Antifungal Resistant Pattern of Tricophyton Rubrum and Tricophyton Mentagrophytes at a Tertiary Care Hospital in Bangladesh

Background: Dermatophytoses are caused by keratinophilic fungi called dermatophytes, which can invade keratinized tissue. Dermatophytoses is a serious health concern in regions with high humidity, dense population density, and poor sanitary conditions. Many antifungal drugs are available to treat this infection but in routine clinical practice, these antifungal drugs are not always effective. For this reason, antifungal susceptibility test is an epidemiological concern to reduce the dermatophytic infection. Objective: This study was aimed to evaluate the susceptibility patterns of Tricophyton Rubrum and Tricophyton Mentagrophytes to antifungal drugs. Methods: To determine the pattern of antifungal susceptibility in dermatophytes, this study comprised 246 patients with a clinical diagnosis of dermophytoses across all age groups. The skin, hair, and nails were sampled in an aseptic manner. These samples were mounted in potassium hydroxide (KOH) and cultured on sabouraud dextrose agar (SDA). Direct microscopy and culture method were used in diagnosis of dermatophytosis. Polymerase chain reaction (PCR) and biochemical tests (urease test and hair perforation test) were used to identify dermatophyte species. An established colony was cultivated on potato dextrose agar (PDA) for sensitivity testing. Following notable sporulation, the spores were collected in normal saline and a standardized inoculum adjusted with 0.5 Mcfarland solution was applied to SDA plates, which were then incubated at room temperature (26-28˚C). After three to seven days, the zone of inhibition was evaluated and the drug's sensitivity, intermediate level, or resistance was determined accordingly. Results: It was observed that, thirty-one (93.55%) Trichophyton rubrum and 45 (91.11%) Trichophyton mentagrophytes were resistant to fluconazole. Twenty (64.52%) Trichophyton rubrum and 30 (66.67%) Trichophyton mentagrophyte were resistant to terbinafine. Resistant to itraconazole and voriconazole were ...