Maryam Moazeni

Onychomycosis in Tehran: mycological study of 504 patients.

Onychomycosis is a common nail disorder resulting from the invasion of the nail plate by a dermatophyte, yeast or mould species and gives rise to some diverse clinical presentations. The purpose of the present study was to isolate and identify the causative fungi of onychomycosis in the population of Tehran, Iran. Nail samples from 504 patients with prediagnosis of onychomycosis during 2005 were examined both by direct microscopical observation of fungal elements in KOH preparations and in culture for the identification of the causative agent. All samples were inoculated on (i) Sabouraud dextrose agar (SDA, Merck), (ii) SDA with 5% chloramphenicol and cycloheximide in duplicate for dermatophyte and (iii) SDA with 5% chloramphenicol in triplicate for mould isolation. The criteria for the diagnosis of onychomycosis caused by non‐dermatophytic moulds were based on microscopical observation of fungal elements, growth of the same mould in all triplicate culture and no growth of a dermatophyte or yeast in all the cultures. Of 504 cases examined, 216 (42.8%) were mycologically proven cases of onychomycosis (144 fingernails, 72 toenails). Among the positive results, dermatophytes were diagnosed in 46 (21.3%), yeasts in 129 (59.7%) and non‐dermatophytic moulds in 41 (19%). Trichophyton mentagrophytes was the most common causative agent (n = 22), followed by Trichophyton rubrum (n = 13), Candida albicans (n = 42), Candida spp. (n = 56) and Aspergillus spp. (n = 21). Nearly half of the clinically suspected fungal nail infections are onychomycosis and yeast is responsible for most of the infections in Iran.

A case of onychomycosis caused by Aspergillus candidus

Based on epidemiological studies, Aspergillus candidus has been demonstrated as an emerging fungal agent of toenail onychomycosis. Here we report a case of a toenail infection caused by A. candidus in a healthy 60-year-old woman. Based on macroscopic and microscopic characteristics of the culture as well as nucleotide sequencing of 28S region, the causative agent was identified as A. candidus.

Time to overcome fluconazole resistant Candida isolates: Solid lipid nanoparticles as a novel antifungal drug delivery system

Antifungal therapy results in complications in management due to changes in the patterns of epidemiology and drug susceptibility of invasive fungal infections. In this study, we prepared fluconazole-loaded solid lipid nanoparticles (FLZ-SLNs) and investigated the efficacy of the optimal formulation on fluconazole (FLZ)-resistant strains of several Candida species. FLZ-SLN was produced using probe ultrasonication techniques. The morphology of the obtained SLNs was characterized by field emission scanning electron microscopy. The minimum inhibitory concentrations for the new formulations against fluconazole-resistant strains of Candida were investigated using CLSI document M27-A3. The FLZ-SLNs presented a spherical shape with a mean diameter, zeta potential and entrapment efficiency of 84.8nm, -25mV and 89.6%, respectively. The drug release from FLZ-SLNs exhibited burst release behaviour at the initial stage (the first 30min) followed by a sustained release over 24h FLZ-resistant yeast strains behaved as susceptible strains after treatment with FLZ-SLNs (≤8μg/ml). The MIC50 drug concentrations were 2μg/ml, 1μg/ml and 2μg/ml for FLZ-resistant strains of Candida albicans, Candida parapsilosis and Candida glabrata, respectively. In this study, we evaluated novel delivery systems for combating Candida strains that exhibit low susceptibility against the conventional formulation of FLZ as a first-line treatment.

Mucormycosis in Iran: a systematic review

Fungi in the order Mucorales cause acute, invasive and frequently fatal infections in susceptible patients. This study aimed to perform a systematic review of all reported mucormycosis cases during the last 25 years in Iran. After a comprehensive literature search, we identified 98 cases in Iran from 1990–2015. The mean patient age was 39.8 ± 19.2 years. Diabetes was the most common underlying condition (47.9%), and 22.4% of the patients underwent solid organ or bone marrow transplantation. The most common clinical forms of mucormycosis were rhinocerebral (48.9%), pulmonary (9.2%) and cutaneous (9.2%). Eight cases of disseminated disease were identified. Overall mortality in the identified cases was 40.8%, with the highest mortality rate in patients diagnosed with disseminated infection (75%). The mortality rate in rhinocerebral infection patients was significantly lower (45.8%). Rhinocerebral infection was the most common clinical manifestation in diabetes patients (72.9%). Patients were diagnosed using various methods including histopathology (85.7%), microscopy (12.3%) and culture (2.0%). Rhizopus species were the most prevalent (51.7%), followed by Mucor species (17.2%). Sixty‐nine patients were treated with a combination of surgery and antifungal therapy (resulting survival rate, 66.7%). Owing to the high mortality rate of advanced mucormycosis, early diagnosis and treatment may significantly improve survival rates. Therefore, increased monitoring and awareness of this life‐threatening disease is critical.

High prevalence of clinical and environmental triazole-resistant Aspergillus fumigatus in Iran: Is it a challenging issue?

Triazole antifungal agents are the mainstay of aspergillosis treatment. As highlighted in numerous studies, the global increase in the prevalence of triazole resistance could hamper the management of aspergillosis. In the present three-year study, 513 samples (213 clinical and 300 environmental samples) from 10 provinces of Iran were processed and screened in terms of azole resistance (4 and 1 mg l-1 of itraconazole and voriconazole, respectively), using selective plates. Overall, 150 A. fumigatus isolates (71 clinical and 79 environmental isolates) were detected. The isolates were confirmed by partial sequencing of the β-tubulin gene. Afterwards, in vitro antifungal susceptibility tests against triazole agents were performed, based on the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. The CYP51A gene was sequenced in order to detect mutations. The MIC of itraconazole against 10 (6.6 %) strains, including clinical (n=3, 4.2 %) and environmental (n=7, 8.8 %) strains, was higher than the breakpoint and epidemiological cut-off value. Based on the findings, the prevalence of azole-resistant A. fumigatus in Iran has increased remarkablyfrom 3.3 % to 6.6 % in comparison with earlier epidemiological research. Among resistant isolates, TR34/L98H mutations in the CYP51A gene were the most prevalent (n=8, 80 %), whereas other point mutations (F46Y, G54W, Y121F, G138C, M172V, F219C, M220I, D255E, T289F, G432C and G448S mutations) were not detected. Although the number of patients affected by azole-resistant A. fumigatus isolates was limited, strict supervision of clinical azole-resistant A. fumigatus isolates and persistent environmental screening of azole resistance are vital to the development of approaches for the management of azole resistance in human pathogenic fungi.

Extracellular Production of Silver Nanoparticles by Using Three Common Species of Dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis

BACKGROUND To develop a new green approach for biosynthesis of silver nanoparticles, myconanotechnology has been represented as a novel field of study in nanotechnology. In this study, we have reported the extracellular synthesis of highly stable silver nanoparticles using three species of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. METHODS Clinical strains of these species were grown in a liquid medium containing mineral salt and incubated at 25°C for 5-7 days. The cell-free filtrate of each culture was obtained and subjected to synthesize silver nanoparticles in the presence of 1 mM AgNO3. RESULTS The reduction of Ag+ ions in metal nanoparticles was investigated virtually by tracing the solution color which was switched into reddish-light brown after 72 h. For T. mentagrophytes, a UV-visible spectra demonstrating a strong, quite narrow peak located between 422 and 425 nm was obtained. For M. canis, a fairly wide peak centering at 441 nm and for T. rubrum, a weak spectrum to decipher were observed. According to transmission electron microscopy (TEM) results, fairly uniform, spherical, and small in size with almost less than 50 nm particles were forms in case of T. mentagrophytes. For the other two species, TEM images showed existence of small spherical nanosilvers but not as small as nanoparticles synthesized by T. mentagrophytes. CONCLUSION We observed that species belong to a single genus of the fungi have variable ability to synthesize silver nanoparticles extracellulary with different efficiency. Furthermore, the extracellular synthesis may make the process simpler and easier for following processes.

A case of fungus ball type pansinusitis caused by Schizophillum commune.

Schizophillum commune has been increasingly reported from allergic bronchopulmonary mycosis (ABPM) as well as fungus ball, brain abscess and several cases of maxillary or allergic fungal sinusitis. In the present study, we reported a case of fungus ball type pansinusitis from a 32-year-old woman in Iran. According to computed tomography (CT) scan, fungus ball type pan-sinusitis was likely to be the first diagnosis. Mycological examination revealed hyaline hyphae with small projection and also clamp connection structures on PDA medium. To identify the obtained isolate properly, molecular analysis of the internal transcribed spacer region was performed and indicated that the causing agent of the infection is surely Schizophillum commune. The patient completely recovered after surgical endoscopic operation and consequent post-operation MRI revealed clearance of sinuses.

Amino acid substitutions in Erg11p of azole-resistant Candida glabrata: Possible effective substitutions and homology modelling

Understanding the mechanisms responsible for fluconazole resistance in Candida glabrata is not only crucial for the development of new antifungals but is also important in choosing appropriate antifungals for patients at the earliest stages. The aim of this study was to determine the Erg11p amino acid substitutions in fluconazole-resistant C. glabrata isolates. Sixty clinical isolates of C. glabrata were investigated. In vitro antifungal activities of fluconazole, itraconazole and voriconazole were determined using the broth microdilution reference method. The ERG11 gene for resistant (n=4) and susceptible (n=1) isolates were sequenced and multi-aligned using MEGA6 software. A homology model of the C. glabrata ERG11 gene was created by SWISS-MODEL software using the crystal structure of Saccharomyces cerevisiae Erg11p as a template, and the predicted binding sites to fluconazole were investigated. Fluconazole and multi-azole resistance were observed in 6.7% and 3.3% of the isolates, respectively. Several amino acid substitutions were identified, among which some were also identified in susceptible isolates. The amino acid substitution G236V was at the binding site, and substitutions H146Q and D234E were near to the binding site of triazoles according to the SWISS-MODEL. According to the homology modelling results, the amino acid substitution G236V is highly likely to play a key role in azole resistance development.

Improved yeast delivery of fluconazole with a nanostructured lipid carrier system

Despite the growing trends in the number of patients at risk for invasive fungal infections, management with current antifungal agents results in complications due to changes in the epidemiology and drug susceptibility of invasive fungal infections. In the present research fluconazole-loaded nanostructured lipid carriers were prepared using probe ultrasonication techniques and investigated the efficacy of the optimal formulation on a large number of Candida species. The morphology of the obtained nanostructured lipid carriers was characterized by transmission-electron microscopy. The minimum inhibitory concentrations (MIC) for the new formulations against strains of Candida were investigated using the Clinical and Laboratory Standards Institute document M27-A3 and M27-S4 as a guideline. The fluconazole-loaded nanostructured lipid carriers presented a spherical shape with a mean diameter, zeta potential and entrapment efficiency of 126.4±15.2nm, -35.1±3.0mV, and 93.6±3.5%, respectively. The drug release from fluconazole-loaded nanostructured lipid carriers exhibited burst-release behavior at the initial stage followed by sustained release over 24h. Using a new formulation of fluconazole led to a significant decrease in MICs for all Candida groups (P<0.05). Furthermore, C. albicans isolates showed more susceptibility to fluconazole-loaded nanostructured lipid carriers than C. glabrata and C. parapsilosis (P<0.05). The MIC50 drug concentration was obtained as 0.0625, 0.031 and 0.25μg/ml for fluconazole-resistant strains of C. albicans, C. glabrata, and C. parapsilosis, respectively. In conclusion, a novel delivery system which can be used as part of a strategy to improve the antifungal activity of fluconazole against various Candida strains with different susceptibilities to conventional formulations of fluconazole was evaluated.

Microdilution in vitro Antifungal Susceptibility Patterns of Candida Species, From Mild Cutaneous to Bloodstream Infections

Background Candida species, as opportunistic organisms, can cause various clinical manifestations, ranging from mild cutaneous infections to systemic candidiasis in otherwise healthy individuals. Remarkably, the incidence and mortality rates of candidemia have significantly increased worldwide, even after advances in medical interventions and the development of novel antifungal drugs. Objectives Given the possible resistance to antifungal agents, susceptibility testing can be useful in defining the activity spectrum of antifungals and determining the appropriate treatment regime. Materials and Methods The in vitro susceptibilities of molecularly identified Candida strains (n = 150) belonging to seven species recovered from clinical specimens, including vaginal, cutaneous, sputum, bronchoalveolar lavage (BAL), and blood samples, were determined for six antifungal drugs (amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin), based on the clinical and laboratory standards institute’s M27-A3 and M27-S4 documents. Results Candida albicans was the most frequently isolated species (44.66%), followed by non-albicans Candida, including C. glabrata (20%), C. parapsilosis (13.33%), C. krusei (8%), C. tropicalis (7.3%), C. dubliniensis (4%), and C. africana (3.33%). Posaconazole had the lowest geometric mean minimum inhibitory concentration (MIC) (0.0122 µg/ml), followed by amphotericin B (0.0217 µg/mL), voriconazole (0.1022 µg/mL), itraconazole (0.1612 µg/mL), caspofungin (0.2525 µg/mL), and fluconazole (0.4874 µg/mL) against all isolated Candida species. Candida africana and C. parapsilosis were significantly more susceptible to fluconazole, compared to C. albicans and other Candida species (P < 0.001). However, their clinical effectiveness in the treatment of Candida infections remains to be determined. Conclusions These findings highlight the importance of precise and correct species identification of clinical yeast isolates via molecular approaches, and of monitoring the antifungal susceptibility of Candida species recovered from clinical sources. Laboratories should consider routine MIC testing of C. glabrata isolates collected from sterile sites. Surveillance studies of Candida species and new analyses of antifungal treatment outcomes will allow more informed determinations of the value of these drugs in the antifungal armamentarium.