The genus Aspergillus, which consists of a few hundred opportunistic mold species found in various climatic conditions, causes diseases including localized infections, fatal diseases, allergic responses, and inhaled conidia in humans. Herein, we present an overview of the most common diseases and allergic infections caused by Aspergillus species and their associated health hazards in various indoor environments worldwide.

Azole resistance in Aspergillus is emerging in European and Asian countries. As azoles are mainstay of therapy in the management of aspergillosis, azole resistance has serious implications in patient management. We report the emergence of resistance to triazoles in environmental Aspergillus fumigatus isolates in Iran. The TR34/L98H mutation was the only resistance mechanism. Overall 3.3% of the A. fumigatus isolates from hospital surroundings in Sari and Tehran had the same TR34/L98H STRAf genotype and were related to some resistant clinical and environmental TR34/L98H isolates from the Netherlands and India. It is emphasised that routine resistance surveillance studies focusing on environmental and clinical samples are warranted to yield the true prevalence of azole resistance in A. fumigatus in Iran.

In patients with preexisting lung disease, especially a cavity, Aspergillus can infect the surface of the cavity, causing chronic cavitary pulmonary aspergillosis (CCPA), and may form an aspergilloma, collectively called chronic pulmonary aspergillosis (CPA). In the present study, we assessed tuberculosis (TB) patients for CPA based on culture and serological methods. During a period of 1 year (from March 2013 to March 2014), we studied 124 patients with TB (94 with current TB and 30 with previous TB) at Masih Daneshvari Hospital in Tehran, Iran. Sputum specimens were analyzed by direct microscopic examination (DME) and fungal culture. The clinical and radiological features of all patients were recorded, to categorize the patients into CCPA and aspergilloma. All patients were screened for serum-specific IgG against A. fumigatus, by enzyme-linked immunosorbent assay (ELISA). Out of 124 patients with TB (66 male, age range: 10-91 years), 48 patients (38.7 %) exhibited residual cavities. Eighteen (14.5 %) patients had cavities with pleural thickening. A round-shaped mass lesion was detected in six patients (6.8 %). DME was positive in ten patients for septate fungal hyphae. A. fumigatus was grown from 14 samples. Fifty-five (44.3 %) cases were positive for serum-specific IgG against A. fumigatus. Of 124 patients with TB, 3 (2.4 %) met criteria for aspergilloma and 14 (11.3 %) for CCPA. CPA is a common clinical presentation in individuals with healed TB in Iran, as reported by previous studies from other countries.

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.

In recent decades the incidence of Candida endocarditis has increased dramatically. Despite the application of surgery and antifungal therapy, Candida endocarditis remains a life-threatening infection with significant morbidity and mortality. We report a 37-year-old male drug abuser presenting with high fever, chest pain, loss of appetite and cardiac failure. His echocardiography revealed mobile large tricuspid valve vegetations. Fungal endocarditis was confirmed by culturing of the resected vegetation showing mixed growth of Candida albicans and Candida tropicalis, although three consecutive blood cultures were negative for Candida species. Phenotypic identification was reconfirmed by sequencing of the internal transcribed spacer (ITS rDNA) region. The patient was initially treated with intravenous fluconazole (6 mg kg "1 per day), followed by 2 weeks of intravenous amphotericin B deoxycholate (1 mg kg "1 per day). Although MICs were low for both drugs, the patient's antifungal therapy combined with valve replacement failed, and he died due to respiratory failure.

An increasing number of reports have described the emergence of acquired resistance of Aspergillus fumigatus to azole compounds. The primary mechanism of resistance in clinical isolates is the mutation of the azole drug target enzyme, which is encoded by the cyp51A gene. The aim of this study was to evaluate the impact of silencing the cyp51A gene in azole-resistant A. fumigatus isolates. A 21-nucleotide small-interfering RNA (siRNA) was designed based on the cDNA sequence of the A. fumigatus cyp51A gene. After silencing the cyp51A gene in germinated conidia (15, 20, 25 and 50 nM), azole-resistant A. fumigatus was cultured on broth media and gene expression was analysed by measuring the cyp51A mRNA level using RT-PCR assay. Hyphae were successfully transfected by siRNA and expression of the cyp51A gene was significantly reduced by siRNA at the concentration of 50 nM (P ≤ 0.05). In addition, at this siRNA concentration, the minimum inhibitory concentration of itraconazole for the treated cells was decreased, compared with that for untreated control cells, from 16 to 4 μg/ml.

Mucormycosis is a life-threatening invasive fungal disease that affects a variety of patient groups. Although Mucorales are mostly opportunistic pathogens originating from soil or decaying vegetation, there are currently few data on prevalence of this group of fungi in the environment. The aim of the present study was to assess the prevalence and diversity of species of Mucorales from soil samples collected in France. Two grams of soil were homogenized in sterile saline and plated on Sabouraud dextrose agar and RPMI agar supplemented with itraconazole or voriconazole. Both media contained chloramphenicol and gentamicin. The plates were incubated at 35 ± 2 °C and checked daily for fungal growth for a maximum of 7 d. Mucorales were subcultured for purity. Each isolate was identified phenotypically and molecular identification was performed by ITS sequencing. A total of 170 soil samples were analyzed. Forty-one isolates of Mucorales were retrieved from 38 culture-positive samples. Among the recovered isolates, 27 Rhizopus arrhizus, 11 Mucor circinelloides, one Lichtheimia corymbifera, one Rhizopus microsporus and one Cunninghamella bertholletiae were found. Positive soil samples came from cultivated fields but also from other types of soil such as flower beds. Mucorales were retrieved from samples obtained in different geographical regions of France. Voriconazole-containing medium improved the recovery of Mucorales compared with other media. The present study showed that pathogenic Mucorales are frequently recovered from soil samples in France. Species diversity should be further analyzed on a larger number of soil samples from different geographic areas in France and in other countries.

We report two cases of chromoblastomycosis due to Fonsecaea pedrosoi and F. monophora in otherwise healthy Cuban males. Direct microscopic examination of biopsies revealed muriform cells, the hallmark of chromoblastomycosis. The suspected agents were recovered in culture, identified on the basis of morphological criteria and confirmed by sequencing of the internal transcribed spacer regions of rDNA. Final treatment consisted of surgical excision. The patients were successfully cured since there was no relapse after a follow-up of more than a year. In vitro antifungal susceptibility testing of both isolates showed that itraconazole and posaconazole had potent activity. High MICs of amphotericin B (2 μg/ml), fluconazole (>64 μg/ml), anidulafungin (8 μg/ml) and caspofungin (8 μg/ml) were found.