

Abstract

The laboratory identification of Pseudallescheria and Scedosporium isolates at the species level is important for clinical and epidemiological purposes. This study used semiautomated repetitive sequence-based polymerase chain reaction (rep-PCR) to identify Pseudallescheria/Scedosporium. Reference strains of Pseudallescheria boydii (n = 12), Scedosporium prolificans (n = 8), Scedosporium apiospermum (n = 9), and clinical/environmental isolates (P. boydii, 7; S. prolificans, 7; S. apiospermum, 7) were analyzed by rep-PCR. All clinical isolates were identified by morphological and phenotypic characteristics and by sequence analysis. Species identification of reference strains was based on the results of available databases. Rep-PCR studies were also conducted with various molds to differentiate Pseudallescheria/Scedosporium spp. from other commonly encountered filamentous fungi. All tested Pseudallescheria/Scedosporium isolates were distinguishable from the other filamentous fungi. All Scedosporium prolificans strains clustered within the cutoff of 85%, and species identification by rep-PCR showed an agreement of 100% with sequence analysis. However, several isolates of P. boydii and S. apiospermum did not cluster within the 85% cutoff with the same species by rep-PCR. Although the identification of P. boydii and S. apiospermum was not correct, the semiautomated rep-PCR system is a promising tool for the identification of S. prolificans isolates.

Publication types

  • Evaluation Study

MeSH terms

  • Automation / methods
  • Humans
  • Microscopy
  • Molecular Diagnostic Techniques / methods*
  • Mycological Typing Techniques
  • Mycology / methods*
  • Polymerase Chain Reaction / methods*
  • Pseudallescheria / classification*
  • Pseudallescheria / genetics
  • Pseudallescheria / isolation & purification*
  • Pseudallescheria / physiology
  • Repetitive Sequences, Nucleic Acid
  • Scedosporium / classification*
  • Scedosporium / genetics
  • Scedosporium / isolation & purification*
  • Scedosporium / physiology
  • Sensitivity and Specificity