title: Evaluation of a commercial PCR test for the diagnosis of dermatophyte nail infections.
abstract: Tinea unguium, known as onychomycosis, is a dermatophyte infection of nails with worldwide distribution. Conventional methods for detecting fungi in nail specimens are either non-specific (microscopy) or insensitive (culture). PCR has been used to improve sensitivity in detecting the causative fungi in nail specimens from patients with suspected onychomycosis. Results of a commercial multiplex PCR for the detection of dermatophytes, especially Trichophyton rubrum (the main dermatophyte implicated), as compared to conventional methods are presented. A total of 418 nail scrapings obtained from dermatological outpatients were handled in the Laboratory of Microbiology between May 2010 and May 2013. Among them, multiplex PCR detected 126 (30.1 %) dermatophyte-positive samples, whereas culture revealed 44 (10.5 %). Direct microscopy revealed 63 (15.1 %) positive specimens. T. rubrum was identified in 116 out of 126 (92 %) positive PCR samples and 40 out of 44 (91 %) dermatophyte-positive cultures. Implementation of PCR increased species-specific detection of dermatophytes by 21.1 %, leading to a threefold increase as compared to culture alone. Multiplex PCR offers a time-saving diagnostic tool for tinea unguium and augments laboratory assistance to clinical evaluation for proper treatment.
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, 26500 Patras, Greece.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Spiliopoulou
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, 26500 Patras, Greece.
authors.forename: Christina
authors.initials: C
authors.lastname: Bartzavali
authors.affiliation: Department of Hygiene, School of Medicine, University of Patras, 26500 Patras, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Jelastopulu
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, 26500 Patras, Greece.
authors.forename: Evangelos D
authors.initials: ED
authors.lastname: Anastassiou
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, 26500 Patras, Greece.
authors.forename: Myrto
authors.initials: M
authors.lastname: Christofidou
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003883:Arthrodermataceae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005260:Female; D006801:Humans; D008297:Male; D008828:Microbiological Techniques / Q000379:methods*; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D009172:Mycology / Q000379:methods; D014009:Onychomycosis / Q000175:diagnosis* / Q000382:microbiology*; D012680:Sensitivity and Specificity