Discrimination of Scedosporium prolificans against Pseudallescheria boydii and Scedosporium apiospermum by semiautomated repetitive sequence-based PCR.
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.
Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany. Joerg.Steinmann@uk-essen.de
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J
Steinmann
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Schmidt
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J
Buer
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PM
Rath
D001331:Automation / Q000379:methods; D006801:Humans; D008853:Microscopy; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016533:Mycological Typing Techniques; D009172:Mycology / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011541:Pseudallescheria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D012091:Repetitive Sequences, Nucleic Acid; D021681:Scedosporium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D012680:Sensitivity and Specificity