Determination of Ergosterol as a Potential Biomarker in Pathogenic Medically Important Fungal Isolates / Jurnal Sains Kesihatan Malaysia

Ergosterol, a component of fungal cell membrane, has been frequently detected as an indicator of fungal presence and massin environmental samples like soil. However, its detection in major pathogenic fungal species has not been investigated.In this study, the ergosterol contents of ten pathogenic fungal species were determined. Liquid chromatography was usedfor the detection and quantification of ergosterol extracted from fungal broth cultures. Results showed that ergosteroleluted as a single, well resolved peak in the chromatogram profiles of all tested fungi. Based upon relative amounts ofergosterol produced per fungal mycelial dry weight, three groups of fungal pathogens were identified, namely low ergosterol(Aspergillus niger, Candida albicans and Cryptococcus neoformans at 4.62, 6.29 and 7.08 μg/mg, respectively), mediumergosterol (Fusarium solani, Aspergillus fumigatus, Mucor sp., Penicillium sp., Cryptococcus gattii and Rhizopus sp.at 9.40, 10.79, 10.82, 11.38, 12.60 and 13.40 μg/mg, respectively), and high ergosterol (Candida tropicalis at 22.84 μg/mg), producers. Ergosterol was not detectable in bacterial samples, which were included as controls. This first report onergosterol detection in major pathogenic fungal species indicates that ergosterol may be used as a biomarker to diagnoseinvasive fungal infections in clinical sampl

In Vitro Antifungal Activities against Moulds Isolated from Dermatological Specimens

Background: This study aimed to determine the minimum inhibitory concentrations (MICs) of various antifungal agents against moulds isolated from dermatological specimens. Methods: We identified 29 moulds from dermatological specimens between October 2012 and March 2013 by conventional methods. We performed antifungal susceptibility testing on six antifungal agents, amphotericin B, clotrimazole, itraconazole, ketoconazole, miconazole and terbinafine, according to the Clinical and Laboratory Standards Institute guidelines contained in the M38-A2 document. Results: Most antifungal agents were active against the dermatophytes, except for terbinafine against Trichophyton rubrum (geometric mean MIC, MICGM 3.17 µg/mL). The dematiaceous moulds were relatively susceptible to amphotericin B and azoles (MICGM 0.17-0.34 µg/mL), but not to terbinafine (MICGM 3.62 µg/mL). Septate hyaline moulds showed variable results between the relatively more susceptible Aspergillus spp. (MICGM 0.25-4 µg/mL) and the more resistant Fusarium spp. (MICGM 5.66-32 µg/mL). The zygomycetes were susceptible to amphotericin B (MICGM 0.5 µg/mL) and clotrimazole (MICGM 0.08 µg/mL), but not to other azoles (MICGM 2.52-4 µg/mL). Conclusion: Amphotericin B and clotrimazole were the most effective antifungal agents against all moulds excepting Fusarium spp., while terbinafine was useful against dermatophytes (except T. rubrum) and Aspergillus spp. However, a larger study is required to draw more solid conclusions.

Sporotrichosis atypical presentation as a soft tissue tumour

Sporotrichosis is a mycosis caused by a saprophytic dimorphic fungus named Sporothrix schenckii. Infections occur following traumatic inoculation of fungus from plants and infected cat bites and scratches. We report a case of a farmer who presented with a solitary subcutaneous nodule initially diagnosed as a soft tissue tumour. A history of agricultural activity and feline contact should draw the clinician's attention to sporotrichosis, as the diagnosis can be easily missed in atypical cases. The diagnosis, microbiology and management of the case are discussed.