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

## TL;DR

This study tested antifungal susceptibility in Trichophyton mentagrophytes isolates from dermatophytosis patients in India, finding itraconazole more effective than fluconazole.

## Contribution

The study introduces the E-test method as a practical alternative to traditional methods for antifungal susceptibility testing in dermatophytes.

## Key findings

- Itraconazole showed higher effectiveness compared to fluconazole against Trichophyton mentagrophytes isolates.
- Trichophyton mentagrophytes was the most common cause of dermatophytosis in the studied population.
- The E-test method proved to be a feasible and practical tool for antifungal susceptibility testing in routine laboratories.

## Abstract

Introduction

Dermatophytosis is a common infection of the skin, hair, and nails caused by dermatophytes, a group of filamentous fungi capable of digesting and obtaining nutrients from keratin. Dermatophytes comprise three important genera: Epidermophyton, Microsporum,and Trichophyton. This study aimed to analyze the antifungal susceptibility patterns of Trichophyton mentagrophytes isolates using the epsilometer test (E-test) method.

Material and methods

This prospective observational study was conducted on clinically suspected cases of dermatophytosis. All samples, including skin scrapings, hair, and nails, were subjected to potassium hydroxide (KOH) examination followed by fungal culture. The Trichophyton mentagrophytes isolates were then subjected to antifungal susceptibility testing using the E-test method for the two most prescribed antifungals: itraconazole and fluconazole.

Results

In this study, one-third of the patients who tested positive for dermatophytosis belonged to the same family, with spouses being the most commonly affected. Tinea corporis was the most common clinical presentation, with Trichophyton mentagrophytes identified as the most common etiological agent. Itraconazole was more effective than fluconazole.

Conclusion

The current study demonstrated that antifungal susceptibility testing of dermatophytes using the E-test is easier and can be applied in routine laboratories as a screening method, serving as an alternative to broth microdilution.