title: Clinical application of a molecular assay for the detection of dermatophytosis and a novel non-invasive sampling technique.
abstract: The dermatophytoses are the most common superficial fungal infections worldwide. Clinical diagnosis is not reliable as there are many differentials, and laboratory diagnosis is required to gain access to treatment in more severe disease. Traditional diagnostic methods are limited by suboptimal sensitivity, specificity and prolonged turnaround times. Molecular methods are being used increasingly in the diagnostic algorithm in the clinical microbiology laboratory. The aim of this study was to evaluate a real-time polymerase chain reaction (RT-PCR) targeting the chitin synthase 1 gene (CHS1) of dermatophytes for analytical specificity, and to assess its clinical application by comparing it to the current methods of microscopy and culture. We also assessed a novel non-invasive sample collection technique involving adhesive tape impressions of suspected lesions. The PCR was highly specific, being able to discern between cultures of dermatophytes and other microorganisms. It also proved to be more sensitive than traditional methods at detecting dermatophytes in clinical samples. Similar sensitivities were seen on the samples assessed by the adhesive tape technique. An internal control system allowed for the detection of inhibition in certain culture and clinical specimens. This rapid and cost-effective technique could be incorporated into the initial diagnostic algorithm for dermatophytosis in Australian laboratories.
authors: Department of Microbiology, South Eastern Area Laboratory Services, St George Hospital, Sydney, Australia. Electronic address: alice_kg@hotmail.com.
authors: Alice
authors: A
authors: Kizny Gordon
authors: Department of Microbiology, South Eastern Area Laboratory Services, St George Hospital, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney, Australia.
authors: Christopher
authors: C
authors: McIver
authors: Faculty of Medicine, University of New South Wales, Sydney, Australia; Department of Dermatology, St George Hospital, Sydney, NSW, Australia.
authors: Minhee
authors: M
authors: Kim
authors: Faculty of Medicine, University of New South Wales, Sydney, Australia; Department of Dermatology, St George Hospital, Sydney, NSW, Australia.
authors: Dedee F
authors: DF
authors: Murrell
authors: Department of Microbiology, South Eastern Area Laboratory Services, St George Hospital, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney, Australia.
authors: Peter
authors: P
authors: Taylor
mesh_terms: D005656:Fungal Proteins / Q000032:analysis; D006801:Humans; D008828:Microbiological Techniques; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014005:Tinea / Q000175:diagnosis*
chemical_list: D005656:Fungal Proteins
keywords: Adhesive tape; chitin synthase; dermatophytes; real-time polymerase chain reaction; tinea