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Frontiers in Microbiology 2021Dermatophytes are a homogeneous group of species with low genetic diversity, and there are still many uncertainties about the boundaries among species.
BACKGROUND
Dermatophytes are a homogeneous group of species with low genetic diversity, and there are still many uncertainties about the boundaries among species.
OBJECTIVES
Aiming at clarifying the relationships among species in the genus and introducing suitable genes for multilocus sequence typing (MLST), a new MLST scheme approach was developed to characterize the major pathogenic dermatophytes.
METHODS
We performed maximum parsimony (MP), MrBayes, RAxML, and eBURST analyses, based on the MLST scheme to scrutinize the evolution within 95 clinical isolates and four reference strains belonging to the four major dermatophytes species. Then, the discriminatory power, pairwise genetic distances, ratio dN/dS, and sequence types (STs) of these isolates were determined. Also, to study taxonomy, sequences of the internal transcribed spacer (ITS), ( and -α (α) genes of other dermatophytes species available in the GenBank were analyzed.
RESULTS
Findings of the present study indicated that three genes: , ITS, and α, which showed the greatest diversity among dermatophyte species, were suitable for MLST. The most prevalent STs were seen among the species of . Also, two new genotypes, i.e., XXVII and XXVIII, were introduced for and . The least informative sites were found in , , and , while the most informative sites were observed in . Furthermore, the most informative locus was α. The phylogenetic tree, constructed by the combination of the three genes, shows a new topological pattern that confirms the derivation of the anthropophilic and zoophilic genera from the geophilic genus. Also, the phylogenetic analyses and pairwise distances of the combination of the three loci showed that and were a species complex, where is derived from .
CONCLUSIONS
Results of this study showed that MLST is very effective in determining the boundaries between species and taxonomy. Considering that there is no database for MLST dermatophytes, further studies are needed to determine the suitable genes for MLST. Also, the determination of STs in epidemiological studies and raising epidemiological information are helpful. This study was a new starting point to determine the ST and a foundation for a dermatophyte MLST database.
PubMed: 34149634
DOI: 10.3389/fmicb.2021.643509 -
Indian Journal of Dermatology,... 2013
Review
Topics: Diagnosis, Differential; Female; Humans; Immunocompetence; Immunocompromised Host; Infant; Tinea; Trichophyton; Young Adult
PubMed: 23760341
DOI: 10.4103/0378-6323.113109 -
International Journal of Infectious... Jan 2021
PubMed: 33197583
DOI: 10.1016/j.ijid.2020.11.144 -
Central European Journal of Public... Dec 2018A three-year retrospective study of fungi isolated from samples of patients with suspected fungal skin infections in Eastern Slovakia is presented.
OBJECTIVE
A three-year retrospective study of fungi isolated from samples of patients with suspected fungal skin infections in Eastern Slovakia is presented.
METHODS
A total of 11,989 samples were collected and investigated with direct microscopic examination using 20% KOH and cultivated in Sabouraud and Mycosel medium. Identification was based on macroscopic and microscopic characteristics.
RESULTS
Of the total samples, 61.76% (7,405/11,989) were completely negative and 38.24% positive (4,584/11,989). Dermatophytes accounted for 45.88% of isolates (2,103/4,584), yeasts for 26.79% (1,228/4,584), non-dermatophytes for 15.29% (701/4,584), and Malassezia sp. for 12.4% (552/4,584). Trichophyton rubrum was the most prevalent causative agent (79.08%) implicated in fungal skin infections, followed by Trichophyton interdigitale (10.60%). Less frequent isolates included Trichophyton tonsurans (5.13%), and Trichophyton mentagrophytes (3.14%). Other dermatophytes (Microsporum audouinii, Microsporum gypseum, Microsporum canis, Trichophyton violaceum, Trichophyton verrucosum, and Epidermophyton floccosum) were very rarely identified (each in less than 1% of all samples). The main clinical form of dermatophytosis in the sample was tinea unguium (42.61%), followed by tinea pedis (30.86%), tinea inguinalis (11.65%), tinea corporis (8.04%), and tinea manus (4.76%). Tinea capitis et faciei (2.08%) was more common among children and adolescents.
CONCLUSION
The assessment of data has showed the predominance of tinea unguium among adult patients, tinea capitis et faciei among children, and the prevalent aetiological role of Trichophyton rubrum in fungal skin infections; findings that are in agreement with recent European studies.
Topics: Adolescent; Adult; Age Distribution; Aged; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Middle Aged; Mycoses; Retrospective Studies; Sex Distribution; Slovakia; Tinea; Trichophyton; Young Adult
PubMed: 30817878
DOI: 10.21101/cejph.a5279 -
Revista Argentina de Microbiologia 2021A descriptive observational and cross-sectional study was carried out. The clinical characteristics, etiologic agents, treatments and outcome of 33 cases of tinea...
A descriptive observational and cross-sectional study was carried out. The clinical characteristics, etiologic agents, treatments and outcome of 33 cases of tinea capitis in the Mycology Unit at Francisco J. Muñiz Hospital of Buenos Aires City between January 2015 and December 2019 were analyzed. The median age of the patients was 7 years, 21 of whom were male, 3 were HIV-positive and 22 had pets. The isolated etiologic agents were the following: Microsporum canis in 22 cases, Trichophyton tonsurans in 8, Nannizzia gypsea in 2 and Trichophyton mentagrophytes in one patient. Suppurative tinea capitis (krion Celsi) was detected in 10 cases and the same number of patients presented other skin locations of their dermatophytosis in addition to those in the scalp. Twenty-one cases were orally treated with griseofulvin and 12 with terbinafine. Those patients with suppurative tinea capitis received drops of betamethasone by mouth besides the antifungal drugs. All patients had good clinical and mycological response to the treatments, all lesions disappeared, and mycological studies turned negative by the end of the treatments. We conclude that both drugs were effective for the treatment of tinea capitis; however, lesions in those cases receiving terbinafine involuted more slowly.
Topics: Antifungal Agents; Child; Cross-Sectional Studies; Griseofulvin; Humans; Male; Naphthalenes; Terbinafine; Tinea Capitis; Trichophyton
PubMed: 33618899
DOI: 10.1016/j.ram.2021.01.004 -
Japanese Journal of Infectious Diseases Mar 2018Trichophyton tonsurans, a major pathogen causing tinea capitis and tinea corporis, has been isolated from contact sports-players in Japan. The molecular types of 208...
Trichophyton tonsurans, a major pathogen causing tinea capitis and tinea corporis, has been isolated from contact sports-players in Japan. The molecular types of 208 strains isolated between 2011 and 2015 were determined to understand the contemporary Japanese epidemic. Of these, 142 were isolated from practitioners of judo, 28 from wrestlers, 7 from sumo wrestlers, and 31 from individuals with unknown backgrounds. Based on length polymorphisms of the non-transcribed spacer (NTS) region of the ribosomal RNA gene, these 208 strains were divided into 3 subtypes: NTS I (204; 98.1%), II (3; 1.4%), and III (1; 0.5%). Single nucleotide polymorphisms (SNPs) and deletion/insertion profiles in the NTS region, length polymorphisms of the alkaline protease 1 gene, and a SNP in the carboxypeptidase Y gene were identified in 50 NTS I strains isolated between 2011 and 2015, and in 10 strains isolated before 2005. All 60 strains were classified as the same molecular type, with a profile identical to that of type Ib, a major type in the United States of America. These results indicate that NTS I strains isolated in Japan are clonal and independent of the type of sports activity.
Topics: DNA, Fungal; Epidemics; Humans; Japan; Molecular Epidemiology; Molecular Typing; Tinea; Trichophyton
PubMed: 29491232
DOI: 10.7883/yoken.JJID.2017.449 -
Dermatology Online Journal Mar 2016Tinea capitis is caused by dermatophyte fungi that utilize keratin as a nutrient source. Scalp erythema, scaling, andcrusting are typical signs of this disease....
BACKGROUND
Tinea capitis is caused by dermatophyte fungi that utilize keratin as a nutrient source. Scalp erythema, scaling, andcrusting are typical signs of this disease. Although most commonly seen in prepubescent children, tinea capitis can occur in adults.
RESULTS
Endothrix tinea capitis owing to Trichophyton tonsurans commonly produces generalized scaling and localized perifollicular inflammation reminiscent of lichen planopilaris. Ectothrix tinea capitis owing to Microsporum sp. produces well- demarcated erythematous plaques suggestive of psoriasis. H&E stained biopsy specimens, KOH preparations or fungal cultures will confirm the diagnosis.
CONCLUSION
Because of a low index of suspicion for tinea capitis in adults with scaling and alopecia, diagnosis and appropriate treatment are often delayed. Resistance to treatment for seborrheic dermatitis or psoriasis should prompt a KOH, fungal culture orbiopsy to confirm the diagnosis of tinea capitis and initiate systemic antifungal agents.
Topics: Aged; Antifungal Agents; Female; Humans; Naphthalenes; Skin; Terbinafine; Tinea Capitis
PubMed: 27136624
DOI: No ID Found -
Clinical, Cosmetic and Investigational... 2022This work aimed to determine the magnitude of tinea capitis, the diversity and species composition of fungi, and the predominant dermatophytes implicated in causing...
OBJECTIVE
This work aimed to determine the magnitude of tinea capitis, the diversity and species composition of fungi, and the predominant dermatophytes implicated in causing tinea capitis.
METHODS
A prospective, cross-sectional study was conducted at a dermatology clinic. Scalp scrapings were collected and cultured, and dermatophyte and non-dermatophyte molds were identified.
RESULTS
Of 364 scalp scrapings, fungi were recovered from 301 (82.7%) clinical samples. About 60.7% of the samples were collected from women, while 39.3% were collected from male study subjects. The association between the magnitude of scalp ringworm and gender was not statistically significant ( = 0.105). Two hundred eighty study subjects were less than 15 years of age, of which 254 were culture positive. The association of tinea capitis and the age of patients was statistically significant ( = 0). Three hundred forty-nine fungal isolates were isolated, of which 54.2% were dermatophytes, while 45.8% were non-dermatophyte molds. The occurrence of dermatophytes in their decreasing order was (138; 73%), (18; 9.5%), (16; 8.5%), (8; 4.5%), (7; 3.7%), (1; 0.5%), and (1; 0.5%).
CONCLUSION
A high prevalence rate of -induced tinea capitis was reported. The magnitude of scalp ringworm in adults was remarkably high. Therefore, conducting a nationwide epidemiological survey on tinea capitis regardless of age is suggested. The isolation of many non-dermatophyte molds in the current study may shade questions about the perception that tinea capitis is caused by dermatophytes only. Therefore, studies on their potential pathogenic role on skin and skin-related (nail and the scalp) infections appear to be an active field of research.
PubMed: 35847420
DOI: 10.2147/CCID.S367763 -
Current Medical Mycology Jun 2021Superficial mycoses are the fourth most common cause of disease worldwide. It is not surprising that zoonotic transmission occurs to humans due to close contact with...
BACKGROUND AND PURPOSE
Superficial mycoses are the fourth most common cause of disease worldwide. It is not surprising that zoonotic transmission occurs to humans due to close contact with different animals, be it companion or farm animals. Therefore, the objective of this study was to determine the presence of asymptomatic dermatophyte carriers in the owner-pet pairs, identify the most common etiologic agents, and find the likely connection between the carrier status of an owner and the presence of dermatophytes in their pets.
MATERIALS AND METHODS
From May 2019 to January 2020, 21 cats and 115 dogs with their respective owners were selected for dermatophyte culture. All the dogs and cats included in the study were from the communities of southeastern Mexico. The samples were taken with a cotton swab, which was vigorously rubbed and twisted on the scalp or body of the pet four times and grown on Mycosel Agar. The isolates were identified based on macroscopic and microscopic characteristics. The prevalence of the binomial ranged from 0.73% in pet skin and human hands to 2.2% in human scalp. In humans, the agents were and , while in pets, a strain of was found.
CONCLUSION
Different species of dermatophytes were found in the owner/pet pairs, which denotes that coexistence is not related in asymptomatic cases.
PubMed: 35028482
DOI: 10.18502/cmm.7.2.7029 -
Journal of Fungi (Basel, Switzerland) Mar 2023Pediatric tinea capitis displays a wide range of prevalence, with significant variability among populations. We retrospectively extracted the medical records of 456...
Pediatric tinea capitis displays a wide range of prevalence, with significant variability among populations. We retrospectively extracted the medical records of 456 pediatric patients diagnosed with tinea capitis during the years 2010-2021, from the dermatology outpatient clinics in two tertiary medical centers. Three species were isolated in 90% of patients: , , and While presented a six-fold increase in incidence during the years 2019-2021, maintained stable incidence rates. Furthermore, terbinafine was the most efficient antifungal agent against , achieving complete clinical clearance in 95% of patients, as compared to fluconazole (68%) and griseofulvin (38%) ( < 0.001). The mycological cure was recorded in 61/90 (68%) of patients with available data, at an average of 10 weeks. For patients with , griseofulvin and fluconazole were equally efficient (73% and 66%, respectively) ( = 0.44). Kerion was described in 36% and 14% of patients with and , respectively, ( < 0.001). In conclusion, since 2019, there has been a significant increase in the prevalence of , establishing this pathogen as the most common cause for tinea capitis in our population. Our data suggest that terbinafine is effective and presents high cure rates for tinea capitis in the pediatric population.
PubMed: 36983534
DOI: 10.3390/jof9030366