Molecular identification, phylogenetic analysis and antifungal susceptibility patterns of Aspergillusnidulans complex and Aspergillusterreus complex isolated from clinical specimens.

OBJECTIVE: Aspergillus sections Terrei and Nidulantes are the less common causes of invasive aspergillosis and pulmonary aspergillosis (PA) in immunocompromised patients when compared to A. fumigatus and A. flavus. Identifying these fungi as the infectious agent is crucial because of the resistance to amphotericin B (AMB) and increased lethality. The aim of this study was to identify the molecular status, evaluate the genetic diversity and examine the antifungal susceptibility profile of the uncommon Aspergillus species. Forty-five uncommon Aspergillus species were identified based on the microscopic and macroscopic criteria. Then, the molecular identification was performed using the sequencing beta tubulin (benA) gene. In vitro antifungal susceptibility to amphotericin B (AMB), itraconazole (ITC), ravuconazole (RAV), voriconazole (VRC), caspofungin (CFG) isavuconazole (ISA) and posaconazole (POS) test was performed according to the CLSI M38-A2 guidelines. RESULTS: A. terreus was the most species detected, followed by A. nidulans, A. latus, A.ochraceus, and A. citrinoterreus, respectively. The analysis of the benA gene showed the presence of 12 distinct genotypes among the A. terreus isolates. The other species did not show any intraspecies variation. CFG exhibited the lowest MEC50/MIC50 (0.007µg/mL), followed by POS (0.125µg/mL), VRC, ITC, ISA (0.25µg/mL), RAV (0.5µg/mL), and AMB (8µg/mL). Among all the isolates, only 15.5% (7/45) were susceptible to AMB. CONCLUSION: Antifungal susceptibility pattern of the uncommon Aspergillus species is useful to improve patient management and increase knowledge concerning the local epidemiology. Moreover, this information is necessary when an outbreak dealing with drug-resistant infections occurs.

Successful control of exacerbation of Allergic Bronchopulmonary Aspergillosis due to Aspergillus terreus in a cystic fibrosis patient with short-term adjunctive therapy with voriconazole: A case report.

A 12-year-old boy with cystic fibrosis (CF) and a history of glucocorticoid-dependent allergic bronchopulmonary aspergillosis (ABPA) was referred to our hospital. The ABPA was diagnosed when he was 8 years old and he had been treated with several course of oral glucocorticoids for recurrent exacerbations. He was readmitted when aged 12 with a history of worsening shortness of breath and chest tightness. A recurrence of ABPA was diagnosed based on eosinophilia and elevation of Aspergillusspecific IgE and IgG, and total IgE. Thoracic high-resolution computed tomography (HRCT) showed central bronchiectasis with parenchymal infiltrates. The treatment started with itraconazole and oral corticosteroid. After 2 months of treatment, he was re-admitted to the hospital due to a progressive worsening of respiratory symptoms. Chest HRCT revealed the a sub segmental atelectasis in the left lung. Microscopic examination of sputum and BAL samples demonstrated septate hyphae consistent with Aspergillus species. Sputum and BAL culture yielded Aspergillus ochraceus and Aspergillus terreus, which were both sensitive to itraconazole and voriconazole. The treatment was switched to voriconazole and the patient showed significant clinical, serological and mycological improvement after three months. This case shows that voriconazole may be used as an alternative for treatment of ABPA due to Aspergillus terreus.

In vitro antifungal susceptibility of clinical species belonging to Aspergillus genus and Rhizopus oryzae.

OBJECTIVE: Among filamentous fungal pathogens, Aspergillus spp. and zygomycetes account for highest rates of morbidity and mortality among immunocompromised patients. Recently developed antifungal drugs offer the potential to improve management and therapeutic outcomes of fungal infections. The aim of this study was to analyse the in vitro activities of voriconazole, itraconazole, amphotericin B and caspofungin against clinical isolates of Aspergillus spp. and Rhizopus oryzae. MATERIAL AND METHODS: The in vitro antifungal susceptibility of 54 isolates belonging to different clinical isolates of Aspergillus spp. and R. oryzae was tested for four antifungal agents using a microdilution reference method (CLSI, M38-A2). All isolates were identified by typical colony and microscopic characteristics, and also characterized by molecular methods. RESULTS: Caspofungin (MEC range: 0.008-0.25 and MEC50: 0.0023µg/mL) was the most active drug in vitro against Aspergillus spp., followed by voriconazole (MIC range: 0.031-8 and MIC50: 0.5µg/mL), itraconazole (MIC range: 0.031-16 and MIC50: 0.25µg/mL), and amphotericin B (MIC range: 0.125-4 and MIC50: 0.5µg/mL), in order of decreasing activity. The caspofungin, voriconazole, and itraconazole demonstrated poor in vitro activity against R. oryzae isolates evaluated, followed by amphotericin B. CONCLUSION: This study demonstrates that caspofungin had good antifungal activity and azole agents had better activity than amphotericin B against Aspergillus species. Although, azole drugs are considered ineffective against R. oryzae. This result is just from a small scale in vitro susceptibility study and we did not take other factors into consideration.