Antifungal susceptibility testing for dermatophytes isolated from clinical samples by microbroth dilution method

Background: The cases of dermatophytoses have increased over the past few decades. Dermatophytoses affect the outer layers of skin, nails and hairs without tissue invasion. These infections are mostly not dangerous but, are important as public health problem particularly in the immunocompromised. The increased use of antifungal drugs for prolonged periods may lead to acquired antifungal resistance among previously susceptible strains. With this background present study was conducted to know the susceptibility pattern of dermatophytes.Methods: A total 35 isolates of dermatophytes isolated from clinically suspected cases of dermatophytoses were examined. Broth microdilution method M38-A2 approved protocol of CLSI (2008) for filamentous fungi was followed for determining the susceptibility of dermatophyte species to antifungal agents- itraconaole, fluconazole and ketoconazole.Results: Itraconazole minimum inhibitory concentrations (MIC) varied from 0.0156 to 1 µg/ml for all dermatophytes. T. rubrum species showed higher MIC range for Ketoconazole than T. mentagrophytes and T. tonsurans. Fluconazole had poor susceptibility for all dermatophytes by having higher MIC values.Conclusions: The MIC values observed in present study will help clinician to select an appropriate antifungal agent with minimal side effects. The data from present study can be useful as reference for future studies covering large no. of isolates and more drugs.

Prevalence of Dermatophytosis in patients in a tertiary care centre in and around Cuddalore district

Background: The common cause of skin infections are dermatophytes and opportunistic fungi. Aim of this study was to isolate and identify the fungal agents from clinical samples from patients with different mycoses. Superficial mycoses are among the most frequent forms of human infections, affecting more than 20–25% of the world’ population. They are predominantly caused by a group of closely related keratinophilic mycelia fungi (dermato-phytes) in the genera of Trichophyton, Microsporum, and Epidermophyton. These groups of fungi invade the stratum corneum of the skin or other keratinized tissues derived from the epidermis such as hair and nails. Aim and objectives: The present work aims at evaluation of rate of incidences of dermatophytic infections (group wise), and etiological agents with associated symptoms. In addition, we also determine to test the sensitivity of present diagnostic procedures. Materials and methods: Samples were collected from 100 patients. A portion of each sample was examined microscopically and the remaining portion of each sample was cultured onto plates of Sabouraud’s dextrose agar containing chloramphenicol with and without cycloheximide. Dermatophyte isolates were identified by studying macroscopic and microscopic characteristics of their colonies .Preliminary identification was done by conventional methods and confirmed by Polymerase Chain Reaction – Restriction Fragment length Polymorphism (PCR -RFLP) technique. Results: All over 62/100 specimens were KOH positive and 48/62 (82.7%) samples were culture positive. Of these, highest isolation rate was obtained in opportunistic mycoses such as candidiasis (29/29, 100%). Dermatophytes were isolated in 41/62 (66.3%) specimens and Trichophyton rubrum was the commonest isolate in skin samples (44/62) among the patients suffering from dermatophytosis. Phaeoannellomyces Wernicke was isolated in a patient suffering from tinea nigra. P. Gunasekaran. Prevalence of Dermatophytosis in patients in a tertiary care centre in and around Cuddalore district. IAIM, 2017; 4(8): 91-95. Page 92 The study signifies the importance of mycological examination in the diagnosis of various mycoses for their effective management. Conclusion: Dermatophytoses are distributed worldwide with increased incidence especially in a tropical country like India. Several factors such as age, sex, illiteracy, poor hygiene and social economy influence the dermatophyte infection. In the present study we have attempted to understand the epidemological status of the dermatophytes in a tertiary care centre in Cuddalore, Tamil Nadu, India. Tinea corporis was the predominant clinical site from which dermatophytes were isolated. T. Rubrum and T. Mentagrophytes have been the major etiological agents and that has been evinced by our study.

Dermatophytosis diagnosed at the Evandro Chagas Institute, Pará, Brazil

Dermatophytosis is caused by a dermatophyte fungus that affects the stratum corneum and keratinized tissue. Dermatophyte fungus has been reported worldwide as the causative agent of dermatophytosis, but the etio-epidemiological aspects of these mycoses in the state of Pará remain unknown. The purpose of this study was to describe the etio-epidemiological profile of dermatophytosis diagnosed in patients at the Evandro Chagas Institute from May 2005 to June 2006. A total of 494 patients were admitted, and their samples were collected, submitted for direct microscopic examination using 20% KOH and cultured in Sabouraud and Mycosel medium. The identification was based in macro and microscopic characteristics. Direct examinations were positive in 13% (66/494) of the patients, and agent isolation by cultivation of the biological sample was successful in 4% (20/494), with a high prevalence of T. mentagrophytes (40%; 8/20). Dermatophytosis was more frequent in women (58%; 38/66). Fifty-two percent (21/38) of the cases were children with an average age of 8 years. The most frequent clinical presentation was Tinea corporis (55%, 36/66). For the cases in which the dermatophyte agent was not isolated, we discuss the factors that may be interfering with isolation. Tinea corporis occurred more frequently observed when T. mentagrophytes and T. rubrum were the major etiologic agents.

Four Cases of Majocchi's granuloma / 대한의진균학회지

Dermatophytes usually do not invade beyond the epidermis. However mechanical breakage of the skin resulting from scratching or trauma and immunocompromised state, such as diabetes mellitus, lymphoma, and long-term steroid use may allow penetration of the fungi into reticular dermis. Cutaneous granulomas produced by infection with superficial fungi are infrequently recognized. We report four cases of dermatophytic granuloma on the lower extremities. Histopathologic examinations of the skin lesions of four patients showed chronic granulomatous inflammation with fungal elements. Cultures of Sabouraud's media with excised tissue revealed Trichophyton(T.) rubrum in two patients and T. mentagrophytes in one patient. The patients were treated with oral administration of terbinafine or itraconazole for 2-4 weeks.

Relationship between Candida albicans producing proteinase (CAPP) and its environmental pH--comparison with a case of trichophyton mentagrophytes

Candida albicans produced a karatinolytic proteinase (KPase) or C. albicans producing proteinase (CAPP), a proposed new term for this enzyme, and Trichophyton mentagrophytes also produced KPase when cultivated in liquid medium containing human stratum corneum (HSC) as the nitrogen source, but were unable to do so when cultivated in sabouraud dextrose broth. Purified KPase from the culture supernatants of C. albicans had a molecular weight of 42,000 and an optimum pH at 4.0. The KPase was found to belong to the carboxyl proteinases group and its activity was strongly inhibited by pepstatin. Both fungi were able to grow by secreting KPase which digested HSC for nutrients. KPase from both fungi had high activity in each optimum pH, such as weakly acidic pH on C. albicans and neutral pH on T. mentagrophytes to adapt their surrounding environment by changing the environmental pH into their own optimum pH.