An Outbreak of Trichophyton quinckeanum Zoonotic Infections in the Czech Republic Transmitted from Cats and Dogs

Severe kerion Celsi caused by Trichophyton quinckeanum: Severe kerion Celsi due to Trichophyton quinckeanum

We report a severe case of kerion Celsi of the scalp in a previously healthy 13-year-old girl due to Trichophyton quinckeanum, an emerging dermatophyte species in Europe. The species was definitely identified by DNA sequencing and the patient was successfully treated by oral terbinafine for 6 weeks. Kerion Celsi is a severe inflammatory form of tinea capitis, which is characterised by a purulent discharge and alopecia [1]. It typically occurs in children infected with zoophilic dermatophytes, such as Trichophyton mentagrophytes, and an increasing number of cases caused by other Trichophyton species has recently been reported [2]. Herein we report a severe case of kerion Celsi of the scalp caused by the emerging species Trichophyton quinckeanum, which was successfully treated by oral antifungal.

Terbinafine resistance in Trichophyton mentagrophytes and Trichophyton rubrum in the Czech Republic: A prospective multicentric study

BACKGROUND

Terbinafine, an allylamine antifungal, is crucial for treating dermatophytosis by inhibiting squalene epoxidase (SQLE) in the ergosterol biosynthetic pathway. However, resistance is emerging, particularly in India and Southeast Asia, but reports of resistance spread worldwide. Despite this, comprehensive studies on terbinafine resistance in Trichophyton are still limited.

OBJECTIVES

This research aimed to determine the prevalence of terbinafine resistance in the Czech Republic, with a focus on Trichophyton rubrum and Trichophyton mentagrophytes, and investigate the underlying molecular mechanisms.

PATIENTS/METHODS

A total of 514 clinical strains of T. rubrum and 240 T. mentagrophytes collected from four Czech clinical institutions were screened for terbinafine resistance. Molecular investigations included DNA sequencing, specifically the ITS rDNA region and SQLE gene, as well as antifungal susceptibility testing following EUCAST guidelines.

RESULTS

While no resistance was observed in T. rubrum, 2.5% of T. mentagrophytes strains exhibited resistance, marked by the F397L mutation in SQLE. Notably, resistance surged from 1.2% in 2019 to 9.3% in 2020 but reverted to 0% in 2021. All resistant strains were identified as T. mentagrophytes var. indotineae. Resistant strains exhibited high MICs for terbinafine (≥4 mg L-1 ) but low MICs to the other seven antifungals tested except for fluconazole.

CONCLUSIONS

This study highlights the emergence of terbinafine-resistant T. mentagrophytes strains in the Czech Republic, with the F397L mutation being pivotal. Due to the relatively low resistance level, the current guidelines for dermatomycosis treatment in the Czech Republic remain effective, but ongoing surveillance is essential for timely adaptations if resistance patterns change.

A New Genotype of Trichophyton quinckeanum with Point Mutations in Erg11A Encoding Sterol 14-α Demethylase Exhibits Increased Itraconazole Resistance

Trichophyton quinckeanum, the causative agent of mouse favus, has been responsible for several infections of animal owners in recent years and showed an infection peak around 2020 in Jena, Thuringia. The isolated T. quinckeanum strains from Thuringia differ in some positions of the ITS region compared to strains from the IHEM collection as well as to Trichophyton schoenleinii. All T. quinckeanum strains of the new genotype show up to a 100-fold increased itraconazole resistance as measured by microplate laser nephelometry (MLN) assays. Analysis of genes involved in Trichophyton indotineae azole resistance, such as Erg1, which encodes squalene epoxidase, and Erg11B, one of two copies of the sterol 14-α demethylase gene, show a 100% identity between the two T. quinckeanum genotypes. In contrast, Erg11A fragments differ in 15-nucleotide positions between both T. quinckeanum genotypes, resulting in the unique amino acid substitution Ala256Ser in resistant strains. The new T. quinckeanum genotype may have evolved through interspecies mating. Mating type analysis showed a nearly 100% identity of the minus type MAT1-1-1 fragment for all T. quinckeanum isolates. The closely related Trichophyton schoenleinii belongs to the plus mating type and has 100% identical fragments of Erg1 and Erg11B. Erg11A protein sequences of T. schoenleinii and T. quinckeanum showed increased diversity.

[Zoophilic dermatophytes during coronavirus pandemic in Germany]

During the coronavirus pandemic, significantly more pets were probably bought and kept. This study focuses on whether more zoophilic dermatophytes have subsequently been isolated and which species predominate. In the 1‑year period from March 2020 through February 2021, all zoophilic dermatophytes from all submissions to the Mölbis laboratory were recorded. Both the cultural and the molecular evidence of fungal detection from skin scrapings, hair roots, and, in single cases, from nails, were considered. For dermatophyte DNA (Deoxyribonucleic acid) detection, an in-house polymerase chain reaction (PCR) - enzyme-linked immunosorbent assay (ELISA) was used. In distinct cases, identification of dermatophytes was confirmed by sequencing of the internal transcribed spacer (ITS) region of the rDNA, and of the gene of the translation elongation factor (TEF)-1α. In 579 (2.56%) of 22,575 samples studied in the year 2020/2021, zoophilic dermatophytes were detectable with PCR-ELISA and/or by cultivation. In comparison, the proportion of zoophilic dermatophytes was 2.03% in the 1‑year period 2014/2015, and only 1.6% in 2018/2019. The 579 zoophilic dermatophytes were identified as follows: Trichophyton (T.) benhamiae 186 (32.1%), T. mentagrophytes 173 (29.9%), T. quinckeanum 110 (19.0%), Microsporum (M.) canis 78 (13.5%), T. verrucosum 22 (3.8%), Nannizzia (N.) persicolor 8 (1.4%), T. erinacei 1 (0.2%), and T. equinum 1 (0.2%). T. benhamiae had the highest prevalence from June to September 2020, then again in December. T. quinckeanum is associated with a sharp increase in the mice population in Germany in 2020; a significant increase was found in the months September 2020 to January 2021. T. mentagrophytes had a conspicuous peak in September. Compered with that M. canis in November. Up to 50% of the dermatophytoses caused by T. mentagrophytes, T. quinckeanum, and M. canis affected children and adolescents, while in the case of T. benhamiae it was as much as two thirds. Tinea corporis was the most common, followed by tinea faciei and tinea capitis. M. canis infections affected the capillitium more frequently than the face. Zoophilic dermatophytes were increasingly isolated during the coronavirus pandemic in Germany when compared to previous year periods. In first place, the dermatophyte T. benhamiae from guinea pigs was found in children and adolescents. A significant proportion of dermatophytoses concerned adults. T. quinckeanum is an emerging pathogen in Germany with unprecedented high infection rates in 2020.

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.

Descriptive epidemiology of dermatophytosis in rodents

INTRODUCTION

Dermatophytosis is a zoonotic disease caused by a group of keratinophilic fungi called dermatophytes.

OBJECTIVES

Since the epidemiology of diseases revolves over time, this research studies the incidence of dermatophytosis among rodents referred to mycology laboratory during 2019-2021.

METHODS

A total of 163 rodents including rabbits, guinea pigs, and hamsters suspecting having dermatophytosis were sampled by scraping lesions. Direct microscopic examination, culture, and polymerase chain reaction were done for diagnosis of dermatophytosis and identification of the etiologic agent.

RESULTS

The results of this study showed that 37.4% of rodents were involved with dermatophytosis, among which 41.13% of rabbits, 25% of guinea pigs, and 26.3% of hamsters were included. Microsporum canis (52.7%) was the most isolated agent. Incidence of dermatophytosis was higher in female in rabbits while in hamsters and guinea pigs male were mostly infected. Rodents less than 6 months were more susceptible for dermatophytosis except for hamsters in which 6-12 months animals had a higher prevalence.

CONCLUSION

In conclusion, it is significant to update our knowledge about the epidemiology of dermatophytosis in rodents and other animals every few years to define valid preventive strategies. Moreover, since dermatophytes are contagious and zoonotic, it is also a priority to apply preventing methods for dermatophytosis and treat infected rodents with appropriate antifungal agents to decrease the risk of infection.

First report of tinea corporis caused by Trichophyton quinckeanum in Iran and its antifungal susceptibility profile

Background and Purpose

Trichophyton quinckeanum, a known zoophilic dermatophyte responsible for favus form in rodents and camels, is occasionally reported to cause human infections.

Case Report

This study aimed to report a case of tinea corporis caused by T. quinckeanum that experienced annular erythematous pruritic plaque with abundant purulent secretions. In June 2021, a 15-year-old girl with an erythematous cup shape lesion on the right wrist bigger than 3 cm in diameter was examined for tinea corporis. Since March, 2016 her family has kept several camels at home. Direct examination of skin scraping and purulent exudates revealed branching septal hyaline hyphae and arthrospore. Morphological evaluation of the recovered isolate from the culture and sequencing of ITS1-5.8S rDNA-ITS2 region resulted in the identification of T. quinckeanum. Antifungal susceptibility testing showed that this isolate had low minimum inhibitory concentration (MIC) values for luliconazole, terbinafine, and tolnaftate, but high MICs to itraconazole, fluconazole, posaconazole, miconazole, isavuconazole, ketoconazole, clotrimazole, and griseofulvin. However, the patient was successfully treated with oral terbinafine and topical ketoconazole.

Conclusion

It can be said that T. quinckeanum is often missed or misidentified due to its morphological similarity to T. mentagrophytes/T. interdigitale or other similar species. This dermatophyte species is first reported as the cause of tinea corporis in Iran. As expected, a few months after our study, T. quinckeanum was detected in other areas of Iran, in a few cases.

Laboratory Diagnosis and In Vitro Antifungal Susceptibility of Trichophyton quinckeanum from Human Zoonoses and Cats

The "One Health" concept increasingly demonstrates the global spread of pathogenic (also eukaryotic) microorganisms and their zoonotic potential. Dermatophytes can cause superficial mycoses in humans and animals. Furthermore, the number of transmissions from asymptomatic carriers to humans has been on the rise over the last few years. This study was focused on the detailed characterisation of clinical isolates of Trichophyton quinckeanum with epidemiological analyses and characterisation of their in vitro antifungal susceptibility patterns. The isolated dermatophytes were identified with a combination of conventional and molecular methods. In turn, their susceptibility in vitro was tested according to the Clinical and Laboratory Standards Institute (CLSI) M38 ed.3 protocol. A total of 36 strains were isolated, with 21 cases of T. quinckeanum zoonoses resulting from direct contact with symptomatic cats (58.3%). The other 15 strains (41.7%) were isolated simultaneously from healthy cats and their owners. All strains showed high susceptibility to allylamine, pyridinone, and phenyl morpholine derivatives but were resistant to fluconazole and ketoconazole. In conclusion, our study shows the frequency of zoonoses contracted from asymptomatic cats. Moreover, the antifungal susceptibility profiles indicate the serious risk posed to animal owners by resistant strains of T. quinckeanum, which are often responsible for recalcitrant-to-treatment cases.

Re-discovery of Trichophyton bullosum in North Africa as a cause of severe dermatophytosis in donkeys

This article reports the first verified cases of infection by Trichophyton bullosum in Africa since the description of the fungus, isolated in 1933 from the coat of horses in Tunisia and Mali. We found the fungus in cutaneous samples obtained from donkeys suffering from severe dermatitis with areas of alopecia and scaling in the surroundings of Cairo (Egypt). Fungal elements (arthroconidia and hyphae) were seen at the microscopy of material collected by skin scraping and digested in NaOH. Fungal colonies grown on various culture media were identified through PCR and sequencing of the ITS rDNA region. Since the original report in Africa and the Middle East, only a few cases have been reported thus far in humans in France and two cases in horses in the Czech Republic and Japan. Trichophyton bullosum seems thus an infrequent cause of dermatophytosis. However, the actual prevalence of this pathogen may be underestimated due to the similarity with T. verrucosum, a predominant cause of infection in cattle, occasionally found on horses and donkeys. Indeed, the two fungi can be distinguished only via molecular methods, which are poorly employed in epidemiological studies on equine and bovine dermatophytosis. The present study results add to our knowledge on the ecology of this poorly explored dermatophyte, supporting the concept that equines are the primary hosts of T. bullosum and confirming the presence of this pathogen in Africa. At the same time, these are the first unequivocally documented infections in donkeys due to T. bullosum.