Identification of Trichophyton mentagrophytes strains isolated from patients with dermatophytosis (original) (raw)
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Molecular identification of isolates of the Trichophyton mentagrophytes complex
International Journal of Medical Sciences, 2020
Background: The Trichophyton mentagrophytes complex is the second most common causal agent of dermatophytosis. It comprises five species-T. mentagrophytes, T. interdigitale, T. erinacei, T quinckeanum, and T. benhamie, as well as nine different genotypes of T. mentagrophytes / T. interdigitale-which are morphologically similar; however, their susceptibility to antifungal agents may differ. For targeted therapy and better prognosis, it is important to identify these species at a molecular level. However, since many hospitals lack molecular methods, the actual aetiology of dermatophytosis caused by this complex remains unknown. Objective: To characterize 55 anthropophilic isolates of the T. mentagrophytes complex recovered from a dermatological centre in Yucatán, Mexico. Material and methods: Fifty-five isolates of the T. mentagrophytes complex were obtained from patients with tinea capitis, tinea pedis, tinea corporis, tinea barbae, and tinea unguium. They were characterized by their colonial and microscopic morphology on Sabouraud dextrose agar (SDA) and through the sequencing of a fragment from the region ITS1-5.8S-ITS2. Results: All colonies grown on SDA were white. Forty-six isolates formed colonies with a powdery texture, while nine isolates formed colonies with a velvety texture. The micromorphological features were typical of the T. mentagrophytes complex. The molecular analysis revealed that 55 isolates were microorganisms that belonged to the T. mentagrophytes complex, that 46 formed powdery colonies representing T. mentagrophytes, and that the other nine isolates that formed velvety colonies represented T. interdigitale. The latter nine isolates were obtained from patients with tinea pedis, tinea corporis, and tinea unguium. Conclusions: The colony morphology on SDA led to the identification of 46 isolates as T. mentagrophytes and nine isolates as T. interdigitale. At a molecular level, the species identified by their morphology were identified only as T. mentagrophytes complex.
Medical Mycology
This study looked for correlations between molecular identification, clinical manifestation, and morphology for Trichophyton interdigitale and Trichophyton mentagrophytes. For this purpose, a total of 110 isolates were obtained from Czech patients with various clinical manifestations of dermatophytosis. Phenotypic characters were analyzed, and the strains were characterized using multilocus sequence typing. Among the 12 measured/scored phenotypic features, statistically significant differences were found only in growth rates at 37 °C and in the production of spiral hyphae, but none of these features is diagnostic. Correlations were found between T. interdigitale and higher age of patients and between clinical manifestations such as tinea pedis or onychomychosis. The MLST approach showed that internal transcribed spacer (ITS) genotyping of T. mentagrophytes isolates has limited practical benefits because of extensive gene flow between sublineages. Based on our results and previous st...
Trichophyton mentagrophytes ITS Genotype VII from Thailand
Dermatophytes and Dermatophytoses, 2021
The question arises if the isolates of T. mentagrophytes genotype VII recently detected in Europe, especially in Germany, do possess higher virulence when compared to other genotypes of T. mentagrophytes. Laboratory investigations on pathogenicity and virulence factors of this dermatophyte should be initiated to answer to this speculation. 6
Armaghane Danesh Bimonthly Journal, 2008
Trichophyton rubrum represents the most frequently isolated causative agent of superficial dermatophyte infections. Several genotyping methods have recently been introduced to improve the delineation between pathogenic fungi, both at the species and strain level. The purpose of this study was to apply selected DNA fingerprinting methods to the identification and strain discrimination of T. rubrum clinical isolates. Fifty-seven isolates from as many tinea patients were subjected to species identification by PCR-restriction fragment length polymorphism (RFLP) analysis and strain differentiation using a randomly amplified polymorphic DNA (RAPD) method, with two primers designated 1 and 6. Using PCR-RFLP, 55 of the isolates studied were confirmed to be T. rubrum. Among those, a total of 40 and 5 distinct profiles were obtained by RAPD with primer 1 and 6, respectively. The combination of profiles from both RAPD assays resulted in 47 genotypes and an overall genotypic diversity rate of 85.4%. A dendrogram analysis performed on the profiles generated by RAPD with primer 1, showed most of the isolates (87.3%) to be genetically related. The PCR-RFLP serves as a rapid and reliable method for the identification of T. rubrum species, while the RAPD analysis is rather a disadvantageous tool for T. rubrum strain typing.
Mycoses, 2019
Background: The fungi Trichophyton mentagrophytes and T. interdigitale account for significant amount of dermatophytosis cases worldwide. These two dermatophytes form a species complex and have a number of ribosomal ITS region genotypes, allowing simultaneous species identification and strain typing. Objectives: Our aim was to describe the geographic distribution of T. mentagrophytes / T. interdigitale ITS region genotypes and find an association between the genotypes and clinical presentations of respective infections. Patients/Methods: We performed rDNA ITS region sequencing in 397 Iranian T. mentagrophytes / T. interdigitale isolates and analyzed all available in GenBank entries with sequences of this kind. For the study, 515 clinical annotations were available. Statistical analysis was performed by chi-squared test and Spearman rank correlation analysis. Results: A total of 971 sequences belonged to genotypes with at least 10 geographic annotations and were classified on the basis of exclusive occurrence in a particular region or high relative contribution to a regional sample. We discerned Asian and Oceanian ("KU496915" Type V, "KT192500" Type VIII, "KU315316"), European ("FM986750" Type III, "MF926358" Type III*, "KT285210" Type VI) and cosmopolitan ("FM986691" Type I, "JX122216" Type II, "KP132819" Type II* and "AF170453" Type XXIV) genotypes. There was statistically significant difference in the ITS genotype distribution between different affected body sites. Trichophyton mentagrophytes "KT192500" Type VIII correlated with Accepted Article This article is protected by copyright. All rights reserved. tinea cruris, T. mentagrophytes "KU496915" Type V correlated with tinea corporis, T. interdigitale "JX122216" Type II correlated with tinea pedis and onychomycosis. Conclusion: Trichophyton mentagrophytes and T. interdigitale genotypes can be associated with distinct geographic locations and particular clinical presentations.
Journal of Clinical Microbiology, 1988
Bromocresol purple-milk solids-glucose medium, proposed by Fischer and Kane in 1971 (Mycopathol. Mycol. Appl. 43:169-180, 1971) as an aid in the rapid determination of Trichophyton rubrum and Trichophyton mentagrophytes, was evaluated across a wide range of isolates to determine its accuracy and efficacy in the clinical laboratory. Results showed that it facilitated accurate determination of typical and atypical isolates of both species and also permitted the rapid identification of other closely related and similar species. Identification of all dermatophyte species tested was possible within 7 to 10 days. Occult contamination of isolates by antibiotic-resistant bacteria did not hinder identification.
Caspian Journal of Environmental Sciences, 2024
This study used to be conducted in the Graduate Studies Laboratory at the College of Science, Kirkuk University in Iraq from 11/7/2021 to 25/5/2022 with the aim of investigating the fungi causing motive pores and skin ailments, i.e., dermatomycosis in the human physique (tinea corporis) and the incidence of Trichophyton mentagrophytes. A total of 120 samples were collected from sufferers referred to the Dermatology Consultant at Azadi Teaching Hospital and some non-public clinics in Kirkuk, age groups ranging from 1 to 60 years and both genders. All samples were examined and recognized using traditional methods and using culture media for the fungi. The direct microscopic examination of the fungi showed positive results, with an infection rate of 66.66%, while the laboratory culture showed positive results, with 49.16%. The results of the phenotypic examinations of the isolated dermatophytes showed that they belong to the two genera, Trichophyton and Microsporum. The results showed that Trichophyton was the most diagnosed specimen compared to Microsporum. The least patient specimen was diagnosed, and 5 species of Trichophyton were isolated, T. mentagrophytes exhibited the highest prevalence (9.2%), while the lowest belonged to T. interdigitale (2.5%). In the case of Microsporum, two species were isolated, so that, the infection rate of males (33.33%) was higher than that of females (15.83%). The result showed the highest infection rate of T. mentagrophytes in the age group 21-30 years, while the lowest among the group 50-61. After final identification of T. mentagrophytes by PCR, the consequences of the PCR assay were sent to the Genebank website to verify the kind of fungus through comparing it with the fungi registered at this site.
Molecular identification of dermatophytes isolated in Sfax-Tunisia
Journal de Mycologie Médicale / Journal of Medical Mycology, 2010
Recently, molecular techniques have been developed for rapid and accurate alternative identification of dermatophyte. Objective.-The objective was to investigate PCR sequencing for identification of common dermatophyte species. Materials and methods.-Twenty-four samples were taken from patients with dermatophytosis. Mycological identification revealed: Trichophyton rubrum (13), Trichophyton mentagrophytes (seven), Microsporum sp. (two) and negative culture (two). PCR sequencing of chitin synthase1 gene from culture was applied for 17 strains and directly from samples for seven cases. Results.-PCR amplification of CHS1 gene gave a 450 bp fragment. Sequencing showed 97 to 99% identity. Identification of our strains by conventional methods was confirmed by PCR sequencing in 83.3% of cases. Two isolates of Microsporum sp. were reclassified as M. ferrugineum. In the two cases with negative culture, direct PCR sequencing has detected T. mentagrophytes. Conclusion.-PCR sequencing provided excellent tool for identifying strains that do not present typical morphological characteristics. It was also able to give correct identification of the first isolates of M. ferrugineum in Tunisia.
Medical Mycology, 2018
Dermatophyte infections are extremely frequent worldwide, and their epidemiological features and distribution make them one of the most frequent infections all over the world. We identified and analysed multiform T. mentagrophytes strains isolated from a silver fox (Vulpes vulpes) kept on a breeding farm. Identification of dermatophyte strains was carried out traditionally by correlating both the clinical manifestations of the infection with a micro-and macroscopic examination. To confirm the species affiliation fully, molecular differentiation methods were used. DNA was isolated from the dermatophytes with the phenol-chloroform method. The reaction of chitin synthase 1 (chs1) amplification was carried out to confirm the dermatophytes. The phylogenetic analysis was based on the ITS sequences. The polymerase chain reaction melting profile (PCR-MP) procedure was used for differentiation of dermatophyte genomes. Direct analysis of the material sampled from the clinical lesions revealed the presence of arthrospores in the samples collected from all animals with skin lesions. The macromorphology of the colonies obtained from material sampled from the same individual was not homogeneous. The PCR-MP electrophoregram indicated high variability of their genomes. Although the dermatophytes were isolated from one infected fox, no two identical genomic profiles were obtained. The PCR-MP result corresponds with the phenotypic diversity of the isolates. The findings about the multiple dermatophyte infection in one individual complicate any future epidemiology work and other clinical investigation. Previously, using only morphological characteristics, it had been assumed that one fungal isolate per patient could be diagnosed. The novel findings encourage application of the newly developed molecular typing methods in the diagnosis of dermatophytosis.