Dermatophytic Infections and Their Antifungal Susceptibility Pattern in Rajshahi

Abstract

Background: Dermatophytosis is a common skin disease affecting millions of people worldwide. These infections occur in both healthy and immunocompromised patients. Conventional methods for detecting fungi in clinical specimens are either microscopy or culture. Now a days, resistant to antifungal drugs by the dermatophytes can result in treatment failure. Antifungal susceptibility testing of dermatophytes may help in the management of patients, cases presenting with therapy failure and may help to choose more efficacious antifungal agents. Objectives: To detect different dermatophytes and their antifungal susceptibility pattern, and antifungal diagnostic accuracy of microscopy test in comparison of culture. Methods: This cross-sectional type of descriptive study was conducted among the attending patients at the Department of Microbiolo- gy, Rajshahi Medical College and outpatient department of Dermatology and Venereology, Rajshahi Medical College Hospital (RMCH) Different clinical samples (e.g., skin scrapings, nail clipping and hair plucking) were collected under aseptic precautions. A total 171 specimens were collected in this study. The isolation and identification of dermatophytes was performed through microscopic examination using 10% KOH mount, mycological culture and species identification by lactophenol cotton blue mount from positive culture. All dermatophytes’ isolates were subjected to antifungal susceptibility testing using the agar-based disk diffusion method in Mueller Hinton agar media. The sensitivity, specifici- ty and accuracy of microscopy test were calculated in comparison of fungal culture. Results: Out of 171 samples, 92 (53.8%%) were positive by direct microscopy with KOH mount microscopy, 106(62%) were posi- tive by culture. Trichophyton rubrum was the predominant dermatophyte species with 76(71.7%) followed by T.mentagrophyte were 15(14.2%). Voriconazole, Clotrimazole and Itraconazole were more effective drugs. Griseofulvin and Fluconazole were the least effective drug. The sensitiv- ity, specificity and accuracy of the KOH mount microscopy were 74.53%, 80.00% and 76.61% respectively. Conclusion: Trichophyton rubrum was the commonest dermatophyte species in this study population. Voriconazole, Clotrimazole and Itraconazole were more effective drugs. Antifungal diagnostic accuracy of microscopy test was optimal level specially positive predictive value and specificity. KOH mount microsco- py test may be used for the screening and diagnostic purpose because it’s an easy, fast and inexpensive method. When the microscopy test result will not correlate with the clinical findings then physician should be advised for culture.