In vivo and in vitro Pathogenesis and Virulence Factors of Candida albicans Strains Isolated from Cutaneous Candidiasis.

Background: The Candida albicans is one of the most important global opportunistic pathogens, and the incidence of candidiasis has increased over the past few decades. Despite the established role of skin in defense against fungal invasion, little has been documented about the pathogenesis of Candida species when changing from normal flora to pathogens of vaginal and gastrointestinal epithelia. This study was carried out to determine the in vivo and in vitro pathogenesis of clinical C. albicans strains isolated from skin lesions. Methods: In this study, association of in vivo and in vitro pathogenesis of C. albicans isolates with different evolutionary origins was investigated. Oral and systemic experimental candidiasis was established in BALB/C mice. The expression levels of secreted aspartyl proteinases (SAP1-3 genes), morphological transformation, and biofilm-forming ability of C. albicans were evaluated. Results: All the strains showed in vitro and in vivo pathogenicity by various extents. The SAP1, SAP2, and SAP3 genes were expressed in 50%, 100%, and 75% of the strains, respectively. The biofilm formation ability was negative in 12% of the strains, while it was considerable in 38% of the strains. Fifty percent of the strains had no phospholipase activity, and no one demonstrated high level of this pathogenesis factor. Relatively all the strains had very low potency to form pseudohyphae. Conclusion: Our findings demonstrated that Candida albicans strains isolated from cutaneous candidiasis were able to cause oral and systemic infections in mice, so they could be considered as the potential agents of life-threatening nosocomial candidiasis in susceptible populations.

Cutaneous candidiasis in Tehran-Iran: from epidemiology to multilocus sequence types, virulence factors and antifungal susceptibility of etiologic Candida species.

BACKGROUND AND OBJECTIVES: Cutaneous candidiasis is a multipicture fungal infection caused by members of the genus Candida which is considered as a public health problem all over the world with urgency of effective treatment and control. This study was performed to analyze the clinical epidemiology and molecular aspects of cutaneous candidiasis in Tehran-Iran in relation to antifungal susceptibility and virulence factors of etiologic Candida species. MATERIALS AND METHODS: Candida species were isolated from skin (27.3%) and nail scrapings (72.7%) of suspected patients and identified by ITS sequencing. Phylogeny of the isolates was evaluated using multilocus sequence typing (MLST) and antifungal susceptibility and virulence factors of the isolates were determined in relation to clinical presentation. RESULTS: Candida albicans was the most prevalent species (39.8%), followed by C. parapsilosis (32.9%), C. orthopsilosis (10.4%), C. tropicalis (7.9%), C. glabrata and C. guilliermondii, each (4.5%). Molecular typing of 35 C. albicans isolates by MLST revealed 28 novel sequence types with 11 singletons with 80.0% new diploid sequence types (DSTs). Majority of the isolates were susceptible to amphotericin B (91.5%), followed by posaconazole (90.3%), fluconazole (84.3%), itraconazole (74.1%), caspofungin (53.6%), and voriconazole (26.8%). Biofilm formation, yeast-to-hyphae transformation and phospholipase activity were reported species-dependent. CONCLUSION: Our results demonstrated clinical epidemiology of various Candida species from cutaneous candidiasis distributed in new molecular types with increasing importance of drug resistant of non-albicans Candida species. Our results showed that drug susceptibility and genetic variability of Candida species may be attributed to their clinical features and source of isolation.

Clinical and epidemiological features of the genus Malassezia in Iran.

BACKGROUND AND OBJECTIVES: The genus Malassezia contains an expanding list of lipophilic yeasts involve in the etiology of various superficial fungal infections. Pityriasis versicolor (PV) is the most prevalent Malassezia-related infection distributed worldwide. In the present study, clinical and epidemiological features of the genus Malassezia are discussed with special focus on PV in Iran. MATERIALS AND METHODS: During June 2012 to April 2013, among 713 confirmed cases of fungal infections, 68 (9.5%) were diagnosed as PV by positive direct microscopy results in 20% potassium hydroxide (KOH) preparation of skin scrapings. All the specimens were cultured on modified Dixon agar and incubated at 32°C for 10 days. Identification of the isolated yeasts was carried out based on macro- and microscopic morphology, catalase test, utilization of Tweens, polyethoxylated castor oil (EL slant), and hydrolysis of esculin and utilization of Tween-60 (TE slant). RESULTS: Out of 68 skin scrapings, 55 (80.9%) yielded yeast colonies on mDixon's agar which were finally identified as M. globosa (36.36%), M. pachydermatis (29.08%), M. furfur (23.65%), M. slooffiae (7.28%) and M. obtusa (3.64%). CONCLUSION: Results of the present study further indicate clinico-epidemiological importance of the genus Malassezia with growing importance of M. pachydermatis as a major species involve in the etiology of pityriasis versicolor. These findings are of major concern in management of Malassezia-related diseases.

Evaluation of the association of superficial dermatophytosis and athletic activities with special reference to its prevention and control.

OBJECTIVE: This study was conducted to evaluate the association of superficial mycosis and athletic activities with special references to its prevention and control in Tehran. Participating in various kinds of sports can lead to direct and indirect exposures to and transmission of micro-organisms between athletes and also passive observers. METHODS: A retrospective study of superficial fungal infections in athletes was carried out during the period of March 2002 to December 2006 on 656 mycological proven cases of dermatophytosis found in athletes in Tehran. Mycologic examination consisted of culturing of pathologic material followed by direct microscopic observation. Mycologic cultures were carried out on Sabouraud Chloramphenicol Agar, Sabouraud Chloramphenicol and Cyclohexamide Agar, and Dermatophyte Agar incubated at 25 °C for at least 28 d. Diagnosis was based on macroscopic and microscopic characteristics of the colonies. RESULTS: A total of 1075 athletes, from 201 institutions, suspected of cutaneous fungal infections were examined and 656 (61%) were found to be positive for fungal infections. The fungal isolates comprised Trichophyton tonsurans (56%), Epidermophyton floccosum (11.8%), Trichophyton mentagrophytes (8.9%), Trichophyton rubrum (8.3%), Trichophyton verrucosum (3.9%), Trichophyton violaceum (3.3%), Microsporum canis (2.5%), and Malassezia spp. (5.3%). The distribution of lesions on the body in decreasing order was as follows: trunk, groin, hair and scalp, sole, toe webs, finger nails, and toe nails. Fungal infections were more commonly seen in wrestlers and individuals that participate in aerobics. CONCLUSION: The results suggest that athletic activity seems to be a predisposing factor, especially for fungal infections. Guidelines are provided regarding measures to prevent transmission of infectious diseases in athletic settings, including hygiene, infection control practices, and education of officials, coaches, trainers, and sports participants.

Fungistatic effects of optical brightener 220 against Trichophyton tonsurans, Aspergillus fumigatus and Candida albicans.

BACKGROUND: Dermatophytes are one of the main causes of dermal infections. Moreover, there are some opportunistic fungi such as Aspergillus fumigatus (mycelial form) and Candida albicans (yeasty form) that in immunosuppressed patients can cause cutaneous disease. OBJECTIVES: The possible effect of optical brightener 220 (OB-220) on the growth of fungi has been evaluated in this study. METHODS: Isolates were grown on agar plates containing OB-220 in concentration between 0.06 and 11.68 mg ml(-1). MICs of OB-220, ketoconazole and fluconazole were obtained by the agar dilution method. Hyphae and yeasts grown with OB-220 were compared with controls by fluorescence and transmission electron microscopy. The cell cytotoxicity of OB-220 was also assessed. RESULTS: The MIC(90) of OB-220 was obtained: 1.17-1.46 mg ml(-1) for A. fumigatus, 0.58-1.17 mg ml(-1) for C. albicans and 0.29 mg ml(-1) for Trichophyton tonsurans. Electron microscopy revealed a thickening and blurred contours of the cell wall by OB-220. OB-220 in concentrations up to 11.68 mg ml(-1) posed no mammalian cell toxicity. CONCLUSION: OB-220 suppresses the growth of fungi by interfering with the formation of normal chitin.

In vitro antifungal activities of Allium cepa, Allium sativum and ketoconazole against some pathogenic yeasts and dermatophytes.

By using an agar dilution assay, the antifungal activity of aqueous extracts prepared from Allium cepa (onion; AOE) and Allium sativum (garlic; AGE) were evaluated against Malassezia furfur (25 strains), Candida albicans (18 strains), other Candida sp. (12 strains) as well as 35 strains of various dermatophyte species and compared with the activity of a known antifungal drug, ketoconazole (KTZ). All the AOE, AGE and KTZ were found to be able to inhibit growth of all fungi tested in a dose-dependent manner with maximum of 100% at defined concentrations. The results indicate that onion and garlic might be promising in treatment of fungal-associated diseases from important pathogenic genera Candida, Malassezia and the dermatophytes.