Identification of rare macroconidia-producing dermatophytic fungi by real-time PCR.

To understand the pathogenicity and clinical significance of dermatophytes (also known as ringworms), the correct identification of these molds is essential. However, in routine practice they are notoriously difficult to classify and identify. The morphology of macroconidia, which are abundantly produced under suitable in vitro conditions, have provided useful criteria for the identification of many of the dermatophytes. However, several of them, including Microsporum audouinii, M. ferrugineum, Trichophyton concentricum, T. schoenleinii, T. verrucosum, and T. violaceum (including T. soudanense and T. yaoundei) rarely produce macroconidia and cannot be easily identified. The objective of this study was to design, optimize, and evaluate real-time PCR as a tool for identifying dermatophytic fungi in a laboratory setting. The performance of the assay was evaluated using 64 dermatophyte isolates, i.e., 35 rare macroconidia-producing reference strains, including the six species mentioned above, and 29 clinical isolates from our laboratory, including M. canis (4), T. mentagrophytes (2), T. rubrum (20), T. rubrum with the 'raubitschekii' morphotype (2), and T. tonsurans (1). Real-time PCR correctly identified 10 taxonomically distinct dermatophytes, particularly rare macroconidia-producing species, with excellent sensitivity (100%). The advantages of the assay include the provision of accurate and reliable diagnoses of dermatophytic fungi.

Trichophyton Rubrum with the 'raubitschekii' morphotype: the first report from Turkey.

In modern taxonomy, Trichophyton rubrum with the 'raubitschekii' morphotype differs from the common strains of T. rubrum morphologically, physiologically, and clinically, despite genetic homogeneity. In this paper, we report the first autochthonous Turkish cases in a 24-year-old woman and her 26-year-old fiancé with tinea cruris and tinea manuum, respectively. The isolates were proven to be T. rubrum with the 'raubitschekii' morphotype by their morphological and physiological characteristics including the following: (1) granular colony surface, (2) profuse macroconidia and microconidia, (3) strongly positive urease activity after 3 days, (4) non-perforating hair, (5) restricted growth and producing no alkaline reaction on bromocresol purple-milk solids-glucose agar, and (6) restricted growth and producing no conidia on 3-9% NaCl-supplemented Sabouraud agar. The internal transcribed spacer (ITS) regions of both isolates were sequenced, and the assembled DNA sequences were examined using the Basic BLAST (nucleotide-nucleotide) software of the National Center for Biotechnology Information web database. Actually, the lack of epidemiological data on this variety is notable, and the actual prevalence is unknown. Otherwise, routine methods misidentified the strains as T. rubrum or unrecognized cases were underreported.

[A tinea incognito case caused by Trichophyton rubrum with clinical and mycological cure and review of the literature]. / Trichophyton rubrum'un etken oldugu, klinik ve mikolojik iyilesme saptanan bir tinea incognito olgusu ve literatür derlemesi.

Tinea incognito is the result of lack of diagnosis of dermatophyte infection of the glabrous skin and the misuse of steroids or calcineurin inhibitors. In this case report a 20-years-old female patient diagnosed as tinea incognito and Trichophyton rubrum isolated from her skin lesions, was presented. The patient suffered from an itchy skin lesion on her neck and right breast. Physical examination revealed and plaques with erythema and papules on neck and breast area. The patient had used several corticostero- ids suggested by dermatologists for 10 months. Direct microscopic examination of the skin scrapings with 10% potassium hydroxide preparation revealed fungal elements and Trichophyton rubrum was isolated in culture. Use of corticosteroids was ceased and terbinafine (250 mg tb and cream) therapy was initiated to continue for four weeks. Following treatment, total clinical and mycological cure was established. It was concluded that tinea incognito which was not a rare clinical entity, could be presented in various clinical forms and usually resulted from the wrong treatment modalities. Thus atypical erythematous plaques should be investigated in terms of presence of fungi and treated accordingly to establish total clinical and mycological cure.

Clonal outbreak of Trichophyton tonsurans tinea capitis gladiatorum among wrestlers in Adana, Turkey.

Tinea capitis gladiatorum and tinea corporis gladiatorum caused by the anthropophilic dermatophyte Trichophyton tonsurans are well-known clinical entities in individuals involved in combat sports, e.g., wrestlers and judo practitioners. We present an outbreak of Trichophyton tonsurans tinea capitis gladiatorum among wrestlers at a boarding school in Adana, Turkey. Fourteen of the 29 wrestlers examined (48.3%) harbored the pathogen, including eight asymptomatic scalp carriers, five with tinea capitis superficialis, and one asymptomatic trunk carrier. Dermatophytes were isolated from samples of the neck (1), nape (1), trunk (3) and inguinal area (2) in four of the five tinea capitis cases. A total of five inanimate objects, i.e., two wrestling mats, two pillowcases, and one sheet were also found to be positive for T. tonsurans. Mixed-marker strain typing examining 24 sequence variations in 12 gene loci confirmed that the outbreak was caused by a single strain of T. tonsurans.