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Publications

21 Aug 2018
Hovhannisyan H., Gabaldón T. (2018) Transcriptome Sequencing Approaches to Elucidate Host–Microbe Interactions in Opportunistic Human Fungal Pathogens. In: . Current Topics in Microbiology and Immunology. Springer, Berlin, Heidelberg
29 May 2018
Candida auris, C. haemulonii, C. duobushaemulonii, and C. pseudohaemulonii are closely related and highly multidrug resistant yeast pathogens. The high cost and low accuracy of current diagnostics may underestimate their prevalence, especially in medical resource-limited regions. In this study, we used 172 C. auris stains and its relatives and 192 other fungal strains to establish and validate a novel multiplex end-point PCR. A prospective and a retrospective clinical screenings using this assay were further performed in China and Iran respectively. We identified the first isolate of C. pseudohaemulonii in China and the first isolate of C. haemulonii in Iran from 821 clinical isolates in total, without any false positive. Animal models of C. auris and C. haemulonii were established for validation. The overall positive rates of the assay for mice blood and tissue were 28.6 and 92.9%, respectively. Compared with previously developed assays, our assay is more available and affordable to the developing countries, and may contribute to a better understanding of the epidemiology of C. auris and its relatives in these regions.
24 Oct 2017
Aspergillus terreus infections are difficult to treat because of the intrinsic resistance to amphotericin B, and higher mortality compared to infections caused by other Aspergillus species. The aim of the present study was to determine the in vitro antifungal activity of amphotericin B and 11 comparators against clinical (n = 36) and environmental (n = 45) A. terreus isolates. In vitro antifungal susceptibility was performed using the CLSI M38‐A2 procedure. Amphotericin B exhibited the highest MICs (MIC range, 0.125‐4 μg/mL; MIC90, 2 μg/mL), followed by terbinafine (MIC range, 0.002‐1 μg/mL; MIC90, 1 μg/mL). Only one isolate (1/81) showed amphotericin B MIC above the epidemiologic cut‐off value (ECV; 4 μg/mL). None of the isolates had a MIC of ≥ ECV for voriconazole, itraconazole and posaconazole. The reasons for the difference in amphotericin B susceptibility patterns between studies remain unknown. The genetic and species diversity, clinical, environmental and ecological factors in Terrei section on various amphotericin B susceptibility profiles in different countries should be considered more as the main reasons associated with these differences.
17 Jul 2018
Mononuclear silver(I) complexes with 1,7-phenanthroline (1,7-phen), [Ag(NO3-O,O′) (1,7-phen-N7)2] (1) and [Ag(1,7-phen-N7)2]X, X = ClO4− (2), CF3SO3− (3), BF4− (4) and SbF6− (5) were synthesized and structurally characterized by NMR (1H and 13C), IR and UV–Vis spectroscopy and ESI mass spectrometry. The crystal structures of 1, 3 and 4 were determined by single-crystal X-ray diffraction analysis. In all these complexes, 1,7-phen coordinates to the Ag(I) ion in a monodentate fashion via the less sterically hindered N7 nitrogen atom. The investigation of the solution stability of 1–5 in DMSO revealed that they are sufficiently stable in this solvent at room temperature. Complexes 1–5 showed selectivity towards Candida spp. in comparison to bacteria, effectively inhibiting the growth of four different Candida species with minimal inhibitory concentrations (MIC) between 1.2 and 11.3 μM. Based on the lowest MIC values and the lowest cytotoxicity against healthy human fibroblasts with selectivity index of more than 30, the antifungal potential was examined in detail for the complex 1. It had the ability to attenuate C. albicans virulence and to reduce epithelial cell damage in the cell infection model. Induction of reactive oxygen species (ROS) response has been detected in C. albicans, with fungal DNA being one of the possible target biomolecules. The toxicity profile of 1 in the zebrafish model (Danio rerio) revealed improved safety and activity in comparison to that of clinically utilized silver(I) sulfadiazine.
18 Jul 2018
Candidemia caused by Candida albicans and Candida glabrata is constantly increasing, accompanied by a rising use of the few available antifungals. The widespread use of echinocandins and azoles for treatment of invasive candidemia has enhanced the development of antifungal-resistance resulting in an increasing health care problem. Hence, the rapid detection of resistant strains is required. This study aimed to evaluate the detection of C. albicans and C. glabrata strains resistant against caspofungin by MALDI Biotyper antibiotic susceptibility test- rapid assay (MBT ASTRA). This novel semi-quantitative technique facilitates the detection of caspofungin-resistant strains within 6 hours. MBT ASTRA results were compared to the data obtained by the Clinical and Laboratory Standards Institute guidelines (CLSI). Clinical isolates of C. albicans (n= 58) and C. glabrata (n= 57) were analysed by MBT ASTRA and CLSI microdilution. CLSI antifungal susceptibility test against caspofungin classified C. albicans isolates into 36 susceptible and 22 resistant strains, and C. glabrataisolates into 5 susceptible, 33 resistant and 19 intermediate, respectively. For C. albicans, the comparison of MBT ASTRA and the CLSI method revealed an excellent categorical agreement of 100%. Sensitivity and specificity of 94% and 80% between MBT ASTRA and CLSI were detected for C. glabrata strains, based on categorical agreement, respectively. In conclusion, the results obtained by MBT ASTRA indicated that this is a very promising approach for the rapid detection of candida isolates resistant to caspofungin.
25 Jan 2018
ABSTRACT: RNA molecules play important roles in virtually every cellular process. These functions are often mediated through the adoption of specific structures that enable RNAs to interact with other molecules. Thus, determining the secondary structures of RNAs is central to understanding their function and evolution. In recent years several sequencing-based approaches have been developed that ...
25 Jan 2018
ABSTRACT: Invasive candidiasis is among the most life-threatening infections in patients in intensive care units. Although Candida albicans is the leading cause of candidaemia, the incidence of Candida parapsilosis infections is also rising, particularly among the neonates. Due to differences in their biology, these species employ different antifungal resistance and virulence mechanisms and also ...
15 Jan 2018
ABSTRACT: Candida spp. are leading causes of opportunistic mycoses, including life-threatening hospital-borne infections, and novel antifungals, preferably aiming targets that have not been used before, are constantly needed. Hydrazone- and guanidine-containing molecules have shown a wide range of biological activities, including recently described excellent antifungal properties. In this study, ...
12 Jan 2018
ABSTRACT: Online sequence databases such as NCBI GenBank serve as a tremendously useful platform for researchers to share and reuse published data. However, submission systems lack control for errors such as organism misidentification, which once entered in the database can be propagated and mislead downstream analyses. Here we present an illustrating case of misidentification of Candida albicans ...
7 Nov 2017
ABSTRACT: Candida albicans is a dimorphic commensal fungus that causes severe oral infections in immunodeficient patients. Invasion of C. albicans hyphae into oral epithelium is an essential virulence trait. Interleukin-17 (IL-17) signaling is required for both innate and adaptive immunity to C. albicans . During the innate response, IL-17 is produced by γδ T cells and a poorly understood ...

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