Isolation of Trichophyton violaceum and Trichophyton soudanense in Baltimore, Maryland

A Road Less Traveled: E-test Method for Antifungal Susceptibility Testing in Trichophyton mentagrophyte Isolates Among Patients Presenting With Dermatophytosis at a Tertiary Healthcare Center in North India

Introduction Dermatophytosis is a common infection of the skin, hair, and nails caused by dermatophytes, a group of filamentous fungi capable of digesting and obtaining nutrients from keratin. Dermatophytes comprise three important genera: Epidermophyton, Microsporum,and Trichophyton. This study aimed to analyze the antifungal susceptibility patterns of Trichophyton mentagrophytes isolates using the epsilometer test (E-test) method. Material and methods This prospective observational study was conducted on clinically suspected cases of dermatophytosis. All samples, including skin scrapings, hair, and nails, were subjected to potassium hydroxide (KOH) examination followed by fungal culture. The Trichophyton mentagrophytes isolates were then subjected to antifungal susceptibility testing using the E-test method for the two most prescribed antifungals: itraconazole and fluconazole. Results In this study, one-third of the patients who tested positive for dermatophytosis belonged to the same family, with spouses being the most commonly affected. Tinea corporis was the most common clinical presentation, with Trichophyton mentagrophytes identified as the most common etiological agent. Itraconazole was more effective than fluconazole. Conclusion The current study demonstrated that antifungal susceptibility testing of dermatophytes using the E-test is easier and can be applied in routine laboratories as a screening method, serving as an alternative to broth microdilution.

Pediatric Tinea Capitis: A Retrospective Cohort Study from 2010 to 2021

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: T. tonsurans, M. canis, and T. violaceum. While T. tonsurans presented a six-fold increase in incidence during the years 2019–2021, M. canis maintained stable incidence rates. Furthermore, terbinafine was the most efficient antifungal agent against T. tonsurans, achieving complete clinical clearance in 95% of patients, as compared to fluconazole (68%) and griseofulvin (38%) (p < 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 M. canis, griseofulvin and fluconazole were equally efficient (73% and 66%, respectively) (p = 0.44). Kerion was described in 36% and 14% of patients with T. tonsurans and M. canis, respectively, (p < 0.001). In conclusion, since 2019, there has been a significant increase in the prevalence of T. tonsurans, 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.

Species Diversity of Mycoplankton on the Background of Selected Indicators of Water Quality in Stratified Mesotrophic Lakes

The aim of the study was to determine mycoplankton species diversity in relation to the physico-chemical parameters of lake waters. The research was carried out in the summer months in 15 mesotrophic lakes and showed a high ecological significance index for Rhodotorula glutinis, Epicoccum nigrum, Fusarium sporotrichioides, and Trichophyton violaceum. Mycoplankton abundance and species diversity decreased with the depth of water, which coincided with a decrease in oxygen content and organic matter concentration. A high concentration of nitrogen compounds (total nitrogen-TN and dissolved nitrogen-DN) limited the development of mycobiota in the hypolimnion. In the metalimnion, the intensive development of organisms, especially bacteria, limited mycoplankton abundance despite perfect physical and chemical conditions for its development. Finally, mycoplankton functioned the best in slightly alkaline waters.

Clinical clues and trends in epidemiology and pathogens in paediatric tinea capitis: a retrospective cohort study

BACKGROUND

Tinea capitis is the most common dermatophyte infection in children. Pathogens differ between populations. During the past few decades pathogen shifts have been reported in many countries around the world. This study aimed to characterize the pathogens involved in tinea capitis in a large tertiary paediatric medical centre in Israel.

METHODS

The electronic medical records of the dermatology unit were searched for patients diagnosed with tinea capitis from 2010 to 2019, and demographic, clinical and mycological data were retrieved. A stepwise logistic regression was performed to determine the variables most significantly associated with positive cultures.

RESULTS

The prevalence of Trichophyton tonsurans isolates was found to be significantly increased during 2019. In the logistic regression analysis, alopecia was most significantly associated with a positive culture (OR = 8.72, 95% CI 4.29-17.7, P < 0.001) while positive culture was also associated with age (OR = 1.11 per year of age, 95% CI 1.02-1.22, P = 0.01) and Ethiopian ethnicity (OR = 3.67, 95% CI 1.42-9.45, P = 0.01). The presentation of alopecia was significantly related to having a positive culture. This symptom was more prevalent in boys than in girls, and the diagnosis of tinea capitis was delayed by an average of 2 months in girls.

CONCLUSION

The results of this study may herald a pathogen shift in Israel. Physicians should be aware that rates of alopecia are lower in girls and this can result in delayed diagnosis and the development of complications, including chronicity, scarring alopecia and kerion formation.

Climate change, human migration, and skin disease: is there a link?

Climate change, exemplified by higher average global temperatures resulting in more frequent extreme weather events, has the potential to significantly impact human migration patterns and health. The consequences of environmental catastrophes further destabilize regions with pre-existing states of conflict due to social, political, and/or economic unrest. Migrants may carry diseases from their place of origin to their destinations and once there may be susceptible to diseases in which they had not been previously exposed to. Skin diseases are among the most commonly observed health conditions observed in migrant populations. To improve awareness among dermatologists of the burden of skin diseases among migrants, the group searched the English language scientific literature to identify articles linking climate change, migration, and skin disease. Skin diseases associated with human migration fall into three major categories: (i) communicable diseases, (ii) noncommunicable diseases, and (iii) environmentally mediated diseases. Adopting comprehensive global strategies to improve the health of migrants requires urgent attention.

Estimation of the burden of tinea capitis among children in Africa

Tinea capitis is a common and endemic dermatophytosis among school age children in Africa. However, the true burden of the disease is unknown in Africa. We aimed to estimate the burden of tinea capitis among children <18 years of age in Africa. A systematic review was performed using Embase, MEDLINE and the Cochrane Library of Systematic Reviews to identify articles on tinea capitis among children in Africa published between January 1990 and October 2020. The United Nation's Population data (2019) were used to identify the number of children at risk of tinea capitis in each African country. Using the pooled prevalence, the country-specific and total burden of tinea capitis was calculated. Forty studies involving a total of 229,086 children from 17/54 African countries were identified and included in the analysis. The pooled prevalence of tinea capitis was 23% (95% CI, 17%-29%) mostly caused by Trichophyton species. With a population of 600 million (46%) children, the total number of cases of tinea capitis in Africa was estimated at 138.1 (95% CI, 102.0-174.1) million cases. Over 96% (132.6 million) cases occur in sub-Saharan Africa alone. Nigeria and Ethiopia with the highest population of children contributed 16.4% (n = 98.7 million) and 8.5% (n = 52.2 million) of cases, respectively. Majority of the participants were primary school children with a mean age of 10 years. Cases are mostly diagnosed clinically. There was a large discrepancy between the clinical and mycological diagnosis. About one in every five children in Africa has tinea capitis making it one of the most common childhood conditions in the region. A precise quantification of the burden of this neglected tropical disease is required to inform clinical and public health intervention strategies.

Outbreak of Trichophyton soudanense causing tinea capitis in an orphanage in Myanmar

We report an outbreak of Trichophyton soudanense causing tinea capitis and corporis in an orphanage in Myanmar. The thirty orphan children were suspected to have anthropophilic tinea but zoonotic tinea could not be excluded as all children were playing with stray dogs. Direct mycological examinations of hair and scalp samples showed filaments but culture assays remained sterile. We revealed T. soudanense as the infectious agent by PCR amplification of extracted fungal DNA and further sequencing of the PCR products. Children were successfully treated by terbinafine and reinfection was prevented by hygiene measures. This case report shed the light on T. soudanense infection on another continent than Africa and on the significant help of PCR identification.

Identification and characterization of parvalbumin-like protein in Trichophyton violaceum

Parvalbumins play crucial physiological roles in neuromuscular systems of vertebrates, such as cell-cycle, development of neurons, contraction of muscles, and regulation of intracellular calcium. To perform these neuromuscular functions, parvalbumin may be in associated with other proteins including calbindin, carbonic anhydrase, and cytochrome oxidase. Humans may show an IgE-specific hypersensitivity to parvalbumins after consumption of some distinct fish species. While this protein is abundant in fish muscles, literature review of publications related to fish parvalbumins, do not point to the presence of parvalbumins in eukaryotic microbes. In this study, we propose that distantly related parvalbumins may be found in some non-fish species. Bioinformatics studies such as multiple sequence alignment (MSA), phylogenetic analysis as well as molecular-based experiments indicate that, at least two parvalbumins sequences (UniProt IDs: A0A178F775 and A0A178F7E4) with EF-hand domains and Ca²⁺-binding sites could be identified in Trichophyton violaceum, a pathogenic fungal species. It was determined that both genes consisted of a single exon and encoded for parvalbumin proteins possessing conserved amino acid motifs. Antigenicity prediction revealed antigenic sites located in both sides of the Ca²⁺-binding site of the first EF-hand domain. Our phylogenetic analysis revealed that one of parvalbumins (UniProt ID: 0A178F775) can be evolved to other parvalbumins in T. violaceum (UniProt ID: A0A178F7E4) and fish species through evolutionary phenomenon. To confirm our in-silico findings, we designed three primer pairs to detect one of the T. violaceum parvalbumins (UniProt ID: A0A178F7E4) by polymerase chain reaction (PCR); one primer pair showed a strong and specific band in agarose gel electrophoresis. To evaluate the specificity of the method, the primers were tested on extracted DNA from Trichophyton rubrum and T. mentagrophytes. The results demonstrated that the evaluated parvalbumin gene (UniProt ID: A0A178F7E4) was T. violaceum-specific and this pathogenic fungus can be differentiated from T. rubrum and T. mentagrophytes through identification of parvalbumin genes. Further studies are necessary to unravel the biochemical and physiological functions of parvalbumins in T. violaceum.

Tinea capitis: A single-institution retrospective review from 2010 to 2015

BACKGROUND/OBJECTIVE

Tinea capitis is a common infection of scalp hair in children. The prevalent etiologic organism has changed significantly over time, which may reflect the complex interaction of environmental factors, genetic predisposition, and movement of populations. We evaluate the prevalence of different infectious organisms causing tinea capitis and describe the clinical characteristics.

METHODS

A retrospective chart review of patients diagnosed with tinea capitis with tissue culture confirmation, who were seen in pediatric dermatology at a tertiary care center from 2010 to 2015. Patient demographics, culture data, and clinical characteristics were evaluated. Inflammatory pattern, characterized by presence of pustules, bogginess, or lymphadenopathy, was noted.

RESULTS

Forty-six patients with culture-positive tinea capitis were identified. In the 18 (42.9%) patients who were infected with either Trichophyton violaceum or Trichophyton soudanenese, all were of African ethnicity. In contrast, Trichophyton tonsurans was identified in a minority of African patients (3.8%), revealing a statistically significant difference between ethnicity and infective species (P-value < 0.001). T tonsurans was significantly more likely than T violaceum to exhibit an inflammatory pattern (68% vs 22%, P value < 0.027).

CONCLUSIONS

While T tonsurans remained the most common cause of tinea capitis, T violaceum and T soudanense have increased in prevalence. As these latter agents are less inflammatory, clinical diagnosis may be delayed. Studying changes in the infectious cause of tinea capitis can help us create a snapshot to better understand the evolution of our population make-up, allowing us to provide crucial quality health care to all.

Lineages Within the Trichophyton rubrum Complex

The most important species of the Trichophyton rubrum group are T. rubrum, causing mainly skin and nail infections, and T. violaceum which is mostly scalp-associated. The status of a third species, T. soudanense, has been under debate. With a polyphasic approach, using molecular phylogenetic techniques, MALDI-TOF mass spectrometry and physiological and morphological analysis, we re-evaluated the T. rubrum complex. Our results support four genetic lineages within the complex each with a distinct morphology and identifiable via MALDI-TOF MS: T. rubrum, T. violaceum, T. soudanense and the T. yaoundei clade. However, ITS and Bt2 sequencing data could not confirm these taxa as four monophyletic species. Our results also suggest that strains formerly identified as T. kuryangei and T. megninii should be considered in future taxonomic studies.

[Dermatophytosis caused by rare anthropophilic and zoophilic agents]

The basis for effective treatment of any dermatomycosis is the correct and timely identification of the pathogen, which allows the targeted choice of the most suitable antimycotic and is important for the prevention of repeated infections. In recent years, infections with dermatophytes seem to have increased. In fact, from 2007 to 2018, there was an increase in the number of samples processed in the Mycology Laboratory of the Department of Dermatology at the University Hospital Jena. The most common isolated dermatophytes between 2007 and 2018 were Trichophyton (T.) rubrum, T. interdigitale, Microsporum (M.) canis and T. benhamiae. However, dermatophytoses may also be caused by rare anthropophilic agents such as Epidermophyton floccosum, zoophiles such as T. verrucosum, T. quinckeanum or Nannizzia (N.) persicolor as well as by geophiles such as N. gypsea. Therefore, these dermatophytes should at least be known, so that in case of unusual observations investigations can be performed accordingly. Changes in the pathogen spectrum of dermatophytoses have taken place over time and it is expected that the occurrence of dermatophytes will be subject of continuous fluctuations, which may mean that the incidence of some of these "rare" dermatophytes, as described here in five clinical examples, may be changing.

Anti-dermatophytes Activity of Origanum compactum Essential Oil at Three Developmental Stages

The main aim of this study is to determine the chemical compounds of Origanum compactum essential oils (OCEO) at three phenological stages (vegetative, flowering, and post-flowering) and to evaluate their antifungal activity against three dermatophytes fungal strains: Trichophyton violaceum, Trichophyton tonsurans, and Trichophyton mentagrophytes using direct contact method. The main compounds of OCEO are carvacrol, thymol, p-cymene, and γ-terpinene. Oregano EOs showed important antifungal activities with some variability between EOs and fungal testing. At a concentration of 0.75% (v/v), the best inhibition values showed with OCEO at vegetative stage against Trichophyton mentagrophytes (95.17%), Trichophyton tonsurans (92.47%), and Trichophyton violaceum (91.41%). The OCEO at vegetative stage also showed the best IC50 (concentration of an inhibitor where the response is reduced by half) values of 52.86, 0.56, and 0.57% (v/v) against Trichophyton mentagrophytes, Trichophyton tonsurans, and Trichophyton violaceum, respectively. The findings reveal that OCEO is a good source of anti-dermatophytes agents.

Antimicrobial activity of extracts and phthalides occurring in Apiaceae plants

Apiaceae plants exhibit a broad spectrum of activities, for instance, antithrombotic, hypotensive, antioxidant, and insecticidal. They also provide a source of phthalides, which display antimicrobial activity. Considering the fact of rising resistance of both bacteria and fungi against commonly used antibiotics, developing of new naturally derived compounds is undeniably attractive approach. To our best knowledge, there are no other reviews concerning this subject in the literature. In view of above, an attempt to summarize an antimicrobial potential of isolated compounds and extracts from Apiaceae plants has been made, by specifying techniques of activity determination and methods of extraction. Techniques of antimicrobial activity evaluation are mainly based on bioautography, diffusion, and dilution methods. Therefore, we focused on in vitro data described in literature so far.

Tinea corporis due to Trichophyton violaceum: A report of two cases

Dermatophytes are Fungi which infect keratinized tissues, that is, skin epidermis, hair and nails. Trichophyton violaceum is an anthropophilic, cosmopolitan dermatophyte. It primarily causes tinea capitis and less commonly tinea corporis and tinea unguium. We present a report of two cases of tinea corporis due to T. violaceum in children. Infections due to T. violaceum are important because of its transmissibility within families and community and its potential to spread and establish in new geographical areas.

Prevalence of Tinea capitis in school going children from Mathare, informal settlement in Nairobi, Kenya

Background

Tinea capitis is a common infection especially in poor resource settings. This study was aimed at determining the prevalence Tinea capitis in children from selected schools from an urban slum in Nairobi city of Kenya.

Methods

A cross-sectional study was carried out in 150 school going children during the period between May and September 2013. A questionnaire was administered and cultures of scalps, skin scrapping/hair stubs samples were performed and the etiological agents identified and confirmed.

Results

In a total of one hundred and fifty (150) children recruited 89 (59.3%) were males and 61 (40.7%) females aged between 3 and 14 years. The overall prevalence rates in dermatophytes infection was 81.3% (122/150) with etiological agents consisting Trichophyton spp. (61.3%), Microsporum spp. (13.3%) and Epidermophyton spp. (7.3%) infections with infections occurring either singly (56%), duo (38%) or tipple co-infections (6%).

Conclusion

This study demonstrates a high prevalence of Tinea infections with Trichophyton tonsurans as the predominant etiological agent in school going children of the urban slums of Nairobi.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1240-7) contains supplementary material, which is available to authorized users.

Isolation of dermatophytes (and other fungi) from human nail and skin dust produced by podiatric medical treatments in Australia

BACKGROUND

Podiatric physicians routinely use electric drills for the treatment of nail and skin conditions. The grinding process produces human nail and skin dust that is generally vacuumed into bags in the grinding unit. Many of the nails are thought to be mycotic, particularly because they are obtained from patients with symptoms of dermatophyte infections. Currently, there is limited information available on the detection of fungi from nail dust samples. Herein, we attempt to address this situation and outline some of the difficulties that pathology laboratories face in isolating and identifying dermatophytes from nail samples.

METHODS

Fifty nail dust bags from podiatric medical clinics across all of the states and territories of Australia were collected and analyzed. Samples from the bags were inoculated onto primary isolation media. Fungal colonies that grew were then inoculated onto potato dextrose agar for identification using standard morphological (macroscopic and microscopic) features.

RESULTS

One hundred fifty-one colonies of dermatophytes were identified from 43 of the 50 samples. In addition 471 nondermatophyte molds were isolated, along with some yeasts and bacteria.

CONCLUSIONS

The most common dermatophytes isolated were from the Trichophyton mentagrophytes/interdigitale complexes. Trichophyton rubrum, Trichophyton tonsurans, Trichophyton soudanense, and Epidermophyton floccosum were also isolated. An unidentified group of dermatophytes was also present. The three most common genera of nondermatophyte molds were Aspergillus, Penicillium, and Scopulariopsis, all of which have been implicated in onychomycosis and more general disease. The presence of viable fungal pathogens in the dust could potentially pose a health problem to podiatric physicians.

Prevalence of Tinea Capitis Infection Among Primary School Children in a Rural Setting in South-West Nigeria

Dermatophyte infection is a common skin disorder. Tinea capitis, infection of the scalp and hair shaft, is the most common dermatophytosis in children aged between six months and pre-pubertal age. The aim of the study was to determine the prevalence, causative agents and to identify predisposing factors among primary school children in a rural community in Sagamu, Ogun state, Nigeria. This was a descriptive cross sectional study. Interviewer administered questionnaire was used. Following a physical examination, children with a clinical diagnosis of tinea capitis had scalp and hair scrapings for microscopy and culture. Tinea capitis was confirmed in 15.4%. Trichophyton mentagrophyte (51.7%) and Microsporum aoudouinii (20.7%) were the most prevalent organisms in this study. The most common predisposing factors were carrying of objects on the scalp; sharing of hair clippers, scissors, combs, towels and fomites. Low socioeconomic status coupled with overcrowding and poor hygiene was the major determinant of tinea capitis among the children. Tinea capitis remains a common infection among Nigerian school children. Health promotion and health education interventions are recommended to promote good hygiene, better living conditions, early identification and treatment.

Tinea capitis among children in the Columbus area, Ohio, USA

Tinea capitis is a fungal infection of the hair follicles of the scalp. In the US, the most common organisms have traditionally been Trichophyton tonsurans, and occasionally Microsporum canis. This study was designed to examine patterns of organisms causing tinea capitis and determine factors associated with infection. A retrospective database analysis was conducted to locate records of patients with tinea capitis from May 2001 to May 2006 at Nationwide Children's Hospital in Columbus, OH. Descriptive statistics, frequency analysis, chi-squared test, and Student's t-test were performed to evaluate types of causative organisms and associated patient characteristics. One hundred and eighty-nine charts of patients with a positive scalp culture for tinea capitis were located. Trichophyton tonsurans (88.9%) was the foremost causative agent followed by Trichophyton violaceum (4.2%). Tinea capitis was more prevalent among African Americans and was more common in urban areas (P < 0.05). Children of African descent inhabiting urban settings were most vulnerable to tinea capitis. The most common organism isolated in this retrospective study was T. tonsurans. Trichophyton violaceum and Trichophyton soudanense were also isolated, which are not commonly reported causes of tinea capitis in the US.

Tinea capitis due to Trichophyton soudanense in Chicago, Illinois: report of a case

The etiologic agents of tinea capitis have traditionally been very stable with respect to geographic boundaries, with different anthropophilic or zoophilic species serving as the primary agents in particular countries and even continents. With recent increases in immigration and international travel, these traditional patterns are being challenged. We report a case of tinea capitis due to Trichophyton soudanense in a West-African-born boy living in Chicago, Illinois.

Identification of dermatophytes by an oligonucleotide array

Species of dermatophytes are classified into three anamorphic (asexual) genera, Epidermophyton, Microsporum, and Trichophyton. Conventional methods used to identify dermatophytes are often lengthy and may be inconclusive because of atypical microscopic or colony morphology. Based on the internal transcribed spacer 1 (ITS-1) and ITS-2 sequences of the rRNA genes, an oligonucleotide array was developed to identify 17 dermatophyte species. The method consisted of PCR amplification of the ITS regions using universal primers, followed by hybridization of the digoxigenin-labeled PCR products to an array of oligonucleotides (17- to 30-mers) immobilized on a nylon membrane. Of 198 dermatophyte strains and 90 nontarget strains tested, the sensitivity and specificity of the array were 99.5% and 97.8%, respectively. The only strain not identified (Microsporum audouinii LMA 597) was found to have a nucleotide insertion at the ITS-2 region where the probe was designed. Two nontarget strains, Microsporum equinum LMA 40396666 and Trichophyton gourvilii var. intermedium CBS 170.65, were misidentified as Microsporum canis and Trichophyton soudanense, respectively. Sequence analysis of the ITS regions revealed that the two misidentified strains displayed high sequence homology with the probes designed for M. canis and T. soudanense, respectively. The present method can be used as a reliable alternative to conventional identification methods and can be completed with isolated colonies within 24 h.