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Medical Mycology Journal 2023Microsporum canis, a major causative agent of zoonotic dermatophytosis, has become prevalent in Japan. Molecular epidemiological surveys using multilocus microsatellite...
Microsporum canis, a major causative agent of zoonotic dermatophytosis, has become prevalent in Japan. Molecular epidemiological surveys using multilocus microsatellite typing (MLMT), a sensitive genotyping tool for fungi, have been conducted to reveal intraspecies polymorphisms of M. canis.The present study utilized MLMT optimized for Japanese strains of M. canis to analyze epidemic trends of fungal infection. Six individual loci were targeted; namely, MS1, 2, 4, 5, 6, and 7. Analysis of data from 1974 through 2022 identified 416 strains, which were sorted into 60 genotypes by MLMT.The major genotypes showed changes in dominance during this period-changes that may reflect historical increases and decreases in the numbers of patients infected with M. canis patients. The main origins of infection included animal breeders and pet stores, as well as stray cat communities. Forty-nine episodes of familial outbreaks and cohabitant animal infections were recorded, and genotypes responsible for each episode were determined. MLMT analysis is not only a robust tool to understand population structures, but likely the most suitable method for tracking M. canis infections.
Topics: Animals; Cats; Japan; Molecular Epidemiology; Microsporum; Canidae; Microsatellite Repeats
PubMed: 37648500
DOI: 10.3314/mmj.23-00003 -
Mycoses Dec 2023Tinea capitis (TC), a fungal infection that occurs in children, is primarily caused by dermatophytes such as Trichophyton and Microsporum species. For Trichophyton...
BACKGROUND
Tinea capitis (TC), a fungal infection that occurs in children, is primarily caused by dermatophytes such as Trichophyton and Microsporum species. For Trichophyton species, treatment with terbinafine is considered more effective than griseofulvin treatment. Specific populations, such as refugee children, are more susceptible to TC.
OBJECTIVE
This study aimed to describe and compare the response to treatment among Israeli and refugee children with TC.
PATIENTS/METHODS
We retrospectively reviewed data collected on refugee and Israeli children with TC between January 2004 and January 2020.
RESULTS
Overall, 3358 children with TC (refugees: 1497; Israelis: 1861) were identified. Among these, 86% of the refugee children had TC caused by Trichophyton violaceum, 65% of the Israeli children had TC caused by Microsporum canis and 83% of all children were treated with griseofulvin. Overall, 14% of the refugees showed a partial response to a griseofulvin dose of ≤25 mg/kg/day; however, they showed a complete response upon increasing the dose to ≥30 mg/kg/day. No significant adverse effects were observed.
CONCLUSION
The over-crowded day care centres and dense living make refugee children more susceptible to TC than the general population, and griseofulvin dosage adjustment is necessary. TC, due to Trichophyton species, could benefit from receiving an increased dose of griseofulvin in a suspension form, which is cheaper than terbinafine.
Topics: Humans; Child; Griseofulvin; Terbinafine; Antifungal Agents; Israel; Refugees; Retrospective Studies; Naphthalenes; Tinea Capitis; Microsporum; Trichophyton
PubMed: 37620517
DOI: 10.1111/myc.13651 -
Journal of Basic Microbiology Jan 2024Dermatophytes are highly infectious fungi that cause superficial infections in keratinized tissues in humans and animals. This group of fungi is defined by their ability...
Dermatophytes are highly infectious fungi that cause superficial infections in keratinized tissues in humans and animals. This group of fungi is defined by their ability to digest keratin and encompasses a wide range of species. We investigated a critical adhesion protein, subtilisin 3, utilized by Microsporum canis during initial stages of infection, analyzing its production and expression under varying growth conditions. Additionally, as this protein must be expressed and produced for dermatophyte infections to occur, we developed and optimized a diagnostic antibody assay targeting this protein. Subtilisin 3 levels were increased in culture when grown in baffled flasks and supplemented with either l-cysteine or cat hair. As subtilisin 3 was also produced in cultures not supplemented with keratin or cysteine, this study demonstrated that subtilisin 3 production is not reliant on the presence of keratin or its derivatives. These findings could help direct future metabolic studies of dermatophytes, particularly during the adherence phase of infections.
Topics: Animals; Humans; Subtilisin; Dermatomycoses; Keratins; Microsporum
PubMed: 37551993
DOI: 10.1002/jobm.202300125 -
Archives of Iranian Medicine Aug 2022Dermatophytosis still remains a major public health concern worldwide, particularly in developing countries. This study was undertaken to determine the etiological and...
BACKGROUND
Dermatophytosis still remains a major public health concern worldwide, particularly in developing countries. This study was undertaken to determine the etiological and epidemiological factors of dermatophyte infections in Tehran, Iran.
METHODS
A total of 1530 patients clinically suspected of cutaneous fungal infections were examined in two hospitals over a period of 10 years (2010-2020). Samples were analyzed using direct microscopic examination and culture. Data regarding age, gender, and clinical manifestations were also recorded.
RESULTS
Out of 1530 cases examined, dermatophytes were detected in 493 (32.2%) patients. Of these patients, 288 (58.4%) were males and 205 (41.6%) were females. The most affected age group was the 25-44 years old (31.6%). Tinea corporis (n=134) was the most prevalent type of ringworm, followed by tinea cruris (n=131), tinea pedis (n=90), tinea manuum (n=65), tinea unguium (n=29), tinea faciei (n=20), tinea capitis (n=18), and tinea barbae (n=2). Both tinea cruris (<0.001) and tinea pedis (=0.002) had a significant association with male gender. As for etiological agents, (29.0%) was the most frequent isolate, followed by T (25.8%), (25.3%), (6.9%), (4.9%), (4.5%), (2.0%), and (1.6%).
CONCLUSION
Dermatophytes are still the prevailing causes of fungal infection of the skin, hair, and nails in Iran. Further studies with larger samples sizes and inclusion of diverse locations would yield more accurate results.
Topics: Female; Humans; Male; Adult; Tinea Pedis; Retrospective Studies; Tinea cruris; Iran; Tinea
PubMed: 37543872
DOI: 10.34172/aim.2022.82 -
IMA Fungus Jul 2023The Microsporum canis complex consists of one zoophilic species, M. canis, and two anthropophilic species, M. audouinii and M. ferrugineum. These species are the most...
The Microsporum canis complex consists of one zoophilic species, M. canis, and two anthropophilic species, M. audouinii and M. ferrugineum. These species are the most widespread zoonotic pathogens causing dermatophytosis in cats and humans worldwide. To clarify the evolutionary relationship between the three species and explore the potential host shift process, this study used phylogenetic analysis, population structure analysis, multispecies coalescent analyses, determination of MAT idiomorph distribution, sexual crosses, and macromorphology and physicochemical features to address the above questions. The complex of Microsporum canis, M. audouinii and M. ferrugineum comprises 12 genotypes. MAT1-1 was present only in M. canis, while the anthropophilic entities contained MAT1-2. The pseudocleistothecia were yielded by the mating behaviour of M. canis and M. audouinii. Growth rates and lipase, keratinolysis and urea hydrolytic capacities of zoophilic M. canis isolates were all higher than those of anthropophilic strains; DNase activity of M. ferrugineum exceeded that of M. canis. The optimum growth temperature was 28 °C, but 22 °C favoured the development of macroconidia. Molecular data, physicochemical properties and phenotypes suggest the adaptation of zoophilic M. canis to anthropophilic M. ferrugineum, with M. audouinii in an intermediate position.
PubMed: 37488659
DOI: 10.1186/s43008-023-00120-x -
Mycoses Oct 2023Dermatophytosis is one of the most common fungal infections worldwide. The distribution of dermatophytes varies across continents, but the genera Trichophyton and...
BACKGROUND
Dermatophytosis is one of the most common fungal infections worldwide. The distribution of dermatophytes varies across continents, but the genera Trichophyton and Microsporum have emerged as the main isolated agents in humans and animals.
OBJECTIVES
To validate Drosophila melanogaster flies as a fast and feasible model to study dermatophytic infections.
METHODS
Wild-type (WT) and Toll-deficient D. melanogaster flies were infected by Trichophyton rubrum, T. mentagrophytes, Microsporum canis and Nannizzia gypsea by pricking with a needle previously dipped in inoculum concentrations ranging from 10 to 10 colony-forming units/mL. Establishment of infection was confirmed by survival curves, histopathological analysis and fungal burden. Thereafter, flies were treated with terbinafine, itraconazole and clioquinol.
RESULTS
WT flies were predominantly resistant to the infection, whereas Toll-deficient flies succumbed to the four dermatophyte genera tested. The antifungal drugs protected flies from the infection, except for N. gypsea whose survival curves did not differ from the untreated group.
CONCLUSIONS
This pilot study confirms that D. melanogaster is a suitable model to study the virulence and antifungal drug efficacy in dermatophyte species.
Topics: Humans; Animals; Antifungal Agents; Drosophila melanogaster; Pilot Projects; Arthrodermataceae; Itraconazole; Trichophyton; Tinea
PubMed: 37434424
DOI: 10.1111/myc.13630 -
Medical Mycology Jul 2023Human infections by Trichophyton mentagrophytes occur mainly due to contact with diseased animals. In Iran, T. mentagrophytes genotype V is the most prevalent variant of...
Human infections by Trichophyton mentagrophytes occur mainly due to contact with diseased animals. In Iran, T. mentagrophytes genotype V is the most prevalent variant of the fungus. We aimed to determine the animal reservoir of T. mentagrophytes genotype V infection. The study was done on a total of 577 dermatophyte strains obtained from animals with signs of dermatophytosis and human patients. The list of extensively sampled animals included sheep, cows, cats and dogs. For human cases, epidemiological data were collected. All dermatophyte isolates from animals along with 70 human isolates morphologically similar to T. verrucosum and T. mentagrophytes genotype V were identified by rDNA internal transcribed spacer region restriction fragment length polymorphism analysis and DNA sequencing. A total of 334 animal dermatophyte strains were identified as Microsporum canis, T. mentagrophytes genotype V, T. verrucosum, Nannizzia gypsea, T. mentagrophytes genotype II*, T. mentagrophytes genotype VII, T. quinckeanum, and N. fulva. All clinical isolates identified as T. mentagrophytes genotype V originated from skin and scalp infections. Almost all veterinary isolates of T. mentagrophytes genotype V were cultured from sheep, but epidemiological data on animal-to-human transmission of T. mentagrophytes genotype V infection were limited and we found evidence in favor of interhuman transmission. In Iran, sheep maintain T. mentagrophytes genotype V population and therefore serve as animal reservoir of respective infections. The role of sheep as the source of human dermatophytosis due to T. mentagrophytes genotype V isolates is yet to be proven.
Topics: Female; Humans; Animals; Cats; Sheep; Cattle; Dogs; Trichophyton; Tinea; Genotype; DNA, Ribosomal
PubMed: 37429606
DOI: 10.1093/mmy/myad066 -
Acta Crystallographica. Section C,... Aug 2023Monocrystals of dinuclear μ-1,4-bis(3-aminopropyl)piperazine-κN,N:N,N-bis[bis(tri-tert-butoxysilanethiolato-κS)cadmium(II)], [Cd(CHOSSi)(CHN)] or...
Solvent influence on the crystal structures of new cadmium tri-tert-butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity.
Monocrystals of dinuclear μ-1,4-bis(3-aminopropyl)piperazine-κN,N:N,N-bis[bis(tri-tert-butoxysilanethiolato-κS)cadmium(II)], [Cd(CHOSSi)(CHN)] or [Cd{SSi(OtBu)}(μ-BAPP)], 1, and polynuclear catena-poly[[bis(tri-tert-butoxysilanethiolato-κS)cadmium(II)]-μ-1,4-bis(3-aminopropyl)piperazine-κN:N], [Cd(CHOSSi)(CHN)] or [Cd{SSi(OtBu)}(μ-BAPP)], 2, with 1,4-bis(3-aminopropyl)piperazine (BAPP) and tri-tert-butoxysilanethiolate ligands, were obtained from the same ratio of reactants, but with different solvents used for the crystallization processes. The structures and properties of both complexes were characterized using elemental analysis, X-ray diffraction and FT-IR, H NMR and luminescence spectroscopy. Applied density functional theory (DFT) computational methods and noncovalent interaction (NCI) analysis were used for geometry optimization and visualization of the interactions between the metallic centres and their surroundings. The X-ray analysis revealed four-coordinate Cd centres bound to two S atoms of the silanethiolate groups and two N atoms of the BAPP ligand; however, it chelates to tertiary and primary N atoms in 1, whilst in 2 it does not chelate and bonds only to RNH. The photoluminescence properties of complexes 1 and 2 result from free-ligand emission and differ significantly from each other with respect to emission intensity. Additionally, antifungal activity was investigated against 18 isolates of fungi. Compound 1 strongly inhibited the growth of three dermatophytes: Epidermophyton floccosum, Microsporum canis and Trichophyton rubrum.
PubMed: 37405860
DOI: 10.1107/S2053229623005442 -
Mycopathologia Oct 2023The aim of this study was to analyze the epidemiological characteristics and pathogen spectrum of tinea capitis in Guangxi, southern China. A multicenter prospective...
The aim of this study was to analyze the epidemiological characteristics and pathogen spectrum of tinea capitis in Guangxi, southern China. A multicenter prospective descriptive study was conducted in 8 hospitals across Guangxi. From January 2019 to July 2022, one hundred seventy-one (171) patients diagnosed with tinea capitis were included. Demographic data, risk factors, and fungal data were collected. If necessary, species were further identified by morphological or molecular sequencing in the central laboratory. Of the 171 cases of tinea capitis, 74.3% occurred in patients aged 2-8 years. Children with tinea capitis were mainly boys (59.6%) and were more likely than adults to have a history of animal contact (44.2% vs. 33.3%) and zoophilic dermatophyte infection (76.9% vs. 46.7%, P = 0.008). The adults were mainly female (53%) and were more likely than children to have a history of infection with anthropophilic organisms (53.3% vs. 18.9%). The causative agents of tinea capitis in Guangxi were diverse, and the most common pathogen was Microsporum canis (M. cani, n = 98, 62%), followed by Trichophyton mentagrophytes (T. mentagrophytes n = 18, 11.4%) and Trichophyton tonsurans (T. tonsurans n = 12, 7.6%). In addition, tinea capitis caused by Nannizzia incurvata (N. incurvata) and Trichophyton verrucosum (T. verrucosum) was detected in the study. Notably, the proportion of patients with kerion in the study was 41.5% (n = 71), and most of those patients were children (n = 68), especially neglected children living in the rural mountainous areas of Guangxi, where they were unable to receive timely diagnosis and appropriate treatment. In conclusion, the causative agents of tinea capitis in Guangxi, South China, are diverse, and the incidence of kerion is high, indicating that diagnosis and treatment modalities in the region remain grossly inadequate. Clinicians and policy-makers should collaborate to adopt public health strategies to control the disease.
Topics: Child; Male; Adult; Animals; Humans; Female; China; Tinea Capitis; Microsporum; Risk Factors; Hospitals; Incidence; Trichophyton
PubMed: 37356056
DOI: 10.1007/s11046-023-00762-w -
Emerging Microbes & Infections Dec 2023Genomes of strains of the zoophilic dermatophyte from invasive (disseminated and subcutaneous) and noninvasive (tinea capitis) infections were compared. Especially the...
Genomes of strains of the zoophilic dermatophyte from invasive (disseminated and subcutaneous) and noninvasive (tinea capitis) infections were compared. Especially the disseminated strain showed significant syntenic rearrangements, including multiple translocations and inversions, and numerous SNPs and Indels in comparison to the noninvasive strain. In transcriptome analysis, both invasive strains were enriched for GO pathways related to components of the membrane, iron binding and heme binding, which possibly enables them to invade deeper into dermis and blood vessels. At 37 °C, invasive strains showed gene expression enriched for DNA replication, mismatch repair, N-glycan biosynthesis and ribosome biogenesis. The invasive strains were slightly less susceptible to multiple antifungal agents suggesting that acquired elevated drug resistance might be involved in the refractory disease courses. Patient with disseminated infection failed to respond to a combined antifungal treatment with itraconazole, terbinafine, fluconazole and posaconazole.
Topics: Humans; Transcriptome; Tinea Capitis; Microsporum; Antifungal Agents
PubMed: 37288745
DOI: 10.1080/22221751.2023.2219346