In vitro antifungal susceptibility of Trichophyton violaceum isolated from tinea capitis patients

Dermoscopic findings in Tinea Capitis among under 18 children in dermatology polyclinic patients: a hospital-based cross-sectional study

Background

Tinea capitis is a fungal infection that affects the scalp. It is caused by a group of fungi known as dermatophytes, which thrive in warm and moist environments. In Somalia, there is a data shortage regarding dermatological conditions, especially in Mogadishu, the most populous city in the country. Tinea capitis has gone unreported despite its high prevalence in Somali dermatology clinics and the Somali diaspora in Western countries. The absence of up-to-date information hampers the capability to diagnose, treat, and prevent Tinea capitis. Therefore, the study aims to evaluate dermoscopic signs about isolated organisms and potassium hydroxide (KOH) examination.

Method

A hospital-based cross-sectional study was implemented between January and April 2023 in Mogadishu, Somalia. All eligible Tinea capitis-infected children were included in the study. Microscopically, analysis was conducted by adding 10% of KOH in fungal elements. Data were analyzed using descriptive statistics and the χ2 test at P value less than 0.05.

Results

A total of 76 tinea capitis-infected children participated in the study; 56% were age group between 5-9 years old, 68.4% were male, and 92.1% showed KOH positivity. Trichophyton violaceum (65.8%) and Trichophyton sudanense (14.5%) were the most common fungal organisms detected in the culture. comma hairs (93.10%), scales (40.80%), and corkscrews (32.90%) were the most common dermoscopic signs of tinea capitis. The demographical characteristics and dermoscopic signs of tinea capitis significantly associated with the positivity of KOH examination were age, sex, comma hairs, corkscrew hairs, broken hair, Scales, and Zigzag hair.

Conclusion

Children in Mogadishu, Somalia, bear a significant burden of Tinea Capitis infections. Trichophyton violaceum and Trichophyton sudanense were the predominant causative agents identified in the cultures. The most common dermoscopic signs of tinea capitis observed in this study were comma hairs, scales, and corkscrew patterns. Hence, early diagnosis of Tinea Capitis infections and timely, effective treatments with contact tracing are highly needed.

In vitro antifungal susceptibility patterns of Trichophyton benhamiae complex isolates from diverse origin

BACKGROUND

Species from the Trichophyton benhamiae complex are mostly zoophilic dermatophytes which cause inflammatory dermatophytosis in animals and humans worldwide.

OBJECTIVES

This study was purposed to (a) to identify 169 reference and clinical dermatophyte strains from the T benhamiae complex species by molecular method and adhering to the newest taxonomy in the complex (b) to evaluate the in vitro antifungal susceptibility profile of these strains against eight common and new antifungal agents that may be used for the treatment of dermatophytosis.

METHODS

All isolates, mainly originated from Europe but also from Iran, Japan and USA, were subjected to ITS-rDNA sequencing. The in vitro antifungal susceptibility profiles of eight common and new antifungal drugs against the isolates were determined by CLSI M38-A2 protocol and according to microdilution method.

RESULTS

Based on the ITS-rDNA sequencing, T benhamiae was the dominant species (n = 102), followed by T europaeum (n = 29), T erinacei (n = 23), T japonicum (n = 10), Trichophyton sp (n = 4) and T eriotrephon (n = 1). MIC ranges across all isolates were as follows: luliconazole: 0.0002-0.002 µg/ml, terbinafine: 0.008-0.125 µg/ml, efinaconazole: 0.008-0.125 µg/ml, ciclopirox olamine: 0.03-0.5 µg/ml, itraconazole: 0.06-2 µg/ml, griseofulvin: 0.25-4 µg/ml, amorolfine hydrochloride: 0.125-4 µg/ml and tavaborole: 1-16 µg/ml.

CONCLUSION

Luliconazole, efinaconazole and terbinafine were the most potent antifungals against T benhamiae complex isolates, regardless of the geographic locations where strains were isolated. These data might help dermatologists to develop effective therapies for successful treatment of infections due to T benhamiae complex species.

Evaluation of susceptibility and response in the surface of agents of surface mycoses (Trichophyton mentagrophytes; T. tonsurans) to antifungal drugs of interest in a medical clinic

Introduction: The resistance of fungal species to drugs usually used in clinics is of great interest in the medical field. Objective: To evaluate susceptibility and in vitro response of species of Trichophyton spp. to antifungal drugs of interest in clinical medicine. Methods: 12 samples of clinical isolates from humans were used, nine of T. mentagrophytes and three of T. tonsurans. Susceptibility tests were performed according to the agar diffusion (AD) and broth microdilution (BM) methods. Results: In the AD method, the species T. tonsurans presented a percentage of sensitivity of 33% in relation to amphotericin B and 66% to itraconazole, with 100% resistance to ketoconazole and fluconazole. T. mentagrophytes also showed 100% resistance to ketoconazole in this technique, with 11% sensitivity to ketoconazole, 22% to itraconazole and 22% of samples classified as sensitive dose dependent. In the MC method, the species T. tonsurans presented a sensitivity percentage of 66%, 55% and 33% in relation to ketoconazole, fluconazole and itraconazole, respectively. The T. mentagrophytes species presented sensitivity percentages of 11%, 11%, 33% and 55% for amphotericin B, itraconazole, ketoconazole and fluconazole, respectively. Conclusion: There was resistance in vitro of the species of T. mentagrophytes and T. tonsurans against the antifungal fluconazole and relative resistance against ketoconazole in the AD method. In BM, however, important percentages of sensitivity were observed for the two species analyzed in relation to the antifungals fluconazole and ketoconazole when compared to itraconazole and amphotericin B.

In Vitro Antifungal Susceptibility Profiles of 12 Antifungal Drugs against 55 Trichophyton schoenleinii Isolates from Tinea Capitis Favosa Patients in Iran, Turkey, and China

Trichophyton schoenleinii is an anthropophilic dermatophyte mainly causing tinea favosa of the scalp in certain regions of the world, especially Africa and Asia. We investigated the in vitro susceptibilities of 55 T. schoenleinii isolates collected over the last 30 years from Iran, Turkey, and China to 12 antifungals using the CLSI broth microdilution method. Our results revealed that terbinafine and ketoconazole were the most potent antifungal agents among those tested, independently of the geographic regions where strains were isolated.

Comparison of the in vitro activities of newer triazoles and established antifungal agents against Trichophyton rubrum

One hundred eleven clinical Trichophyton rubrum isolates were tested against 7 antifungal agents. The geometric mean MICs of all isolates were, in increasing order: terbinafine, 0.03 mg/liter; voriconazole, 0.05 mg/liter; posaconazole, 0.11 mg/liter; isavuconazole, 0.13 mg/liter; itraconazole, 0.26 mg/liter; griseofulvin, 1.65 mg/liter; and fluconazole, 2.12 mg/liter.