A Whole Genome Sequencing-Based Approach to Track down Genomic Variants in Itraconazole-Resistant Species of Aspergillus from Iran.

The antifungal resistance in non-fumigatus Aspergillus spp., as well as Aspergillus fumigatus, poses a major therapeutic challenge which affects the entire healthcare community. Mutation occurrence of cyp51 gene paralogs is the major cause of azole resistance in Aspergillus spp. To obtain a full map of genomic changes, an accurate scan of the entire length of the Aspergillus genome is necessary. In this study, using whole genome sequencing (WGS) technique, we evaluated the mutation in cyp51A, cyp51B, Cdr1B, AtrR, Hmg1, HapE and FfmA genes in different clinical isolates of Aspergillus fumigatus, Aspergillus niger, Aspergillus tubingensis, Aspergillus welwitschiae and Aspergillus terreus which responded to minimum inhibitory concentrations of itraconazole above 16 µg mL-1. We found different nonsynonymous mutations in the cyp51A, cyp51B, Cdr1B, AtrR, Hmg1, HapE and FfmA gene loci. According to our findings, Aspergillus species isolated from different parts of the world may represent different pattern of resistance mechanisms which may be revealed by WGS.

In vitro activity of 23 antifungal drugs against 54 clinical and environmental Aspergillus oryzae isolates.

The treatment of invasive aspergillosis caused by cryptic species remains a challenge due to the lack of randomised clinical trials and investigation of the efficacy and safety of different therapeutic strategies. We aimed to evaluate the in vitro activity of 23 conventional and new antifungal drugs against 54 clinical and environmental Aspergillus oryzae isolates by using the Clinical and Laboratory Standards Institute (CLSI) standard M38-A3. The lowest geometric mean MIC values were found for luliconazole and lanoconazole (0.001 µg/ml), followed by anidulafungin (0.104 µg/ml), posaconazole (0.15 µg/ml), itraconazole (0.37 µg/ml), efinaconazole (0.5 µg/ml), voriconazole (0.51 µg/ml), tavaborole (0.72 µg/ml), and amphotericin B (0.79 µg/ml). In contrast, ketoconazole, terbinafine, econazole, tioconazole, ravuconazole, miconazole, nystatin, clotrimazole, griseofulvin, sertaconazole, natamycin, tolnaftate, and fluconazole had no or low activity. Further studies are required to determine how well this in vitro activity translates into in vivo efficacy.

Molecular identification and antifungal susceptibility of clinically relevant and cryptic species of Aspergillus sections Flavi and Nigri.

Introduction. Aspergillus sections Flavi and Nigri comprise clinically relevant and cryptic species that differ significantly in drug susceptibility, meaning that effective treatment depends on correct species identification.Hypothesis/Gap Statement. There are no comprehensive data for molecular identification and antifungal susceptibility testing (AFST) of clinically relevant and cryptic species of Aspergillus sections Flavi and Nigri as the main agents of invasive and non-invasive aspergillosis in Iran. We aimed to perform molecular identification and AFST of 213 clinical Aspergillus isolates belonging to sections Flavi and Nigri. Molecular identification of isolates was performed using sequencing of the ß-tubulin gene and in vitro AFST was conducted according to the Clinical and Laboratory Standards Institute (CLSI) M38-A3 guidelines.Results. The most common isolates in sections Flavi and Nigri were Aspergillus flavus (110/113, 97.3 %) and Aspergillus tubingensis (49/100, 49.0 %), respectively. A total of 62/213 (29.1 %) isolates belonging to cryptic species were identified; among them, A. tubingensis was the most prevalent (49/62, 79.0%). Aspergillus flavus and A. niger isolates that responded to the minimum inhibitory concentrations (MICs) of itraconazole above the epidemiological cutoff values were the most frequently detected: 8/110 (7.3 %) and 3/41 (7.3 %), respectively. In section Flavi, Aspergillus alliaceus responded to amphotericin B at a high MIC (>16 µg mL-1) and in section Nigri, one of the three Aspergillus luchuensis/awamori isolates responded to itraconazole at an MIC >16 µg ml-1. Interestingly, for all Aspergillus welwitschiae isolates, the MIC50 and MIC90 of itraconazole were both 16 µg ml-1.Conclusion. A considerable presence of A. flavus and A. niger isolates showing non-wild-type responses to azoles in clinical cases of aspergillosis indicates the importance of classifying clinical Aspergillus isolates at the species level and performing antifungal susceptibility testing on the isolates, which would ensure appropriate treatment.

Development of RFLP method for rapid differentiation of Aspergillus flavus and Aspergillus oryzae, two species with high importance in clinical and food microbiology.

Aspergillus flavus and Aspergillus oryzae, two species of Aspergillus section Flavi, are of utmost significance in health, medicine, biotechnology, and foods industries. The methods currently used in mycology for the discrimination of these two closely related species were unable to definitively and rapidly distinguish. The present study aimed to develop a restriction fragment length polymorphism (RFLP) test based on the cyp51A gene to discriminate between A. flavus and A. oryzae. The cyp51A gene sequences of A. flavus and A. oryzae reference strains were amplified using the specific primers CYP51AF and CYP51AR. The polymerase chain reaction (PCR) products were subjected to digestion with a restriction enzyme, HincII. The polymerase chain reaction (PCR)- RFLP test created specific patterns for standard strains, as well as clinical and environmental A. flavus and A. oryzae isolates. The one-enzyme PCR-RFLP test on the cyp51A gene designed in the present study is a remarkably simple, reliable, and low-cost method for the accurate and rapid differentiation of A. flavus and A. oryzae isolated from clinical and environmental samples.

Differentiation of Aspergillus flavus from Aspergillus oryzae Targeting the cyp51A Gene.

Aspergillus flavus is one of the most important agents of invasive and non-invasive aspergillosis, especially in tropical and subtropical regions of the world, including Iran. Aspergillus oryzae is closely related to A. flavus, and it is known for its economic importance in traditional fermentation industries. Reports of infection due to A. oryzae are scarce. Several studies reported that differentiating these two species in clinical laboratories is not possible using MALDI-TOF or by targeting fungal barcode genes, such as Internal Transcribed Spacer (ITS) and ß-tubulin (benA). The species-level identification of causative agents and the determination of antifungal susceptibility patterns can play significant roles in the outcome of aspergillosis. Here, we aimed to investigate the discriminatory potential of cyp51A PCR-sequencing versus that of the ITS, benA and calmodulin (CaM) genes for the differentiation of A. flavus from A. oryzae. In a prospective study investigating the molecular epidemiology of A. flavus in Iran between 2008 and 2018, out of 200 clinical isolates of A. flavus, 10 isolates showed >99% similarity to both A. flavus and A. oryzae. Overall, the ITS, ß-tubulin and CaM genes did not fulfil the criteria for differentiating these 10 isolates. However, the cyp51A gene showed promising results, which warrants further studies using a larger set of isolates from more diverse epidemiological regions of the world.

Recent Advances in Genome Editing Tools in Medical Mycology Research.

Manipulating fungal genomes is an important tool to understand the function of target genes, pathobiology of fungal infections, virulence potential, and pathogenicity of medically important fungi, and to develop novel diagnostics and therapeutic targets. Here, we provide an overview of recent advances in genetic manipulation techniques used in the field of medical mycology. Fungi use several strategies to cope with stress and adapt themselves against environmental effectors. For instance, mutations in the 14 alpha-demethylase gene may result in azole resistance in Aspergillusfumigatus strains and shield them against fungicide's effects. Over the past few decades, several genome editing methods have been introduced for genetic manipulations in pathogenic fungi. Application of restriction enzymes to target and cut a double-stranded DNA in a pre-defined sequence was the first technique used for cloning in Aspergillus and Candida. Genome editing technologies, including zinc-finger nucleases (ZFNs) and transcriptional activator-like effector nucleases (TALENs), have been also used to engineer a double-stranded DNA molecule. As a result, TALENs were considered more practical to identify single nucleotide polymorphisms. Recently, Class 2 type II Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas9 technology has emerged as a more useful tool for genome manipulation in fungal research.

The impact of COVID-19 pandemic on AIDS-related mycoses and fungal neglected tropical diseases: Why should we worry?

The World Health Organization (WHO) considers mycetoma, chromoblastomycosis, and paracoccidioidomycosis to be fungal neglected tropical diseases (FNTDs). Depending on climatic, cultural, and economic contexts, these diseases have a similar geographical distribution as many other diseases, particularly tuberculosis (TB) and malaria, but are often less targeted by the national and many international healthcare systems. Another subgroup of fungal infections, such as candidiasis, cryptococcosis, pneumocystosis, histoplasmosis, and to a lesser extent, aspergillosis, are known as AIDS-related mycoses. Although antiretroviral therapy (ART) has been able to decrease the mortality rate of these diseases, particularly cryptococcosis, the disproportionately low distribution of funds to their diagnosis and treatment remains an obstacle in saving and improving the lives of patients affected. A new wave of viral diseases dubbed the Coronavirus Disease 2019 (COVID-19) hit the world at the end of 2019. Due to progressive symptoms and high mortality rates of COVID-19 compared to fungal infections, particularly the FNTDs, funding is currently allocated predominantly for diagnostic and therapeutic research on COVID-19. As a result, advances in FNTDs and AIDS-related mycosis care are considerably reduced. This paper explores the association between COVID-19, FNTDs, and AIDS-related mycoses with a predictive perspective.