P107 Spectrum of Dermatophyte infections and drug susceptibility pattern of Dermatophytes in patients visiting to tertiary care hospital in Chhattisgarh state of India
Authors: Keche Archana , Das Padma , Sharma Pratibha , Ganguly Satyaki , Chhabra Namrata , Shivaprakash MR 
Published: September 2022

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM

 

Objectives

1. To isolate and identify various species of Dermatophytes from clinical specimens 2. To perform and analyze the antifungal susceptibility testing of isolated Dermatophytes for commonly used antifungal agents; terbinafine and itraconazole.

Methods

A prospective study was conducted from December 2019 to October 2021. Clinical specimens (skin, hair, and nail) from suspected cases of dermatophytosis were received and processed in the department of microbiology. All the samples were subjected to microscopic examination and culture by standard techniques. Their clinico-demographic profile was obtained. Specimen were processed for KOH and fungal culture. Dermatophytes were identified by studying macroscopic and microscopic characteristics of the isolates. The conidium-forming dermatophyte isolates were processed for antifungal susceptibility testing for terbinafine and itraconazole by Microbroth dilution testing following the CLSI M-38A2 guidelines.

Results

Total 248 patients with male predominance (68%) were noted in the above-mentioned study period. Predominance of study population belonged to rural area. Maximum numbers of cases were from the age group 21-30 years. Majority of patients belong to poor socioeconomic status. Out of 248 samples, 178 (72%) had a positive KOH mount amongst which 72% had positive culture results. Amongst 2 4881% were skin scraping, 17% were nail, and 1.6% hair samples were processed. Out of culture-positive samples 52% were Dermatophytes. The most clinical form of dermatophytosis was combination of both Tinea cruris and T. carporis (31%) followed by T. cruris (22%), and T. corporis (17%) for which skin scraping was processed. The most common isolate was Trichophyton tonsurans (73%) followed by T. mentagrophytes (10%), and T. verrucosum. Onychomycosis was diagnosed in 17% patients of which 59% were positive by KOH 49% were culture positive.11.5% isolates from nails were dermatophytes.

Antifungal susceptibility testing was done by Microbroth dilution method and analyzed the range. The MIC range of major isolates, i.e., T. tonsurans showed MIC ranges against terbinafine &lt;0.03-4 μg/ml and itraconazole 0.03-2 μg/ml. Trichophyton mentagrophyte for terbinafine &lt;0.12-4 μg/ml and for itraconazole 0.12-2 μg/ml. Four isolates of T. tonsurans had higher MIC values for terbinafine and two isolates had higher MIC for itraconazole. One isolate of T. mentagrophytes had higher MIC values of itraconazole, and one another isolate had higher MIC for terbinafine.

Conclusion

This study highlights the change in pattern of causative agents of dermatophytosis. The present study showed the predominance of T. tonsurans. More extensive studies are needed to evaluate the cut-off range of antifungal susceptibility testing of dermatophytes with clinical follow-up to see the response of respective antifungals and to guide the therapy.