Outbreaks And Epidemics Of Superficial Dermatophytosis Due To Trichophyton mentagrophytes Complex And Microsporum canis: Global And Indian Scenario

Studies on the in vitro mechanism and in vivo therapeutic effect of the antimicrobial peptide ACP5 against Trichophyton mentagrophytes

Trichophyton mentagrophytes is a zoophilic dermatophyte that can cause dermatophytosis in humans and animals. Antimicrobial peptides (AMPs) are considered as a promising agent to overcome the drug-resistance of T. mentagrophytes. Our findings suggest that cationic antimicrobial peptide (ACP5) not only possesses stronger activity against T. mentagrophytes than fluconazole, but also shows lower toxicity to L929 mouse fibroblast cells than terbinafine. Notably, its resistance development rate after resistance induction was lower than terbinafine. The present study aimed to evaluate the fungicidal mechanism of ACP5 in vitro and its potential to treat dermatophyte infections in vivo. ACP5 at 1 ×MIC completely inhibited T. mentagrophytes spore germination in vitro. ACP5 severely disrupts the mycelial morphology, leading to mycelial rupture. Mechanistically, ACP5 induces excessive ROS production, damaging the integrity of the cell membrane and decreasing the mitochondrial membrane potential, causing irreversible damage in T. mentagrophytes. Furthermore, 1% ACP5 showed similar efficacy to the commercially available drug 1% terbinafine in a guinea pig dermatophytosis model, and the complete eradication of T. mentagrophytes from the skin by ACP5 was verified by tissue section observation. These results indicate that ACP5 is a promising candidate for the development of new agent to combat dermatophyte resistance.

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.

Retrospective Analysis of Tinea Capitis in Xinjiang, China

Tinea capitis is a cutaneous infection of dermatophytes and predominant in children. It is one of common infectious diseases of children in Xinjiang, particularly in the southern Xinjiang. The aim of this study is to analyze the clinical and mycological characteristics of patients with tinea capitis in Xinjiang China. Medical records from 2010 to 2021, Mycology Laboratory Department of Dermatology in the First Affiliated Hospital of Xinjiang Medical University, retrospectively investigated the clinical and mycological characteristics of 198 patients with tinea capitis. Hairs have been obtained for fungal examination, and analysis with 20% KOH and Fungus Fluorescence Staining Solution has been conducted. Identification of fungi was using of morphological and molecular biological methods. Among total number of 198 patients, 189 (96%) were children with tinea capitis, of which 119 (63%) were male and 70 (37%) were female; 9 (4%) were adult patients with tinea capitis, of which 7 were female and 2 were male. Preschool children between the ages of 3 and 5 years had the highest distribution (54%), followed by those between the ages of 6 and 12 years (33%), the ages under 2 years (11%) and the ages of 13-15 years (2%) respectively. Among all patients, 135 (68.18%) were Uygur, 53 (26.77%) were Han, 5 (2.53%) were Kazak, 3 (1.52%) were Hui, 1 (0.5%) was Mongolian and nationality information of 1 patient (0.5%) is unknown. The indentification results of the isolates showed that 195 (98%) patients had single-species infections and 3 (2%) patients had double mixed infections. Among single-species infection patients, Microsporum canis (n = 82, 42.05%), Microsporum ferrugineum (n = 56, 28.72%) and Trichophyton mentagrophytes (n = 22, 11.28%) were the most prevalent species. Other dermatophytes included Trichophyton tonsurans (n = 12, 6.15%), Trichophyton violaceum (n = 10, 5.13%), Trichophyton schoenleinii (n = 9, 4.62%) and Trichophyton verrucosum (n = 4, 2.05%). Among 3 cases of mixed infections, 1 was M. canis + T. tonsurans (n = 1), and the other 2 were M.canis + T.mentagrophytes (n = 2). In conclusion, the majority of tinea capitis patients in Xinjiang, China are Uygur male children aged 3-5 years. M. canis was the most prevalent species causing tinea capitis in Xinjiang. These results provide useful information for the treatment and prevention of tinea capitis.

Dermatophytosis caused by trichophyton mentagrophytes complex in organic pigs

BACKGROUND

Dermatophytosis (ringworm) caused by members of the Trichophyton mentagrophytes complex is rarely diagnosed in pigs but has been recognized as an increasingly common infection in humans. Further, resistance to antifungal drugs have been reported both in Asia and in Europe. This is the first scientific report of infection by the T. mentagrophytes complex in pigs in the Nordic countries.

CASE PRESENTATION

Skin lesions developed in grower pigs in an organic fattening pig farm with outdoor production and following laboratory analyses, dermatophytosis caused by members of the T. mentagrophytes complex was diagnosed. Infection was linked to poor hygiene, high humidity, and moderate outdoor temperatures, in combination with high pig density. A farm worker developed a skin lesion after close contact with affected pigs, which highlighted the zoonotic potential of porcine dermatophytosis. The dermatophytes may have originated from the herd supplying the growers where similar lesions occurred in pigs. Further, pigs from another organic fattening herd that received growers from the same supplier herd also developed dermatophytosis. The lesions healed without treatment as the housing conditions were improved. Isolation of affected pigs prevented spread to other pigs CONCLUSION: Members of the T. mentagrophytes complex can cause ringworm in pigs. The fungi probably persist in the haircoat and may cause overt disease when environmental conditions promote growth of mycelia.

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.

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.

Invasive Microsporum canis infection as a presenting complaint of late-diagnosed HIV infection

A 43-year-old male barber presented with 1 year history of a painful, itchy plaque on the dorsal hand. Microsporum canis was recovered from pus of the lesion. Serologic testing for human immunodeficiency virus (HIV) antibody was positive, with a CD4⁺ count of 81 cells per cubic millimeter. Invasive cutaneous Microsporum canis infection is uncommon and can be suggestive of HIV infection or other conditions of immunocompromise.

Antifungal resistance in Superficial mycoses

BACKGROUND AND OBJECTIVE

With the widespread use of antifungals to treat superficial mycoses, reports of antifungal resistance are increasing. Antifungal resistance is becoming a public health challenge and needs to be addressed in parallel with antibacterial and antiviral resistance.

METHODS

We review the growing resistance of fungal pathogens such as Trichophyton species and the emergence of novel pathogens, including multidrug-resistant strains in superficial mycoses. We also discuss the importance of laboratory diagnosis and antifungal susceptibility testing (AFST) in the management of recalcitrant infections.

RESULTS AND CONCLUSION

Antifungal resistance can occur naturally or develop over time when fungi are exposed to antifungals. The frequency of terbinafine-resistant Trichophyton isolates is increasing. Opportunistic pathogens such as Aspergillus and Candida species have developed resistance to classic azoles such as itraconazole and fluconazole, and the newer azoles such as posaconazole and voriconazole. Although uncommon, topical antifungals such as efinaconazole and tavaborole have shown to induce resistance in Trichophyton rubrum. The emergence of multidrug-resistant Trichophyton mentagrophytes/interdigitale, Candida auris, and Aspergillus species causing severe infections is highly concerning. Routine AFST should be considered to determine the most effective treatment, especially if there is failure to therapy. Combination treatment of oral and topical antifungals may be a consideration for managing recalcitrant infections.

Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry: Protocol standardisation, comparison and database expansion for faster and reliable identification of dermatophytes

BACKGROUND

Accurate and early identification of dermatophytes enables prompt antifungal therapy. However, phenotypic and molecular identification methods are time-consuming. MALDI-TOF MS-based identification is rapid, but an optimum protocol is not available.

OBJECTIVES

To develop and validate an optimum protein extraction protocol for the efficient and accurate identification of dermatophytes by MALDI-TOF MS.

MATERIALS/METHODS

Trichophyton mentagrophytes complex (n = 4), T. rubrum (n = 4) and Microsporum gypseum (n = 4) were used for the optimisation of protein extraction protocols. Thirteen different methods were evaluated. A total of 125 DNA sequence confirmed clinical isolates of dermatophytes were used to create and expand the existing database. The accuracy of the created database was checked by visual inspection of MALDI spectra, MSP dendrogram and composite correlation index matrix analysis. The protocol was validated further using 234 isolates.

RESULT

Among 13 protein extraction methods, six correctly identified dermatophytes but with a low log score (≤1.0). The modified extraction protocol developed provided an elevated log score of 1.6. Significant log score difference was observed between the modified protocol and other existing protocols (T. mentagrophytes complex: 1.6 vs. 0.2-1.0, p < .001; T. rubrum: 1.6 vs. 0.4-1.0, p < .001; M. gypseum:1.6 vs. 0.2-1.0, p < .001). Expansion of the database enabled the identification of all 234 isolates (73.5% with log score ≥2.0 and 26.4% with log scores range: 1.75-1.99). The results were comparable to DNA sequence-based identification.

CONCLUSION

MALDI-TOF MS with an updated database and efficient protein extraction protocol developed in this study can identify dermatophytes accurately and also reduce the time for identifying them.

A Household Microsporum canis Dermatophytosis Suggested by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry Analysis

Case series

Patients: Female, 4-year-old • her family (father, mother, sister)

Final Diagnosis: Microsporum canis dermatophytosis

Symptoms: Itiching

Medication: —

Clinical Procedure: Time-of-flight mass spectrometry (TOF-MS)

Specialty: Infectious Diseases

Updates on Genital Dermatophytosis

Dermatophytes are a group of keratinophilic fungi, which normally cause superficial infection of skin, hair and nails. Based on ecology, they are classified into three groups: anthropophilic, zoophilic and geophilic. Superficial dermatophytic infection of the genital region is called genital dermatophytosis, tinea genitalis or pubo-genital dermatophytosis. In this review, we would like to discuss briefly, the various clinical presentations of genital dermatophytosis, current changes in the taxonomy and nomenclature, introduction of new diagnostic techniques and briefly describe some common dermatophytes and their sources. Also, there are serious concerns associated with the recent development of antifungal resistance among the dermatophytes. We are also facing the scenario of hard-to-treat dermatophytosis.