Identification and Antifungal Susceptibility Testing of Fungal Infections in Clinical Samples of Suspected Superficial Fungal Infections

Abstract

Introduction-Fungi are worldwide in distribution but only few of them are considered as pathogenic. As the fungal infections are not notifiable infections like viral, parasitic, bacterial diseases hence these are not given much attention and usually the diagnosis is established very late. In response to the increased incidence of fungal infections, the pharmaceutical industry has developed a number of newer less toxic anti-fungal drugs for clinical use. The increased use of antifungal drugs, often for prolonged periods, has led to acquired antifungal resistance among previously susceptible strains or species and to the increased incidents of infections with less common species. Objective-To study the fungal isolates in relation to site of infection/specimen and to establish in vitro anti-fungal susceptibility testing. Materials and Methods-The study was conducted during January 2007 to December 2008 Pad. Dr. D.Y. Patil Medical College and Hospital Pimpri, Pune-18. Total 120 clinically suspected cases of superficial fungal infections were collected for study from various wards and OPDs of hospital. Results and Observation-Superficial fungal infection occurs mainly in younger age group and adults. In the present study males were more affected than females. Most common clinically diagnosed cases in superficial fungal infection of skin were of Tinea corporis, T. pedis and T. cruris. Among dermatophytes, T. rubrum was the commonest etiological agent followed by T. mentagrophytes. Amongst the non-dermatophyte moulds, Aspergillus spp. was the most prevalent species. SAAS method showed potential as a screen for antifungal susceptibility testing. Anti-fungal susceptibility testing of dermatophytes (Trichophyton rubrum was done by semi-solid agar dilution method using ant-fungal drug terbinafine. All isolates were sensitive. MIC of all isolates were 0.25µg/ml. Conclusion-To reduce the time required for anti-fungal susceptibility testing of filamentous fungi, semi-solid agar susceptibility method uses inoculums suspensions that can be readily prepared from the original pure plate. The test can even set up as soon as the mould is isolated. No special expertise or expensive equipments is needed, because the procedure is simple and similar for all fungi.