The current Indian epidemic of superficial dermatophytosis due to Trichophyton mentagrophytes-A molecular study

Clinico-mycological and therapeutic updates on cutaneous dermatophytic infections in the era of Trichophyton indotineae

Trichophyton indotineae has emerged as a novel dermatophyte species resulting in treatment recalcitrant skin infections. While the earliest reports came from India, T. indotineae has now spread to many parts of the world and is rapidly becoming a global health concern. Accurate identification of T. indotineae requires elaborate mycological investigations which is beyond the domain of routine microbiology testing. Extensive, non-inflammatory and atypical presentations are commonly seen with this novel species. T. indotineae shows an alarmingly high rate of mutations in the squalene epoxidase gene leading to lowered in vitro susceptibility to terbinafine. This has also translated into a lowered clinical response and requirement of a higher dose and much longer durations of treatment with the drug. Although the species remains largely susceptible to itraconazole, prolonged treatment durations are required to achieve cure with itraconazole. Fluconazole and griseofulvin do not have satisfactory in vitro or clinical activity. Apart from requirement of prolonged treatment durations, relapse postsuccessful treatment is a distressing and yet unexplained consequence of this "species-shift." Use of third generation azoles and combinations of systemic antifungals is unwarranted as both have not demonstrated clear superiority over itraconazole given alone, and the former is an important class of drugs for invasive mycoses.

Asymptomatic colonization of stray dogs and domestic cats with Trichophyton mentagrophytes II* in Northern Iran

BACKGROUND

Despite changes in the epidemiology of dermatophyte infections, the incidence of fungal infections associated with Trichophyton species still remains high among dogs and cats. The objective of the present study was to isolate and characterize dermatophytes from dogs and cats in Iran.

METHOD

From December 2022 to May 2023, skin and hair samples were collected from symptomatic and asymptomatic cats and dogs in Mazandaran, a northern province of Iran. The samples were then inoculated into Mycosel™ Agar. Dermatophyte isolates were identified by sequencing the internal transcribed spacer region. Antifungal susceptibility tests were conducted using the Clinical and Laboratory Standards Institute (CLSI-M38-A3).

RESULT

Of the 250 samples collected (from 200 dogs and 50 cats), 20 (from 19 dogs and one cat) (8.0 %) were positive for dermatophyte growth. Based on sequence and phylogenetic analysis, all isolates belonged to T. mentagrophytes II*. Of these positive samples, 14 (70.0 %), 3 (15.0 %), 2 (10.0 %), and 1 (2.0 %) were isolated from asymptomatic stray dogs, symptomatic stray dogs, symptomatic domestic dogs, and symptomatic cats, respectively. Luliconazole and terbinafine displayed potent activity against all T. mentagrophytes isolates, with Minimum inhibitory concentration (MIC) values of 0.016 µg/ml. Miconazole and griseofulvin demonstrated higher MIC (1 and 8 µg/ml).

CONCLUSION

The present study indicated that T. mentagrophytes II* asymptomatic carriage is frequent in stray dogs in Iran. The potential risk to public health needs to be evaluated However, T. mentagrophytes genotype VIII, considered as an endemic and emerging human pathogenic clone in several countries, was not detected during the present survey.

Increased terbinafine resistance among clinical genotypes of Trichophyton mentagrophytes/T. interdigitale species complex harboring squalene epoxidase gene mutations

Terbinafine resistance has become epidemic as an emerging problem in treatment of dermatohpytosis. This could be attributed in part to a point mutation in the squalene epoxidase (SQLE) gene. In this study, point mutations in the SQLE gene were studied in T. rubrum and T. mentagrophytes/T. interdigitale species complex as two main causative agents of dermatophytosis. Antifungal susceptibility of clinical isolates of T. rubrum (n = 27) and T. mentagrophytes/T. interdigitale (n = 56) was assessed using the M38-3rd edition CLSI method. The SQLE gene and ITS region were sequenced for all the fungal strains, and the mutation sites and genotypes of the terbinafine-resistant strains were characterized. The results demonstrated that, in T. rubrum, the minimum inhibitory concentration of terbinafine (MIC50 and MIC90) was 0.03 μg/ml, and the geometric mean (G mean) concentration was 0.02. For the T. mentagrophytes complex, the MIC50 and MIC90 were 0.03 and 1.0 μg/ml, respectively, and the G mean concentration was 0.04 μg/ml. Four out of the five resistant strains were T. indotineae harboring the F397L and Q408L mutations, while the last one was T. mentagrophytes genotype VII, which harbors the F397L mutation. T. indotineae was the prominent causative agent of terbinafine resistance, with 80 % of the isolates, and T. mentagrophytes genotype VII was introduced as a new genotype in the terbinafine-resistant T. mentagrophytes complex. Our findings further substantiate the importance of antifungal susceptibility testing in selecting the choice of drug for effective treatment of dermatophytosis and highlight the importance of screening dermatophyte species for point mutations responsible for newly developed resistant strains to improve the current knowledge of overcoming infections caused by resistant species.

High Prevalence of Terbinafine Resistance Among Trichophyton mentagrophytes/T. interdigitale Species Complex, a Cross-Sectional Study from 2021 to 2022 in Northern Parts of Iran

Treatment-resistant dermatophytosis caused by the members of the Trichophyton mentagrophytes/Trichophyton interdigitale species group (TMTISG) is increasing worldwide. We aimed to determine the prevalence of TMTISG in patients with dermatophytosis in two centers from north of Iran and detect the possible mutations in the squalene epoxidase (SQLE) gene in relevant terbinafine (TRB) resistant pathogenic isolates. From November 2021 to December 2022, 1960 patients suspected to dermatophytosis and referred to two mycology referral laboratories in the north of Iran were included in the study. Identification of all dermatophyte isolates was confirmed by RFLP of rDNA internal transcribed spacer (ITS) regions. Antifungal susceptibility testing against five common antifungals using the CLSI-M38-A3 protocol was performed. The TMTISG isolates resistant to TRB, were further analyzed to determine the possible mutations in the SQLE gene. Totally, 647 cases (33%) were positive for dermatophytosis of which 280 cases (43.3%) were identified as members of TMTISG. These were more frequently isolated from tinea corporis 131 (44.56%) and tinea cruris 116 (39.46%). Of 280 TMTISG isolates, 40 (14.3%) were resistant to TRB (MIC ≥ 4 µg/mL), all found to be T. indotineae in ITS sequencing. In SQLE sequencing 34 (85%) of TRB-resistant isolates had coincident mutations of Phe397Leu and Ala448Thr whereas four and two isolates had single mutations of Phe397Leu and Leu393Ser, respectively. Overall, the resistance of Iranian TMTISG isolates to TRB greatly occurred by a mutation of Phe397Leu in the SQLE gene as alone or in combination with Ala448Thr. Nevertheless, for the occurrence of in vitro resistance, only the presence of Phe397Leu mutation seems to be decisive.

Clinical Use of Super-Bioavailable Itraconazole for the Management of Dermatophytosis: Consensus Statement by Dermatologists from India via the Modified Delphi Technique

Super-bioavailable itraconazole (SB ITZ) overcomes the limitations of conventional itraconazole (CITZ) such as interindividual variability and reduced bioavailability. It has been approved for systemic mycoses in Australia and Europe as 50 mg and the USA as 65 mg and in India as 50 mg, 65 mg, 100 mg, and 130 mg. However, data on the ideal dose and duration of SB ITZ treatment in managing dermatophytosis are insufficient. This consensus discusses the suitability, dosage, duration of treatment, and relevance of using SB ITZ in managing dermatophytosis in different clinical scenarios. Sixteen dermatologists (>15 years of experience in the field and ≥2 years clinical experience with SB ITZ), formed the expert panel. A modified Delphi technique was employed, and a consensus was reached if the concordance in response was >75%. A total of 26 consensus statements were developed. The preferred dose of SB ITZ is 130 mg once daily and if not tolerated, 65 mg twice daily. The preferred duration for treating naïve dermatophytosis is 4-6 weeks and that for recalcitrant dermatophytosis is 6-8 weeks. Moreover, cure rates for dermatophytosis are a little better with SB ITZ than with CITZ with a similar safety profile as of CITZ. Better patient compliance and efficacy are associated with SB ITZ than with CITZ, even in patients with comorbidities and special needs such as patients with diabetes, extensive lesions, corticosteroid abuse, adolescents, and those on multiple drugs. Expert clinicians reported that the overall clinical experience with SB ITZ was better than that with CITZ.

Hypothalamus-pituitary-adrenal axis (HPA axis) suppression with inappropriate use of steroids in recalcitrant dermatophytosis - A cross-sectional study

Background

Improper use of over-the-counter (OTC) steroid medication has been linked to recalcitrant dermatophytosis. There is proven evidence of HPA axis suppression by the use of long-term oral steroids. This study aims to determine the prevalence and pattern of inappropriate OTC steroid use and its effects on the hypothalamus-pituitary-adrenal (HPA) axis in adults with recalcitrant dermatophytosis.

Materials and Methods

This cross-sectional study of 2 months was conducted in a hospital setting and included patients of recalcitrant dermatophytosis with a history of OTC steroid use. Clinico-demographic details and basal serum cortisol levels were recorded in all and analyzed.

Result

Of a total of 103 patients, 59.22% (n = 61/103) were males, and the mean duration of steroid abuse was 17.78 months. About 48.54% (n = 50/103), 3.88% (n = 4/103), and 47.57% (n = 49/103) patients reported the use of topical steroids, oral steroids, and both oral and topical steroids, respectively. Among all the topical steroid users (n = 99), clobetasol propionate 48.48% (n = 48/99), while among oral steroid users (n = 53), prednisolone 45.28% (n = 24/53) were the most commonly used agents, respectively. The morning serum cortisol levels (8-9 AM) were found to be decreased in 42.7% (n = 44/103), with a mean value of 44.28 ± 17.34 μg/dL.

Conclusion

Improper OTC steroid use in recalcitrant dermatophytosis leads to HPA axis suppression. This highlights the need for intervention from apex health officials.

Emerging Antifungal Resistance in Fungal Pathogens

Purpose of Review

Over recent decades, the number of outbreaks caused by fungi has increased for humans, plants (including important crop species) and animals. Yet this problem is compounded by emerging antifungal drug resistance in pathogenic species. Resistance develops over time when fungi are exposed to drugs either in the patient or in the environment.

Recent Findings

Novel resistant variants of fungal pathogens that were previously susceptible are evolving (such as Aspergillus fumigatus) as well as newly emerging fungal species that are displaying antifungal resistance profiles (e.g. Candida auris and Trichophyton indotineae).

Summary

This review highlights the important topic of emerging antifungal resistance in fungal pathogens and how it evolved, as well as how this relates to a growing public health burden.

Resistance Profile, Terbinafine Resistance Screening and MALDI-TOF MS Identification of the Emerging Pathogen Trichophyton indotineae

The emerging pathogen Trichophyton indotineae, often resistant to terbinafine (TRB), is known to cause severe dermatophytoses such as tinea corporis and tinea cruris. In order to achieve successful treatment for these infections, insight in the resistance profile of T. indotineae strains and rapid, reliable identification is necessary. In this research, a screening medium was tested on T. indotineae strains (n = 20) as an indication tool of TRB resistance. The obtained results were confirmed by antifungal susceptibility testing (AST) for TRB following the in vitro broth microdilution reference method. Additionally, AST was performed for eight other antifungal drugs: fluconazole, itraconazole, voriconazole, ketoconazole, griseofulvin, ciclopirox olamine, naftifine and amorolfine. Forty-five percent of the strains were confirmed to be resistant to terbinafine. The TRB resistant strains showed elevated minimal inhibitory concentration values for naftifine and amorolfine as well. DNA sequencing of the squalene epoxidase-encoding gene showed that TRB resistance was a consequence of missense point mutations in this gene, which led to amino acid substitutions F397L or L393F. MALDI-TOF MS was used as a quick, accurate identification tool for T. indotineae, as it can be challenging to distinguish it from closely related species such as Trichophyton mentagrophytes or Trichophyton interdigitale using morphological characteristics. While MALDI-TOF MS could reliably identify ≥ 95% of the T. indotineae strains (depending on the spectral library), it could not be used to successfully distinguish TRB susceptible from TRB resistant strains.

[Conventional and molecular diagnostics in onychomycosis-part 1 : Conventional differentiation of dermatophytes-Trichophyton rubrum, Trichophyton interdigitale]

Onychomycosis is a common infectious nail disease occurring worldwide. The mycological diagnosis of onychomycosis is primarily used for differential diagnostic differentiation from other, mostly inflammatory nail diseases, such as nail psoriasis or onychodystrophies of other causes. Conventional laboratory diagnostics when onychomycosis is suspected is based on microscopic detection of fungi in the nail material using fluorescence-optical potassium hydroxide preparations and culture of the pathogen. Molecular amplification methods allow a more sensitive and specific identification of the causative dermatophyte. Here, in 108 patients with onychomycosis, the dermatophytes were identified by culture and/or molecular biology using polymerase chain reaction (PCR) and the species identification was confirmed with subsequent sequencing. The dermatophytes were analyzed based on macromorphological and microscopic features. A dermatophyte was cultured in 56 of the 108 patients. Among them were 31 isolates of Trichophyton (T.) rubrum and 25 of T. interdigitale. All species identifications were subsequently confirmed by rDNA sequencing with concordant results in 54 of 56 patients. Two primarily as T. interdigitale identified specimens were revealed to be T. quinckeanum and T. tonsurans by molecular methods. T. quinckeanum, which is a zoophilic dermatophyte and a so-called emerging pathogen in dermatomycology, was isolated here for the first time as the causative agent of onychomycosis. The other dermatophyte, initially thought to be T. interdigitale, turned out to be T. tonsurans on molecular biology. This anthropophilic dermatophyte is also a rarity in onychomycosis. In addition, T. rubrum was identified by PCR in 34 of the 52 nail specimens that did not grow culture, and T. interdigitale in 18 nail specimens. However, the morphological identification of the four different dermatophytes species proved problematic. Neither the colony morphology nor the microscopic features of the dermatophytes allow clear differentiation of the pathogens. Microconidia, macroconidia, chlamydospores, and arthrospores are inconsistent in occurrence, number, microscopic distribution, and shape. The urease activity also did not allow an assignment of the dermatophyte species. These results indicate that the most sensitive detection and reliable identification of causative dermatophytes in onychomycosis is only possible by molecular methods.

Diagnosis of a recurred lesion in dermatophytosis patients after 2 weeks of antifungal therapy: A prospective observational study

Few researchers believe that various risk factors may complicate the course of dermatophytosis and/or develop various dermatoses unrelated to fungal infection at the previous lesion site. However, there is a paucity of studies that analyzed the diagnosis of lesions that recurred at the treated site of dermatophytosis.

Materials and Methods

A prospective observational study was conducted on 157 cases of dermatophytosis with positive fungal test results. A fixed dose of 100 mg of oral itraconazole once daily was administered to all patients for 2 weeks. At the end of 2 weeks, patients were assessed for clinical cure and recurrence. Recurred cases were assessed for mycological profile using a fungal test (potassium hydroxide mount and/or fungal culture) for identifying fungal infection.

Results

Only eight (5.36%) patients showed clinical cure, and 141 (94.63%) patients developed recurrence after therapy. Of the 141 cases with recurrence, only 47 (33.33%) patients were positive for fungus. Eight (5.09%) patients were lost to follow-up. Frequently encountered risk factors in the study were topical steroid use, disease in family, associated atopic dermatitis and contact with pets.

Conclusion

This is the first study that described the clinical diagnosis and mycological profile of the various lesions recurring at the previous tinea infection site in patients with dermatophytosis. Such patients presented not only with recurrent lesions of fungal infection but also developed various dermatoses unrelated to fungal infection at the sites of previous tinea infection. Various factors, which could have resulted in the observed changes, are reinfection by dermatophytes at the sites of previous tinea infection, inadequate antifungal therapy or antifungal resistance; or due to the effects of various topical steroid formulations used by the patients, such as anti-inflammatory or immunosuppressive effects or shift in immunity. Hence, diagnosis of the recurrent lesion at the site of previous dermatophytosis must be individualized and should be based on 1) duration of antifungal therapy received, 2) associated risk factors, 3) response to antifungal therapy, 4) evolution of the recurrent lesion, and/or 5) fungal tests.

Changes in fungal taxonomy: mycological rationale and clinical implications

Numerous fungal species of medical importance have been recently subjected to and will likely continue to undergo nomenclatural changes as a result of the application of molecular approaches to fungal classification together with abandonment of dual nomenclature. Here, we summarize those changes affecting key groups of fungi of medical importance, explaining the mycological (taxonomic) rationale that underpinned the changes and the clinical relevance/importance (where such exists) of the key nomenclatural revisions. Potential mechanisms to mitigate unnecessary taxonomic instability are suggested, together with approaches to raise awareness of important changes to minimize potential clinical confusion.

Hedgehog Dermatophytosis: Understanding Trichophyton erinacei Infection in Pet Hedgehogs and Its Implications for Human Health

Pet hedgehogs, which are increasingly favoured companions, have garnered attention due to their potential as carriers of zoonotic diseases. These small insectivorous mammals, native to Europe, Asia, and Africa, are commonly kept as pets. The encroachment of humans into hedgehog habitats has brought these animals closer to people, raising concerns about disease transmission. This article reviews the current knowledge regarding zoonotic disease associated with pet hedgehogs, with a particular focus on mycotic infections caused by Trichophyton erinacei. Data from various regions and hedgehog species are synthesised to assess the significance of pet hedgehogs as potential reservoirs and transmitters of zoonotic pathogens. Our study highlights the importance of understanding the health risks associated with pet hedgehogs and underscores the need for continued research to mitigate zoonotic disease transmission from these potentially disease-carrying companions.

Antifungal Resistance, Susceptibility Testing and Treatment of Recalcitrant Dermatophytosis Caused by Trichophyton indotineae: A North American Perspective on Management

There is an ongoing epidemic of chronic, relapsing dermatophytoses caused by Trichophyton indotineae that are unresponsive to one or multiple antifungal agents. Although this new species may have originated from the Indian subcontinent, there has been a notable increase of its reporting in other countries. Based on current literature, antifungal susceptibility testing (AFST) showed a large variation of terbinafine minimum inhibitory concentrations (MICs) (0.04 to ≥ 32 µg/ml). Elevated terbinafine MICs can be attributed to mutations in the squalene epoxidase gene (single mutations: Leu393Phe, Leu393Ser, Phe397Leu, and double mutations: Leu393Phe/Ala448Thr, Phe397Leu/Ala448Thr). Itraconazole MICs had a lower range when compared with that of terbinafine (0.008-16 µg/ml, with most MICs falling between 0.008 µg/ml and < 1 µg/ml). The interpretation of AFST results remains challenging due to protocol variations and a lack of established breakpoints. Adoption of molecular methods for resistance detection, coupled with AFST, may provide a better evaluation of the in vitro resistance status of T. indotineae. There is limited information on treatment options for patients with confirmed T. indotineae infections by molecular diagnosis; preliminary evidence generated from case reports and case series points to itraconazole as an effective treatment modality, while terbinafine and griseofulvin are generally not effective. For physicians working outside of endemic regions, there is currently an unmet need for standardized clinical trials to establish treatment guidelines; in particular, combination therapy of oral and topical agents (e.g., itraconazole and ciclopirox), as well as with other azoles (i.e., fluconazole, voriconazole, ketoconazole), warrants further investigation as multidrug resistance is a possibility for T. indotineae.

A Clinico-Mycological and Histopathological Study of Recurrent Dermatophytosis

Background

A few recent studies have shown fungal elements within the hair follicle epithelium, which may act as a reservoir and responsible for recurrent dermatophytosis.

Objectives

To assess the clinical patterns, mycological profile, and histopathology of recurrent dermatophytosis and to determine the prevalence of fungal hyphae in the hair follicle epithelium and other appendages.

Materials and Methods

One hundred and fifty clinically diagnosed cases of recurrent dermatophytic infection were included. Skin samples were taken for direct microscopy, fungal culture, and histopathological analysis. Haematoxylin and eosin and special staining with periodic acid Schiff (PAS) and Gomori's methenamine silver (GMS) were performed to detect the fungal hyphae in the skin and hair follicle epithelium.

Results

The most common clinical pattern observed was tinea corporis et cruris in 64 patients (42.66%). On direct microscopy and fungal culture, positive results were obtained in 116 cases (77.33%) and 78 (52%) cases, respectively. Presence of fungal hyphae in the stratum corneum, hair follicle, and acrosyringium was seen in 107 patients (71.33%), 47 patients (31.33%), and five patients (3.33%), respectively. Out of the 52 cases with hair follicle and eccrine gland involvement, history of fixed drug combinations (FDC) cream use was present in 42 cases (80.76%) and absent in ten cases (19.24%) (P = 0.000062).

Limitations

Skin samples were taken only from a single skin lesion. Higher incidence of follicular invasion may have been detected if multiple biopsy samples were taken.

Conclusion

Hair follicle/eccrine sweat gland involvement was observed in nearly one-third of the patients, which may act as a reservoir and may be responsible for recurrence and chronicity. Histopathology should be considered as an important adjuvant tool in recurrent dermatophytosis to establish the extent of the infection, which guides the further management.

Tinea universalis due to Trichophyton indotineae in an adult male

Tinea universalis is a condition when most of the anatomical sites of body are involved due to dermatophyte infection both in immunocompetent and immunocompromised individuals. Here we present a case of tinea universalis due to Trichophyton indotineae (T. indotineae) from India. This species has emerged recently. Earlier, it has been reported as Trichophyton mentagrophytes (T. mentagrophytes) and Trichophyton interdigitale (T. interdigitale). T. indotineae has been associated with outbreaks and epidemics of chronic, recalcitrant, and nonresponsive to terbinafine, in India and several other countries. The patient was prescribed Itraconazole (200 mg/day), Luliconazole cream topically and antihistamine at night, with marked improvement clinically. Easy availability and misuse of corticosteroids cream, as over-the-counter drug, should be discouraged.

Proposal for a Severity Score (DeASI, Dermatophytosis Area and Severity Index) for the Evaluation of Dermatophyte Infections - A Delphi Consensus Study

Background

There has been a significant increase in the incidence of recurrent, resistant, and extensive dermatophyte infections worldwide recently. This menace has spurred the need for more well-designed randomized controlled trials to optimize the treatment of dermatophyte skin infections. One of the limitations in designing such studies is the limited availability of standard and validated score, to measure the severity of dermatophyte infections.

Aims

To create a severity score for the evaluation of dermatophyte infections.

Materials and Methods

A Delphi consensus model was used to frame a severity scoring tool for superficial dermatophyte skin infections. Fourteen experts participated in the first round and twelve experts participated in the second round.

Results

Based on the expert consensus, a final scoring system proposed was: Final Severity Score (FSS) = Sum total of Body Surface Area (BSA) in hand units for each patch multiplied by the sum of the scores for pruritis (P), lichenification (L), and actively raised borders (A) for each patch (FSS = BSA in hand units × (P + E + L + A) of patch 1 + BSA in hand units × (P + E + A) of patch 2 …etc.). For measuring hand units more accurately fractional values of 0.25 can be used (0.25 corresponding to an approximate 1/4th of a hand unit). A score of +1 will be added in case of the following - 1) Close contact/family member affected, 2) History of at least one recurrence in the previous 6 months after a course of oral antifungals, 3) History of immunosuppression (on immunosuppressive medication or having underlying immunosuppressive disease). The scores will be valid only if the patient has not used any treatment topical or systemic, for at least 2 weeks before enrolment.

Conclusion

The proposed Dermatophytosis Area and Severity Index (DeASI) score will help the physicians and researchers standardize the treatment protocol for dermatophytosis, henceforth, assessing the response to therapy. This will also help to standardize the parameters of effectiveness while designing any clinical trial.

Dermatophyte resistance - on the rise

Dermatophytes are group of filamentous fungi which have adapted to living on the skin of humans and other animals. In the last decade, reports have emerged from Asia of new dermatophyte strains showing resistance to the commonly used antifungal agent terbinafine and others. The spread of these resistant strains has been noted in many other countries globally. Little is known about the mechanisms or management of this emerging problem. Urgent research and changes to current practice are required if the spread of the infection is to be contained and managed effectively.

The Epidemiology of Tinea Capitis in Guangxi Province, China

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.

The Domestic Isolation of Terbinafine- and Itraconazole-Resistant Trichophyton indotineae in Chinese Mainland

BACKGROUND

Trichophyton indotineae, a new species of dermatophytes, has become a significant concern in treating dermatophytosis due to the high level of terbinafine resistance reported in India and even worldwide.

OBJECTIVES

This study aimed to report the terbinafine- and itraconazole-resistant T. indotineae in Chinese mainland, by identifying the phylogenetic classification of the isolate strain, and detecting the drug resistance, gene mutation and expression.

PATIENTS/METHODS

The skin scales of the patient were cultured on SDA and the isolate was authenticated by DNA sequencing and MALDI-TOF MS. Antifungal susceptibility testing was performed following the M38-A2 CLSI protocol to examine the MICs values of terbinafine, itraconazole, fluconazole, etc. The strain was screened for mutations in the squalene epoxidase (SQLE) gene by Sanger sequencing and detected the expression of CYP51A and CYP51B by qRT-PCR.

RESULTS

A multi-resistant ITS genotype VIII sibling of the T. mentagrophytes complex (T. indotineae) was isolated in Chinese mainland. The strain harbored high terbinafine MIC of > 32 μg/mL and itraconazole MIC of 1.0 μg/mL, which was identified a mutation in the squalene epoxidase gene with amino acid substitution (Phe397Leu, mutation 1191C > A). In addition, overexpression of CYP51A and CYP51B was observed. With multiple relapses, the patient finally achieved clinical cure by itraconazole pulse therapy and topical clotrimazole cream for 5 weeks.

CONCLUSIONS

The first domestic strain of terbinafine- and itraconazole-resistant T. indotineae from a patient in Chinese mainland was isolated. Itraconazole pulse therapy can be an effective method for the treatment of T. indotineae.

Trichophyton indotineae, from epidemiology to therapeutic

Trichophyton indotineae is a newly described dermatophyte species. This fungal pathogen has recently emerged in India and is responsible for chronic or recurrent widespread superficial infections. Resistance to terbinafine is frequently associated to this pathogen and is related to point mutations in the gene encoding the squalene epoxidase. T. indotineae infections have been reported outside India, highlighting the risk of worldwide diffusion of this microorganism. Species identification and antifungal susceptibility determination are key points for infection control but still remain challenging. Systemic treatment is usually required and itraconazole is frequently prescribed in case of terbinafine resistance. This review summarizes main features of T. indotineae taxonomy, epidemiology, clinical manifestations, identification, antifungal profile, treatment and prevention.

Cutaneous Fungal Infections Caused by Dermatophytes and Non-Dermatophytes: An Updated Comprehensive Review of Epidemiology, Clinical Presentations, and Diagnostic Testing

Cutaneous fungal infection of the skin and nails poses a significant global public health challenge. Dermatophyte infection, mainly caused by Trichophyton spp., is the primary pathogenic agent responsible for skin, hair, and nail infections worldwide. The epidemiology of these infections varies depending on the geographic location and specific population. However, epidemiological pattern changes have occurred over the past decade. The widespread availability of antimicrobials has led to an increased risk of promoting resistant strains through inappropriate treatment. The escalating prevalence of resistant Trichophyton spp. infections in the past decade has raised serious healthcare concerns on a global scale. Non-dermatophyte infections, on the other hand, present even greater challenges in terms of treatment due to the high failure rate of antifungal therapy. These organisms primarily target the nails, feet, and hands. The diagnosis of cutaneous fungal infections relies on clinical presentation, laboratory investigations, and other ancillary tools available in an outpatient care setting. This review aims to present an updated and comprehensive analysis of the epidemiology, clinical manifestations, and diagnostic testing methods for cutaneous fungal infections caused by dermatophytes and non-dermatophytes. An accurate diagnosis is crucial for effective management and minimizing the risk of antifungal resistance.

Comprehensive Taxonomical Analysis of Trichophyton mentagrophytes/interdigitale Complex of Human and Animal Origin from India

Taxonomic delineation of etiologic agents responsible for recalcitrant dermatophytosis causing an epidemic in India is still debated. The organism responsible for this epidemic is designated as T. indotineae, a clonal offshoot of T. mentagrophytes. To evaluate the real identity of the agent causing this epidemic, we performed a multigene sequence analysis of Trichophyton species isolated from human and animal origin. We included Trichophyton species isolated from 213 human and six animal hosts. Internal transcribed spacer (ITS) (n = 219), translational elongation factors (TEF 1-α) (n = 40), ß-tubulin (BT) (n = 40), large ribosomal subunit (LSU) (n = 34), calmodulin (CAL) (n = 29), high mobility group (HMG) transcription factor gene (n = 17) and α-box gene (n = 17) were sequenced. Our sequences were compared with Trichophyton mentagrophytes species complex sequences in the NCBI database. Except for one isolate (ITS genotype III) from animal origin, all the tested genes grouped our isolates and belonged to the "Indian ITS genotype", currently labeled as T. indotineae. ITS and TEF 1-α were more congruent compared to other genes. In this study, for the first time, we isolated the T mentagrophytes ITS Type VIII from animal origin, suggesting the role of zoonotic transmission in the ongoing epidemic. Isolation of T. mentagrophytes type III only from animal indicates its niche among animals. Outdated/inaccurate naming for these dermatophytes in the public database has created confusion in using appropriate species designation.

Report of terbinafine resistant Trichophyton spp. in Italy: Clinical presentations, molecular identification, antifungal susceptibility testing and mutations in the squalene epoxidase gene

BACKGROUND

Numerous reports of resistance to terbinafine in Trichophyton spp. from all over the world are arousing justified attention and concern. Point mutations in the gene that encodes the squalene epoxidase (SQLE) enzyme are responsible for these therapeutic resistances.

OBJECTIVES

Primary objective of the study was to describe first isolates of Trichophyton spp. resistant to terbinafine among the patients treated between September 2019 and June 2022 at the Dermatology Units of Ospedale Maggiore Policlinico and San Bortolo Hospital. Secondary objective was to study the resistance mechanism.

METHODS

Patients with confirmed Trichophyton spp. infection has been treated with systemic and topical terbinafine. Patients were then re-evaluated 12 weeks after the therapy. Patients with incomplete or absent response to terbinafine underwent a new skin scraping for direct mycological examination, new identification of dermatophyte species from culture and MALDI-TOF, molecular species identification, antifungal susceptibility testing and molecular analysis of SQLE gene.

RESULTS

We identified five patients without clinical response to treatment with terbinafine. The DNA sequencing of the ITS region identified one Trichophyton rubrum and four Trichophyton indotineae. The T. rubrum strain showed minimum inhibitory concentration (MIC) (90% growth inhibition) of 4 mg/L for terbinafine. The four T. indotineae strains showed a MICs range of 0.25-4 mg/L for terbinafine. The analysis of the SQLE gene in the T. rubrum strain showed a nucleotide substitution generating a missense mutation (L393F). The SQLE gene sequencing in the T. indotineae strains showed a nucleotide substitution generating a missense mutation (F397L) in two strains, a nucleotide substitution L393S in one strain and a nucleotide substitution F415C in another strain.

CONCLUSIONS

We report the first cases of terbinafine-resistant Trichophyton isolates in the Italian population. Solid antifungal management programs will be needed to promote more responsible use of antimycotics and preserve their therapeutic efficacy to control antifungal resistance.

Potential Inhibitory Effect of Miltefosine against Terbinafine-Resistant Trichophyton indotineae

Several prolonged and significant outbreaks of dermatophytosis caused by Trichophyton indotineae, a new emerging terbinafine-resistant species, have been ongoing in India in recent years, and have since spread to various countries outside Asia. Miltefosine, an alkylphosphocholine, is the most recently approved drug for the treatment of both visceral and cutaneous leishmaniasis. Miltefosine in vitro activity against terbinafine-resistant and susceptible T. mentagrophytes/T. interdigitale species complex, including T. indotineae, is limited. The current study aimed to assess miltefosine's in vitro activity against dermatophyte isolates, which are the most common causes of dermatophytosis. Miltefosine, terbinafine, butenafine, tolnaftate, and itraconazole susceptibility testing was performed using Clinical and Laboratory Standards Institute broth microdilution methods (CLSI M38-A3) against 40 terbinafine-resistant T. indotineae isolates and 40 terbinafine-susceptible T. mentagrophytes/T. interdigitale species complex isolates. Miltefosine had MIC ranges of 0.063-0.5 µg/mL and 0.125-0.25 µg/mL against both terbinafine-resistant and susceptible isolates. In terbinafine-resistant isolates, the MIC₅₀ and MIC₉₀ were 0.125 µg/mL and 0.25 µg/mL, respectively, and 0.25 µg/mL in susceptible isolates. Miltefosine had statistically significant differences in MIC results when compared to other antifungal agents (p-value 0.05) in terbinafine-resistant strains. Accordingly, the findings suggest that miltefosine has a potential activity for treating infections caused by terbinafine-resistant T. indotineae. However, further studies are needed to determine how well this in vitro activity translates into in vivo efficacy.

Molecular epidemiology of Trichophyton infections among canines from Northern India

Dermatophytes are keratinophilic fungi that cause skin infections in both humans and animals. Recently, the incidence rates of fungal infections associated with Trichophyton spp. have been considered endemic in many locations. The aim of this study was to isolate and characterize Trichophyton spp. from canines and felines. In the present study, screened 442 canine (n = 386) and feline (n = 56) samples for dermatophytes. Among all the samples, ten isolates were identified as Trichophyton spp. based on micro-morphological features. For comparative analysis, we included three human strains of Trichophyton mentagrophytes complex. In vitro susceptibility of antifungal drugs indicated the highest sensitivity except for fluconazole. The canine and human strains were genetically characterized by sequencing three genes: the internal transcribed spacer region of rDNA, translation elongation factor 1- gene, and beta-tubulin. Based on sequence homology and phylogenetic analysis, the ten canine strains belonged to four different species/ genotypes such as T. mentagrophytes genotype VIII (T. indotineae) (n = 5), T. interdigitale (n = 2), T. simii (n = 2) and T. quinckeanum (n = 1). The three human strains used for comparative analysis were identified as T. mentagrophytes genotype VIII (n = 2) and T. benhamiae (n = 1). The study hence indicates that the T. mentagrophytes genotype VIII, considered as an endemic and emerging human pathogenic clone in India, is also the prevalent in animals.

First Terbinafine-Resistant Trichophyton indotineae Isolates with Phe397Leu and/or Thr414His Mutations in Turkey

Fungal infections of the skin, nails, and hair caused by dermatophyte species continue to be a worldwide concern. The increase in terbinafine-resistant superficial dermatophytosis has become a major concern over the last decade. In this report, we presented two cases of infection with terbinafine-resistant Trichophyton indotineae, the first diagnosis of this species in Turkey. One patient exhibited erythematous pruritic patches and plaques in the inguinal and gluteal regions, while the other patient showed annular erythematous scaly plaques in the bilateral posterior thigh and gluteal regions. One patient harbored a CD36 mutation. Both strains harbored the same amino acid substitution in the squalene epoxidase gene, whereas one isolate had another unknown mutation. Clinical improvement was observed with resveratrol treatment in the patient with the CD36 mutation but not in the other patient.

Antifungal stewardship: What we need to know

Antimicrobial stewardship refers to a well-coordinated program which promotes the scientific and rational use of antimicrobials, reduces the chances of drug resistance and improves patient outcomes. A comprehensive English language literature search was done across multiple databases (PubMed, EMBASE, MEDLINE and Cochrane) for the period 1990-2022, revealing a large volume of reports of growing resistance to established antifungal therapies, against a backdrop of irrational and unscientific prescriptions. As a result of this, antifungal stewardship, a new kid on the block, has recently garnered attention. This review article is an attempt to summarise the basic concept of stewardship programs, highlighting the dire need to implement the same in the present situation of antifungal resistance and treatment failure.

[Clinical picture, causative agents and diagnostics of dermatomycoses]

Dermatomycoses affect free skin, hairy scalp, fingernails and toenails. In addition, oral mucosa and genital mucosa can also be affected by fungal infections. The most common pathogens causing skin fungal infections are dermatophytes. They are responsible for, among others, tinea corporis, tinea capitis and onychomycosis (tinea unguium). Mainly anthropophilic dermatophytes are found as pathogens. In the case of tinea capitis-at least in Europe and in German-speaking countries-zoophilic skin fungi must also be considered. Rarely, geophilic dermatophytes can also be isolated. Yeast infections of the skin, mostly caused by Candida albicans, primarily affect the intertriginous skin areas, for example, the groin region, but also the submammary area and the spaces between the fingers and toes. Elderly patients are often affected, but also infants and, in particular, immunocompromised patients. These patient groups are also more frequently affected by oral mucosal infections caused by Candida albicans and other Candida species. Pseudomembranous candidiasis of the oral mucosa and tongue typically affects patients with HIV/AIDS. Mold infections in dermatology are relevant in onychomycosis of the big toenail. The causative agent is usually Scopulariopsis brevicaulis. Cutaneous mold infections are rare and only occur in immunocompromised patients. The mycological diagnosis of dermatomycoses is based on the microscopic, if possible fluorescence-optical detection of fungal hyphae and spores from skin scales, nail shavings and hair roots. The culture detection of dermatophytes, yeasts and molds allows the identification of the causative fungal species, but often fails, especially in patients who have already been treated with antifungal agents. In view of the high sensitivity and specificity of the molecular methods for fungal detection compared to culture, polymerase chain reaction (PCR) must realistically be regarded as the gold standard for dermatophytosis diagnostics. However, it should not be neglected that the three pillars of diagnostics-preparation, culture, PCR-currently deliver the best results.

Metagenomics of Toenail Onychomycosis in Three Victorian Regions of Australia

Onychomycosis is a fungal disease of the nail that is found worldwide and is difficult to diagnose accurately. This study used metagenomics to investigate the microbiology of 18 clinically diagnosed mycotic nails and two normal nails for fungi and bacteria using the ITS2 and 16S loci. Four mycotic nails were from Bass Coast, six from Melbourne Metropolitan and eight from Shepparton, Victoria, Australia. The mycotic nails were photographed and metagenomically analysed. The ITS2 sequences for T. rubrum and T. interdigitale/mentagrophytes averaged over 90% of hits in 14/18 nails. The high abundance of sequences of a single dermatophyte, compared to all other fungi in a single nail, made it the most likely infecting agents (MLIA). Trichophyton rubrum and T. interdigitale/mentagrophytes were found in Bass Coast and Shepparton while only T. interdigitale/mentagrophytes was found in Melbourne. Two nails with T. interdigitale/mentagrophytes mixed with high abundance non-dermatophyte moulds (NDMs) (Aspergillus versicolor, Acremonium sclerotigenum) were also observed. The two control nails contained chiefly Fusarium oxysporum and Malassezia slooffiae. For bacteria, Staphylococcus epidermidis was in every nail and was the most abundant, including the control nails, with an overall mean rate of 66.01%. Rothia koreensis, Corynebacterium tuberculostearicum, and Brevibacterium sediminis also featured.

Detection of emerging genotypes in Trichophyton mentagrophytes species complex: A proposal for handling biodiversity in dermatophytes

A resistant and hypervirulent dermatophyte from India has been described as a taxonomic novelty, Trichophyton indotineae, a species of the Trichophyton mentagrophytes complex. Rapid detection and correct identification of closely similar dermatophytes with different predilections are essential for efficient clinical management. We evaluated the efficacy of rapid diagnostic methods clinical and environmental strains in the T. mentagrophytes complex. The methods included Real-time-PCR, DermaGenius, LAMP, and MALDI-ToF MS, using rDNA ITS sequences as taxonomic standard. The results show that only MALDI-ToF MS can distinguish 96.97% T. indotineae from other closely related species. The complex comprises numerous clones which may differ in anonymous markers but with similar evolutionary behavior. Therefore, we recommend to distinguish species only when they show an appreciable degree of adaptation and thus are clinically significant. The distinction of remaining clonal diversity is an epidemiological query and can be solved by haplotype numbering.

Voriconazole is superior to combined itraconazole/isotretinoin therapy and itraconazole monotherapy in recalcitrant dermatophytosis

BACKGROUND

There has been an emergence of recalcitrant, recurrent, and difficult-to-treat tinea. Monotherapy with oral antifungals leads to partial clearance or high recurrence of lesions. Isotretinoin is a good adjuvant to systemic antifungals in chronic dermatophytosis. Voriconazole could be a future alternative due to its efficacy against dermatophytes and little resistance.

OBJECTIVE

To evaluate the efficacy and safety of oral itraconazole, combined itraconazole/isotretinoin therapy, and voriconazole for recalcitrant tinea.

PATIENTS AND METHODS

This study included 90 patients with chronic, recurrent, and/or recalcitrant tinea. They were equally divided into 3 groups: itraconazole monotherapy, combined itraconazole/isotretinoin therapy, and voriconazole monotherapy. All patients received treatments for 6 weeks. The clinical response was classified as either a complete or incomplete clinical cure. Potassium hydroxide microscopy and culture were performed to identify mycological cure. Patients with complete cure were followed up for another 6 months to detect any recurrence.

RESULTS

Complete clinical cure was observed in 53.3% of the itraconazole group, 70% of the itraconazole/isotretinoin group, and 83.3% of the voriconazole group. Mycological cure was detected in 56.7% of the itraconazole group, 83.3% of the itraconazole/isotretinoin group, and 86.7% of the voriconazole group. There was a statistically significant difference between the three groups in favor of voriconazole, then the combined group. No significant adverse effects were observed. The recurrence rate was significantly lower in the voriconazole group compared to the other two groups.

CONCLUSIONS

Voriconazole could be a future alternative for the treatment of recalcitrant dermatophytosis.

DNA-Chip-basierte Diagnose der Onychomykose und Tinea pedis

HINTERGRUND UND ZIELE

Onychomykose (OM) und Tinea pedis (TP) sind häufige Pilzinfektionen der Haut. Aktuell basiert die Diagnose vornehmlich auf mikroskopischem Direktnachweis und/oder Kultur. Beide Methoden haben jedoch eine geringe bis mäßige Sensitivität und benötigen teilweise mehrere Wochen, bis endgültige Laborergebnisse vorliegen. Um die Diagnose kutaner Pilzinfektionen zu verbessern, wurden PCR-basierte Methoden entwickelt. Hier haben wir hier die Sensitivität und Spezifität einer Chip-basierten Multiplex-PCR mit mikroskopischen Direktnachweis und verglichen.

PATIENTEN UND METHODIK

In einer monozentrischen, prospektiven Studie wurden bei Patienten mit Verdacht auf OM (n  =  67) oder TP (n  =  73) Schuppenpräparate entnommen und mittels mikroskopischem Direktnachweis, Kultur und DNA-Chip-Technologie der Erregernachweis durchgeführt. In einem weiteren Ansatz wurde überprüft, ob Abstriche als Alternative zur Entnahme eines Schuppenpräparates verwendet werden können. Hierfür wurden 24 weitere OM/TP-Patienten rekrutiert und die Ergebnisse der DNA-Chip-Technologie aus Abstrichen mit denen aus den Schuppenpräparaten verglichen.

ERGEBNISSE

Im Vergleich aller Methoden hatte die DNA-Chip-Technologie die höchste Sensitivität, eine Kombination von DNA-Chip-Technologie mit mikroskopischem Direktnachweis erhöhte dies weiter. Ergebnisse dieser kombinierten Labordiagnostik sind innerhalb von 24 Stunden verfügbar. Der Vergleich der Probenentnahmetechniken (Abstrich beziehungsweise Schuppenpräparat) zeigte vergleichbare Ergebnisse.

SCHLUSSFOLGERUNGEN

Die molekulare Diagnostik (mittels DNA-Chip-Technologie) hat eine hohe Sensitivität für die OM- und TP-Diagnostik, insbesondere in Kombination mit dem mikroskopischen Direktnachweis.

The emergence of Trichophyton indotineae: Implications for clinical practice

Emergence and increase of terbinafine-resistant dermatophytosis led to the identification of Trichophyton mentagrophytes internal transcriber space (ITS) genotype VIII in 2017, later renamed as Trichophyton indotineae and classified as a separate species in 2020. With its suspected origin in South Asia, this novel strain has emerged in Bahrain, Canada, Denmark, Finland, France, Germany, India, Iran, Japan, Russia, and Switzerland, with its spread attributed primarily to travel and migration. Diagnosis using routine mycology laboratory techniques is unable to distinguish T. indotineae from T. mentagrophytes and T. interdigitale; specific identification requires genomic sequencing to identify unique, specific markers. One speculated reason for this recent outbreak is the unrestricted use of topical steroid creams and antifungal agents. Patients with extensive tinea corporis and cruris due to T. indotineae present with inflammatory red plaques in multiple body sites. The majority of these infections prove to be resistant to conventional antifungals, including allylamines and azoles (itraconazole and fluconazole), thus emphasizing the need for antifungal susceptibility testing before treatment initiation and for reassessing in nonresponsive patients. Molecular studies have identified several point mutations in the ERG1 (terbinafine resistance) and ERG11 (azole resistance) genes, which need to be analyzed further. Use of relatively new agents, such as voriconazole and luliconazole, as well as device modalities and combination therapy, could be investigated for recalcitrant T. indotineae infections.

Trichophyton indotineae—An Emerging Pathogen Causing Recalcitrant Dermatophytoses in India and Worldwide—A Multidimensional Perspective

Trichophyton (T.) indotineae is a newly identified dermatophyte species that has been found in a near-epidemic form on the Indian subcontinent. There is evidence of its spread from the Indian subcontinent to a number of countries worldwide. The fungus is identical to genotype VIII within the T. mentagrophytes/T. interdigitale species complex, which was described in 2019 by sequencing the Internal Transcribed Spacer (ITS) region of ribosomal DNA of the dermatophyte. More than 10 ITS genotypes of T. interdigitale and T. mentagrophytes can now be identified. T. indotineae causes inflammatory and itchy, often widespread, dermatophytosis affecting the groins, gluteal region, trunk, and face. Patients of all ages and genders are affected. The new species has largely displaced other previously prevalent dermatophytes on the Indian subcontinent. T. indotineae has become a problematic dermatophyte due to its predominantly in vitro genetic resistance to terbinafine owing to point mutations of the squalene epoxidase gene. It also displays in vivo resistance to terbinafine. The most efficacious drug currently available for this terbinafine-resistant dermatophytoses, based on sound evidence, is itraconazole.

Characterization of Recalcitrant Dermatophytosis in a Multicenter Study in Sri Lanka

A changing clinical scenario of dermatophytosis has been observed in Sri Lanka during the past few years. In keeping with the trend described in India, an increase in the number of chronic, relapsing, and recalcitrant infections has been noted. The objective of our study was to assess the therapeutic response of dermatophytosis to standard antifungal treatment in Sri Lanka and to identify possible contributory factors in cases showing inadequate therapeutic response. A descriptive, observational, cross-sectional study was carried out in nine hospitals, representing each province. Over 6 months, patients with dermatophytosis on glabrous skin were included. All subjects underwent skin scrapings for mycological studies and were treated with a standard course of antifungals for a specific period. In those patients who achieved complete clearance, recurrences were noted. The study included 796 patients, of whom 191 (24%) had symptoms for more than 3 months at presentation. A total of 519 patients (65.2%) had multiple-site involvement, and 503 (63.2%) had evidence of prior use of topical steroids. Skin scrapings were positive for fungal elements in the direct smears of 659 patients (82.8%), and the predominant dermatophyte isolated was Trichophyton mentagrophytes (65.6%). Partial responders after 10 weeks of treatment and recurrences after complete clearance were significantly greater in the group that used topical steroids before presentation (P < 0.001). This study highlights the magnitude of the threat of an inadequate therapeutic response in dermatophytosis in Sri Lanka, and identifies steroid misuse, and the shift of the predominant fungal species to T. mentagrophytes as possible causative factors.

Comparative evaluation of host immune response and cytokine signature pertaining to Th1 and Th2 immune arms in serum and tissue among patients of acute localised vs. chronic disseminated dermatophytosis

BACKGROUND

India is witnessing an epidemic of dermatophytosis. The role of host immune response against fungi in chronicity and dissemination is topic of ongoing research. We conducted cross-sectional comparative study to determine the difference in Th1 (IFN-γ) and Th2 (IL4) response in serum and tissue between acute and localised vs. chronic and disseminated cases.

METHODS

Patients (18-60 years) were divided in two groups-group A (n = 114, BSA <5%, single anatomic site, duration <6 months, n = 118) and group B (n = 107 BSA >10%, > one anatomic site, duration >12 months, n = 118). Clinical parameters along with serum levels of IgE, IL-4 and IFN-γ and expression of IL4 and IFN-γ in dermal infiltrate were compared between group.

RESULTS

Trichophyton mentagrophytes complex was commonest causative fungi. Serum levels of IgE were significantly higher (median A-539.2, B-2901.0, p < .001) whereas levels IL-4(median A-21.3, B-20.4, p < .001) and IFN-γ(median A-9.6, B-5.1, p < .001) were significantly lower in chronic cases. Expression of IL-4 was observed in most biopsy specimens in both groups without any difference in intensity of staining. Expression of IFN-γ was not detected in all but one specimen across both the groups. Severe itching (OR:0.050, CI:0.018, 0.139, p < .001), sign of topical steroid abuse (OR:0.203,CI:0.077, 0.537; p = .001), ↓IFN-γ (OR:4.683, CI:1.634, 13.418; p = .004) correlated significantly and independently with chronic dermatophytosis.

CONCLUSION

Our study shows chronic and disseminated cases of dermatophytosis differ immunologically in terms of higher IgE, and lower IL4 and IFN-γ. Expression of IL4 is present in tissue of both acute, localised and chronic disseminated cases. Expression of IFN-γ cannot be established in our study.

Emerging Animal-Associated Fungal Diseases

The Global Action Fund for Fungal Infections (GAFFI) estimates that fungal diseases kill around 150 people each hour, and yet they are globally overlooked and neglected. Histoplasma and Talaromyces, which are associated with wildlife, cause systemic infections that are often lethal in patients with impaired cellular immunity. Dermatophytes that cause outbreaks in human hosts are often associated with domesticated animals. Changes in human behavior have been identified as a main cause of the emergence of animal-associated fungal diseases in humans, sometimes caused by the disturbance of natural habitats. An understanding of ecology and the transmission modes of causative agents is therefore essential. Here, we focus on fungal diseases contracted from wildlife and domesticated animals, their habitats, feces and carcasses. We discuss some basic fungal lifestyles and the risk of transmission to humans and illustrate these with examples from emerging and established diseases.

Simultaneous Delivery of Econazole, Terbinafine and Amorolfine with Improved Cutaneous Bioavailability: A Novel Micelle-Based Antifungal “Tri-Therapy”

Lack of accurate diagnosis and the use of formulations designed to address the poor aqueous solubility of antifungal agents, but not optimized for delivery, contribute to unsatisfactory outcomes for topical treatment of cutaneous mycoses. The objective of this study was to develop a micelle-based antifungal formulation containing econazole (ECZ), terbinafine (TBF) and amorolfine (AMF) using D-α-tocopheryl polyethylene glycol succinate (TPGS) for simultaneous cutaneous delivery of three agents with complementary mechanisms of action. The antifungal “tri-therapy” micelle-based formulation containing 0.1% ECZ, 0.1% TBF and 0.025% AMF had a drug loading 10-fold lower than the “reference” marketed formulations (Pevaryl^®, 1% ECZ; Lamisil^®, 1% TBF; Loceryl^®, 0.25% AMF). Finite dose application of the micelle-based formulation for 6 h resulted in a statistically equivalent deposition of ECZ (p > 0.05) and TBF (p > 0.05) from the 2 systems, and a 2-fold higher accumulation of AMF (p = 0.017). Antifungal concentrations above MIC₈₀ against Trichophyton rubrum were achieved in each skin layer with the “tri-therapy”, which also exhibited a preferential deposition of each antifungal agent in pilosebaceous unit (PSU)-containing biopsies as compared with PSU-free biopsies (p < 0.05). A planned clinical study will test whether these promising results translate to improved therapeutic outcomes in vivo.

Investigations upon the Improvement of Dermatophyte Identification Using an Online Mass Spectrometry Application

Online MALDI-TOF mass spectrometry applications, such as MSI-2, have been shown to help identify dermatophytes, but recurrent errors are still observed between phylogenetically close species. The objective of this study was to assess different approaches to reduce the occurrence of such errors by adding new reference spectra to the MSI-2 application. Nine libraries were set up, comprising an increasing number of spectra obtained from reference strains that were submitted to various culture durations on two distinct culture media: Sabouraud gentamicin chloramphenicol medium and IDFP Conidia medium. The final library included spectra from 111 strains of 20 species obtained from cultures on both media collected every three days after the appearance of the colony. The performance of each library was then analyzed using a cross-validation approach. The spectra acquisitions were carried out using a Microflex Bruker spectrometer. Diversifying the references and adding spectra from various culture media and culture durations improved identification performance. The percentage of correct identification at the species level rose from 63.4 to 91.7% when combining all approaches. Nevertheless, residual confusion between close species, such as Trichophyton rubrum, Trichophyton violaceum and Trichophyton soudanense, remained. To distinguish between these species, mass spectrometry identification should take into account basic morphological and/or clinico-epidemiological features.

The epidemic of the multiresistant dermatophyte Trichophyton indotineae has reached China

Due to its high degree of natural resistance to terbinafine in vitro and its tendency to spread globally from the Indian subcontinent, the emerging dermatophyte Trichophyton indotineae has become a major concern in dermatology. Herein, we present the first report of T. indotineae from mainland China. The transmission of the fungus to Guizhou Province in central China and eventual host susceptibilities were investigated. We studied 31 strains of the T. mentagrophytes complex from outpatient clinics of our hospital collected during the past 5 years. The set comprised four ITS genotypes, two of which were T. mentagrophytes genotype VIII, now known as Trichophyton indotineae; the earliest isolation in the Guiyang area appeared to date back to 2018. The isolate was derived from an Indian patient, while local Chinese patients had no dermatophytosis caused by this genotype. Reports from around the world indicated that almost all of the globally reported T. indotineae cases originated from the Indian subcontinent and surrounding countries without transmission among native populations, suggesting deviating local conditions or racial differences in immunity against this fungus.