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Background: Dermatophytes are group of fungi that cause superficial infections via enzymes that degrade keratin in human skin. Several factors, including climate, gender, age, lifestyle, human migration, cultural habits, and socioeconomic status influence the prevalence of dermatophyte infections. We analyzed the prevalence of dermatophyte isolates in a hospital in Eastern Saudi Arabia from 2000 to 2019. Methods: The data on fungal cultures were obtained from the Laboratory Information System of the Mycology Laboratories at Johns Hopkins Aramco Healthcare, and were used for the analysis. Fungal isolates were examined microscopically for the presence of specialized hyphal structures and conidia. The Vitek® MS microbial identification system (biomerieux) was used if the culture type was not identified microscopically. Results: Among the 10,021 samples analyzed, 3040 (30.33%) were positive for fungi and only 398 (3.97%) were dermatophytes. Microsporum species was the most common dermatophyte accounting for 50.5% (n = 201) followed by trichophyton with 36.9% (n = 147). The most common positive samples were scrapping (251, 63%) and hair (68, 17%). Culture positivity relative to the age groups revealed a cluster of positive dermatophyte species in children < 10 years of age with 215 (54%) of all cases and among 10–19 years of age with 60 (15) of the cases (p < 0.001). Microsporum species were the prevalent dermatophytes in patients < 10 years of age, while Epidermophyton species were the most frequent dermatophyte species in age groups 10–19, 20–29, and 30–39 years. However, Trichophyton species were the most frequent dermatophyte species in individuals 70–79 years. The percentage of Microsporum and Trichophyton species decreased significantly over time (p < 0.001). In addition, there was a significant seasonal variation in relation to Trichophyton species. A comparison between the most frequent species showed that there was no difference in relation to gender, but there was a difference in relation to the specimen type and age group. Conclusion: Dermatophytosis was common among children and adolescent with the most common samples were scrapping and hair. There was a significant reduction in Microsporum and Trichophyton species over time. [ABSTRACT FROM AUTHOR]

Recent taxonomical revisions based on multilocus gene sequencing have provided some clarifications to dermatophyte (Arthrodermataceae) family tree. These changes promoted us to investigate the impact of the changed nomenclature of the dermatophyte strains in the BCCM/IHEM fungal collection, which contains strains of all dermatophyte genera except for Ctenomyces. For 688 strains from this collection, both internal transcribed spacer region (ITS) and partial β-tubulin (BT) sequences were aligned and a multilocus phylogenetic tree was constructed. The ITS + BT phylogentic tree was able to distinguish the genera Arthroderma, Lophophyton, Microsporum, Paraphyton, Nannizzia and Trichophyton with high certainty. Epidermophyton, which is widely considered as a well-defined genus with E. floccosum as the only representative, fell within the Nannizzia clade, whereas the phylogenetic analysis, based on the ITS region alone, differentiates Epidermophyton from Nannizzia as a separate genus. Re-identification and reclassification of many strains in the collection have had a profound impact on the composition of the BCCM/IHEM dermatophyte collection. The biggest change is the decline of prevalence of Arthroderma strains; starting with 103 strains, only 22 strains remain in the genus after reassessment. Most Arthroderma strains were reclassified into Trichophyton, with A. benhamiae and A. vanbreuseghemii leaving the genus. The amount of Microsporum strains also dropped significantly with most of these strains being reclassified into the genera Paraphyton and Nannizzia. [ABSTRACT FROM AUTHOR]

With regard to increasing number of antifungal-resistant dermatophytes, antifungal susceptibility testing of dermatophytes serves as a useful tool in managing clinical dermatophytosis. This study aimed to determine antifungal susceptibility profile of clinically important dermatophytes and determination of point mutations in terbinafine-resistant isolates. Based on our results, dermatophytosis was confirmed in 97 cases by direct microscopic examination, culture, and sequencing of ITS region. Antifungal susceptibility of 97 dermatophyte isolates distributed in four species including Trichophyton interdigitale (26 isolates), T. rubrum (19 isolates), T. tonsurans (29 isolates), and Epidermophyton floccosum (21 isolates) was assessed to nine antifungal agents using CLSI M38-A2 guidelines. Minimum inhibitory concentration range (MIC range) for luliconazole and terbinafine was 0.001-0.008 μg/ml and 0.003-> 32 μg/ml, compared to 0.03-64 μg/ml for griseofulvin, 0.01-16 μg/ml for itraconazole and voriconazole, 0.03-8 μg/ml for ketoconazole, 0.03-32 μg/ml for econazole, 0.03-1 μg/ml for lanoconazole, and 0.01-4 μg/ml for butenafine. Trichophyton tonsurans was the most susceptible (MIC = 0.006 μg/ml) and E. floccosum was the most resistant (MIC = 0.02 μg/ml) species to terbinafine. Terbinafine resistance was reported for two species, i.e., T. rubrum and T. tonsurans at the total rate of 2% which was due to Leu393Phe substitution in both species. Taken together, our results assist clinicians and prompt the current knowledge about the necessity of antifungal susceptibility testing to select effective strategies for management of clinical cases of dermatophytosis. [ABSTRACT FROM AUTHOR]

MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry (MS) is a new tool for the identification of microorganisms, inclusive of dermatophytes. The technique is faster, more straightforward, and powerful when compared to conventional dermatophyte identification methods (culture and microscopy). Accurate species identification in dermatophytes is not only essential to survey epidemiologic situations, but also for an appropriate medical treatment and to locate the source of infection (zoophilic or anthropophilic). Multiple platforms from a number of well-established commercial manufacturers (Andromas SAS, Bruker Daltonics, bioMérieux) have been used for dermatophyte identification with different success. Independent from the platform used, all of the studies reviewed here report on problems with the identification of phylogenetically closely related anthropophilic and zoophilic dermatophyte species. Thus, supplementation of the databases/libraries as well as standardized extraction protocols and cultivation methods are the precondition required for optimal species identification. [ABSTRACT FROM AUTHOR]

Dermatophytoses are considered to be one of the major public health problems in the world and are among the most commonly diagnosed skin diseases in Iran. In spite of improved personal hygiene and living environment, dermatophytosis continues to spread and persist. To determine the prevalence of dermatophytosis and their etiologic agents in Mashhad (Iran), five hundred and sixty patients suspected to have fungal infection were studied. Subjects who participated in this study were 330 males and 230 females ranged in age from 4 months to 70 years with a mean age of about 25.5 years. Clinical materials including skin scraping, hair and scalp sample, nail clipping and subungual debris were collected. All of the specimens were assessed by direct examination and culture. Of 560 patients, 166 (29.6 %) had dermatophytosis. The types of tinea according to anatomical areas were as follows: tinea corporis (33.1 %), tinea capitis (32.5 %), tinea manuum (17.5 %), tinea cruris (10.2 %), tinea pedis (5.4 %), tinea unguium (0.6 %) and tinea barbae (0.6 %). Trichophyton verrucosum was the most prevalent species followed by Trichophyton violaceum and Trichophyton mentagrophytes. The prevalence of dermatophytosis in males was higher than in females. Based on a review of published studies from different parts of Iran, there are regional differences in the incidence of dermatophytosis. Epidermophyton floccosum has been the most prevalent species, and Microsporum canis has been isolated less than from the other countries. [ABSTRACT FROM AUTHOR]

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A new series of 5-arylhydrazonothiazole derivatives 5a–d has been synthesized, elucidated, and evaluated for their antidermatophytic activity. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the newly synthesized products were investigated against 18 dermatophyte fungal isolates related to Epidermophyton floccosum, Microsporum canis, and Trichophyton rubrum. The morphological alterations induced by the synthesized derivatives singly or conjugated with the monoclonal antibody were examined on spores of T. rubrum using a scanning electron microscope. The efficacy of synthesized derivative 5a applied at its respective MFC alone or conjugated with anti-dermatophyte monoclonal antibody 0014 in skin infection treatment of guinea pigs due to inoculation with one of the examined dermatophytes, in comparison with fluconazole as standard reference drug was evaluated. In an in vivo experiment, the efficiency of 5a derivative conjugated with the antibody induced 100% healing after 45 days in the case of T. rubrum and M. canis-infected guinea pigs. [ABSTRACT FROM AUTHOR]