Fast and specific dermatophyte detection by automated DNA extraction and real-time PCR

Bergman, Antonina; Heimer, Dov; Kondori, Nahid; Enroth, Helena

doi:10.1111/1469-0691.12153

Cited by 37 publications

(44 citation statements)

References 28 publications

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“…In our settings, specific detection of T. rubrum in parallel with pan-dermatophyte primers is sufficient as the vast majority of positive samples were identified as T. rubrum [40 out of 44 (91 %) by culture, and 122 out of 132 (92.4 %) by the combination of culture and PCR]. Similar results were obtained in recent studies (Bergman et al, 2013;Verrier et al, 2012). Nevertheless, dermatophytes belonging to the less terbinafine-susceptible genus Microsporum are unanimously reported to be very rare agents of onychomycosis.…”

Section: Discussionsupporting

confidence: 87%

“…In our study, use of antifungals was an exclusion criterion and cannot explain the low sensitivity of culture. Nevertheless, PCR will detect non-viable cells with intact nucleic acid (Bergman et al, 2013). Finally, overgrowth of non-dermatophyte moulds in the culture medium may prevent or obscure development of a pathogen (Bontems et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

“…In a recent work, the primers adopted by the commercial PCR kit that is evaluated in the present study were used in two separate PCRs for the detection of pandermatophytes and specific detection of T. rubrum, supplemented with a third PCR for T. interdigitale (Dubljanin et al, 2014). However, real-time PCR is less laborious, may enable a broader spectrum of simultaneous species detection and as a closed system reduces contamination risk (Alexander et al, 2011;Bergman et al, 2013; Bergmans et al, 2010;Miyajima et al, 2013;Paugam et al, 2013;Wisselink et al, 2011). (Bergman et al, 2013;Verrier et al, 2012).…”

Section: Discussionmentioning

confidence: 99%

“…Negative PCR results despite a positive culture, although rare (6 cases, 1.4 % of nail samples), may be explained by an imbalanced distribution of fungal elements within different parts of a sample leading to an insufficient amount of DNA within the material used (Paugam et al, 2013). Alternatively, the presence of PCR-inhibitory substances may be involved (Bergman et al, 2013;Brasch et al, 2011;Mehlig et al, 2014). The presence of PCR-inhibitory substances is excluded in our study since internal control was positive in all cases.…”

mentioning

confidence: 90%

“…However, real-time PCR is less laborious, may enable a broader spectrum of simultaneous species detection and as a closed system reduces contamination risk (Alexander et al, 2011;Bergman et al, 2013; Bergmans et al, 2010;Miyajima et al, 2013;Paugam et al, 2013;Wisselink et al, 2011). (Bergman et al, 2013;Verrier et al, 2012). Nevertheless, dermatophytes belonging to the less terbinafine-susceptible genus Microsporum are unanimously reported to be very rare agents of onychomycosis.…”

mentioning

confidence: 99%

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Evaluation of a commercial PCR test for the diagnosis of dermatophyte nail infections

Spiliopoulou

Bartzavali

Jelastopulu

et al. 2015

Journal of Medical Microbiology

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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. INTRODUCTIONTinea refers to superficial infection of skin, hair and nails due to one of three fungal genera, Microsporum, Epidermophyton and Trichophyton, collectively known as dermatophytes (Clayton & Midgley, 1989;Hay, 1995;Moriarty et al., 2012). These associated infections are among the most common diseases worldwide and cause serious chronic morbidity. Tinea unguium, a dermatophyte infection of nails, also known as onychomycosis, has a prevalence of at least 12.4 % in the general population of Europe (Moriarty et al., 2012), whereas in older individuals it is as high as 50 % (Salgo et al., 2003). The disease is often atypical and aggressive in patients with untreated human immunodeficiency virus infection. Patients with psoriasis not only have an increased risk of onychomycosis but also require laboratory confirmation as the two conditions may be clinically similar (Moriarty et al., 2012). Trichophyton rubrum is the main pathogen implicated (Brillowska-Dabrowska et al., 2007;Tsoumani et al., 2011), followed by Trichophyton interdigitale, formerly Trichophyton mentagrophytes var. interdigitale (Cafarchia et al., 2013;Clayton & Midgley, 1989; Gräser et al., 1999;Nenoff et al., 2007). Less commonly associated species are Epidermophyton floccosum and Trichophyton verrucosum (Moriarty et al., 2012). In addition to dermatophytes, Candida and non-dermatophyte moulds may be recovered from clinically affected nails; however, their clinical significance is controversial (Brillowska-Dabrowska et al., 2007). Conventional diagnosis is based on detection of fungal elements by direct microscopy of clinical specimens, followed by culture and morphological identification of the fungus. The whole procedure is time-consuming, requiring 10 to 15 ...

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 90%

mentioning

confidence: 99%

See 3 more Smart Citations

Evaluation of a commercial PCR test for the diagnosis of dermatophyte nail infections

Spiliopoulou

Bartzavali

Jelastopulu

et al. 2015

Journal of Medical Microbiology

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Recent advances in the diagnosis of dermatophytosis

et al. 2020

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Dermatophytosis is a disease of global significance caused by pathogenic keratinolytic fungi called dermatophytes in both animals and humans. The recent taxonomy of dermatophytes classifies them into six pathogenic genera, namely Microsporum, Trichophyton, Epidermophyton, Nannizzia, Lophophyton and Arthroderma. It is because of the delayed diagnostic nature and low accuracy of dermatophyte detection by conventional methods that paved the path for the evolution of molecular diagnostic techniques, which provide the accurate and rapid diagnosis of dermatophytosis for an appropriate, timely antifungal therapy that prevents the nonspecific over‐the‐counter self‐medication. This review focuses on the importance of rapid and accurate diagnosis of dermatophytosis, limitations of conventional methods, selection of targets in diagnosis, and factors affecting sensitivity and specificity of various molecular diagnostic technologies in the diagnosis of dermatophytosis. Generally, all the molecular techniques have a significant edge over the conventional methods of culture and microscopy in the dermatophytosis diagnosis. However, in mycology laboratory, the suitability of any molecular diagnostic technique in the diagnosis of dermatophytosis is driven by the requirement of time, economy, complexity, the range of species spectrum detected and the scale of diagnostic output required. Thus, various choices involved in the pursuit of a diagnosis of dermatophytosis are determined by the available conditions and the facilities in the laboratory.

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The Potential of Molecular Diagnostics in Routine Dermatology

Kupsch

Gräser

2021

Dermatophytes and Dermatophytoses

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Fast and specific dermatophyte detection by automated DNA extraction and real-time PCR

Cited by 37 publications

References 28 publications

Evaluation of a commercial PCR test for the diagnosis of dermatophyte nail infections

Evaluation of a commercial PCR test for the diagnosis of dermatophyte nail infections

Recent advances in the diagnosis of dermatophytosis

The Potential of Molecular Diagnostics in Routine Dermatology

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