scholarly journals Scedosporium spp. from Clinical Setting in Argentina, with the Proposal of the New Pathogenic Species Scedosporium americanum

2021 ◽  
Vol 7 (3) ◽  
pp. 160
Author(s):  
Ruben A. Abrantes ◽  
Nicolás Refojo ◽  
Alejandra I. Hevia ◽  
Julián Fernández ◽  
Guillermina Isla ◽  
...  
Keyword(s):  
Antifungal Drugs ◽  
Phenotypic Characterization ◽  
Clinical Samples ◽  
Phylogenetic Study ◽  
Reference Laboratory ◽  
In Vitro Susceptibility ◽  
Wide Range ◽  
Human Infections ◽  
Scedosporium Species

Species of the genus Scedosporium (family Microascaceae, phylum Ascomycota) are responsible for a wide range of opportunistic human infections, and have a low susceptibility to most antifungal drugs. It is well known that the pattern of Scedosporium species distribution varies according to geographic region. To assess the diversity of Scedosporium species in Argentina involved in human infections, we carried out a retrospective study reviewing 49 strains from clinical samples sent for diagnosis to the National Clinical Mycology Reference Laboratory between 1985 and 2019. Then, a phenotypic characterization, a phylogenetic study and and in vitro susceptibility test to antifungals were carried out. An analysis of combined nucleotide sequences dataset of the internal transcribed spacer of the ribosomal DNA (ITS) and of a fragment of the β-tubulin gene (BT2) demonstrated that 92 % of the strains belonged to the species S. boydii, S. apiospermum and S. angustum, all them pertaining to S. apiospermum species complex. However, two strains (4%) were identified as S. aurantiacum, a species never reported in clinical settings in the Americas’. Surprisingly, one of them displayed a polycytella-like conidiogenesis, up to date only reported for S. apiospermum. In addition, the strain DMic 165285 was phylogenetically located far away from the rest of the species, so is proposed as the novel species Scedosporium americanum. On the other hand, from all seven antifungals tested, voriconazole and posaconazole were the most active drugs against Scedosporium spp.

scholarly journals A revision of malbranchea-like fungi from clinical specimens in the United States of America reveals unexpected novelty

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ernesto Rodríguez-Andrade ◽  
José F. Cano-Lira ◽  
Nathan Wiederhold ◽  
Alba Pérez-Cantero ◽  
Josep Guarro ◽  
...  
Keyword(s):  
United States Of America ◽  
The United States ◽  
New Combination ◽  
Phylogenetic Study ◽  
Reference Laboratory ◽  
In Vitro Activity ◽  
The Usa ◽  
Human Infections ◽  
In Vitro Antifungal Activity

ABSTRACTThe fungi of the order Onygenales can cause important human infections; however, their taxonomy and worldwide occurrence is still little known. We have studied and identified a representative number of clinical fungi belonging to that order from a reference laboratory in the USA. A total of 22 strains isolated from respiratory tract (40%) and human skin and nails (27.2%) showed a malbranchea-like morphology. Six genera were phenotypically and molecularly identified, i.e. Auxarthron/Malbranchea (68.2%), Arachnomyces (9.1%), Spiromastigoides (9.1%), and Currahmyces (4.5%), and two newly proposed genera (4.5% each). Based on the results of the phylogenetic study, we synonymized Auxarthron with Malbranchea, and erected two new genera: Pseudoarthropsis and Pseudomalbranchea. New species proposed are: Arachnomyces bostrychodes, A. graciliformis, Currahmyces sparsispora, Malbranchea gymnoascoides, M. multiseptata, M. stricta, Pseudoarthropsis crassispora, Pseudomalbranchea gemmata, and Spiromastigoides geomycoides, along with a new combination for Malbranchea gypsea. The echinocandins showed the highest in vitro antifungal activity against the studied isolates, followed by terbinafine and posaconazole; in contrast, amphotericin B, fluconazole, itraconazole and 5-fluorocytosine were less active or lacked in vitro activity against these fungi.

scholarly journals Rare malbranchea-like fungal isolates from clinical specimens in United States of America.

2021 ◽  
Author(s):  
Ernesto Rodríguez-Andrade ◽  
Jose F. Cano-Lira ◽  
Nathan Wiederhold ◽  
Alba Perez-Cantero ◽  
Josep Guarro ◽  
...  
Keyword(s):  
United States Of America ◽  
New Combination ◽  
Phylogenetic Study ◽  
Reference Laboratory ◽  
New Genera ◽  
Clinical Specimens ◽  
Fungal Isolates ◽  
The Usa ◽  
Human Infections

Abstract The fungi of the order Onygenales can cause important human infections; however, their taxonomy and worldwide occurrence is still little known. We have studied and identified a representative number of clinical fungi belonging to that order from a reference laboratory in the USA. A total of twenty-two strains isolated from respiratory tract (40 %) and human skin and nails (27.2 %) showed a malbranchea-like morphology. Six genera were phenotypically and molecularly identified, i.e. Auxarthron/Malbranchea (68.2 %), Arachnomyces (9.1 %), Spiromastigoides (9.1 %), and Currahmyces (4.5 %), and two newly proposed genera (4.5 % each). Based on the results of the phylogenetic study, we synonymysed Auxarthron to Malbranchea, and erected two new genera: Pseudoarthropsis and Pseudomalbranchea. New species are proposed: Arachnomyces bostrychodes, A. graciliformis, Currahmyces sparsispora, Malbranchea gymnoascoidea, M. multiseptata, M. stricta, Pseudoarthropsis crassispora, Pseudomalbranchea gemmata and Spiromastigoides geomyces, along with a new combination for Malbranchea gypsea. The echinocandins showed the highest in vitro antifungal activity against the studied isolates, followed by terbinafine and posaconazole; in contrast, amphotericin B, fluconazole, itraconazole and 5-fluorocytosine were less active or lacked in vitro activity against these fungi.

scholarly journals Multilocus Phylogeny and Antifungal Susceptibility of Aspergillus Section Circumdati from Clinical Samples and Description of A. pseudosclerotiorum sp. nov.

2017 ◽  
Vol 55 (3) ◽  
pp. 947-958 ◽  
Author(s):  
J. P. Z. Siqueira ◽  
D. A. Sutton ◽  
J. Gené ◽  
D. García ◽  
N. Wiederhold ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Amphotericin B ◽  
Antifungal Susceptibility ◽  
The United States ◽  
Antifungal Drugs ◽  
Clinical Samples ◽  
Phylogenetic Study ◽  
Species Identity ◽  
Content Type

ABSTRACTA multilocus phylogenetic study was carried out to assess species identity of a set of 34 clinical isolates fromAspergillussectionCircumdatifrom the United States and to determine theirin vitroantifungal susceptibility against eight antifungal drugs. The genetic markers used were the internal transcribed spacer (ITS) region, and fragments of the beta-tubulin (BenA), calmodulin (CaM), and RNA polymerase II second largest subunit (RPB2) genes. The drugs tested were amphotericin B, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, micafungin, and terbinafine. The most common species sampled wasA. westerdijkiae(29.4%), followed by a novel species, which was described here asA. pseudosclerotiorum(23.5%). Other species identified wereA. sclerotiorum(17.6%),A. ochraceus(8.8%),A. subramanianii(8.8%), andA. insulicolaandA. ochraceopetaliformis, with two isolates (5.9%) of each. The drugs that showed the most potent activity were caspofungin, micafungin, and terbinafine, while amphotericin B showed the least activity.

scholarly journals In Vitro Synergistic Interactions of Isavuconazole and Echinocandins against Candida auris

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 355
Author(s):  
Unai Caballero ◽  
Sarah Kim ◽  
Elena Eraso ◽  
Guillermo Quindós ◽  
Valvanera Vozmediano ◽  
...  
Keyword(s):  
Interaction Model ◽  
Antifungal Drugs ◽  
Health Concern ◽  
Candida Auris ◽  
Fungistatic Activity ◽  
Drug Concentrations ◽  
Low Concentrations ◽  
Wide Range ◽  
Time Kill

Candida auris is an emergent fungal pathogen that causes severe infectious outbreaks globally. The public health concern when dealing with this pathogen is mainly due to reduced susceptibility to current antifungal drugs. A valuable alternative to overcome this problem is to investigate the efficacy of combination therapy. The aim of this study was to determine the in vitro interactions of isavuconazole with echinocandins against C. auris. Interactions were determined using a checkerboard method, and absorbance data were analyzed with different approaches: the fractional inhibitory concentration index (FICI), Greco universal response surface approach, and Bliss interaction model. All models were in accordance and showed that combinations of isavuconazole with echinocandins resulted in an overall synergistic interaction. A wide range of concentrations within the therapeutic range were selected to perform time-kill curves. These confirmed that isavuconazole–echinocandin combinations were more effective than monotherapy regimens. Synergism and fungistatic activity were achieved with combinations that included isavuconazole in low concentrations (≥0.125 mg/L) and ≥1 mg/L of echinocandin. Time-kill curves revealed that once synergy was achieved, combinations of higher drug concentrations did not improve the antifungal activity. This work launches promising results regarding the combination of isavuconazole with echinocandins for the treatment of C. auris infections.

scholarly journals Comparison of NCCLS and 3-(4,5-Dimethyl-2-Thiazyl)-2,5-Diphenyl-2H-Tetrazolium Bromide (MTT) Methods of In Vitro Susceptibility Testing of Filamentous Fungi and Development of a New Simplified Method

2000 ◽  
Vol 38 (8) ◽  
pp. 2949-2954 ◽  
Author(s):  
Joseph Meletiadis ◽  
Jacques F. G. M. Meis ◽  
Johan W. Mouton ◽  
J. Peter Donnelly ◽  
Paul E. Verweij
Keyword(s):  
Filamentous Fungi ◽  
Clinical Laboratory ◽  
Colorimetric Method ◽  
Antifungal Drugs ◽  
National Committee ◽  
In Vitro Susceptibility ◽  
Initial Inoculum ◽  
Tetrazolium Bromide ◽  
Mtt Method

The susceptibility of 30 clinical isolates belonging to six different species of filamentous fungi (Aspergillus fumigatus, Aspergillus flavus, Scedosporium prolificans, Scedosporium apiospermum, Fusarium solani, and Fusarium oxysporum) was tested against six antifungal drugs (miconazole, voriconazole, itraconazole, UR9825, terbinafine, and amphotericin B) with the microdilution method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) (M38-P). The MICs were compared with the MICs obtained by a colorimetric method measuring the reduction of the dye 3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) to formazan by viable fungi. The levels of agreement between the two methods were 96 and 92% for MIC-0 (clear wells) and MIC-1 (75% growth reduction), respectively. The levels of agreement were always higher for Aspergillus spp. (97% ± 2.5%), followed byScedosporium spp. (87% ± 10.3%) and Fusariumspp. (78% ± 7.8%). The NCCLS method was more reproducible than the MTT method: 98 versus 95% for MIC-0 and 97 versus 90% for MIC-1. However, the percentage of hyphal growth as determined visually by the NCCLS method showed several discrepancies when they were compared with the percentages of MTT reduction. A new simplified assay that incorporates the dye MTT with the initial inoculum and in which the fungi are incubated with the dye for 48 h or more was developed, showing comparable levels of agreement and reproducibility with the other two methods. Furthermore, the new assay was easier to perform and more sensitive than the MTT method.

In vitro susceptibility of 188 clinical and environmental isolates of Aspergillus flavus for the new triazole isavuconazole and seven other antifungal drugs

Mycoses ◽  
2011 ◽  
Vol 54 (5) ◽  
pp. e583-e589 ◽  
Author(s):  
M. R. Shivaprakash ◽  
Erik Geertsen ◽  
Arunaloke Chakrabarti ◽  
Johan W. Mouton ◽  
Jacques F. Meis
Keyword(s):  
Aspergillus Flavus ◽  
Antifungal Drugs ◽  
Environmental Isolates ◽  
In Vitro Susceptibility

scholarly journals Aspergillus calidoustus sp. nov., Causative Agent of Human Infections Previously Assigned to Aspergillus ustus

2008 ◽  
Vol 7 (4) ◽  
pp. 630-638 ◽  
Author(s):  
János Varga ◽  
Jos Houbraken ◽  
Henrich A. L. Van Der Lee ◽  
Paul E. Verweij ◽  
Robert A. Samson
Keyword(s):  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Protein Coding ◽  
Coding Regions ◽  
Aspergillus Ustus ◽  
Invasive Infections ◽  
Human Infections ◽  
Immunocompromised Hosts ◽  
A New Species

ABSTRACT Aspergillus ustus is a relatively rare human pathogen causing invasive infections in immunocompromised hosts. In this study isolates originating from clinical and other sources have been examined using molecular, morphological, and physiological approaches to clarify their species assignment. Phylogenetic analysis of partial β-tubulin, calmodulin, actin, and intergenic transcribed spacer sequences indicated that none of the clinical isolates recognized previously as A. ustus belongs to this species. All but two of these isolates formed a well-defined clade related to A. pseudodeflectus based on sequence analysis of protein-coding regions. Morphological and physiological examination of these isolates indicated that they are able to grow above 37°C, in contrast with A. ustus isolates, and give a positive Ehrlich reaction, in contrast with related species including A. granulosus, A. ustus, and A. pseudodeflectus. These isolates are proposed as a new species, A. calidoustus. Antifungal susceptibility testing showed that this species has decreased susceptibilities to several antifungal drugs. The triazoles are inactive in vitro, including the new azole posaconazole.

scholarly journals In Vitro Antifungal Activities of a Series of Dication-Substituted Carbazoles, Furans, and Benzimidazoles

1998 ◽  
Vol 42 (10) ◽  
pp. 2503-2510 ◽  
Author(s):  
Maurizio Del Poeta ◽  
Wiley A. Schell ◽  
Christine C. Dykstra ◽  
Susan K. Jones ◽  
Richard R. Tidwell ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Fusarium Solani ◽  
Antifungal Agents ◽  
Antifungal Drugs ◽  
Inhibitory Compounds ◽  
Wide Range ◽  
Fluconazole Resistant ◽  
Resistant Strains

ABSTRACT Aromatic dicationic compounds possess antimicrobial activity against a wide range of eucaryotic pathogens, and in the present study an examination of the structures-functions of a series of compounds against fungi was performed. Sixty-seven dicationic molecules were screened for their inhibitory and fungicidal activities againstCandida albicans and Cryptococcus neoformans. The MICs of a large number of compounds were comparable to those of the standard antifungal drugs amphotericin B and fluconazole. Unlike fluconazole, potent inhibitory compounds in this series were found to have excellent fungicidal activities. The MIC of one of the most potent compounds against C. albicans was 0.39 μg/ml, and it was the most potent compound against C. neoformans (MIC, ≤0.09 μg/ml). Selected compounds were also found to be active againstAspergillus fumigatus, Fusarium solani,Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. Since some of these compounds have been safely given to animals, these classes of molecules have the potential to be developed as antifungal agents.

In vitro susceptibility of Aspergillus and Fusarium associated with equine keratitis to new antifungal drugs

2020 ◽  
Vol 23 (5) ◽  
pp. 918-922 ◽  
Author(s):  
Darby Roberts ◽  
Henry Van T. Cotter ◽  
Marc Cubeta ◽  
Brian C. Gilger
Keyword(s):  
Antifungal Drugs ◽  
In Vitro Susceptibility

scholarly journals The Needs for Developing Experiments on Reservoirs in Hantavirus Research: Accomplishments, Challenges and Promises for the Future

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 664 ◽  
Author(s):  
Madrières ◽  
Castel ◽  
Murri ◽  
Vulin ◽  
Marianneau ◽  
...  
Keyword(s):  
Evolutionary Ecology ◽  
Experimental Studies ◽  
Mortality Rates ◽  
Wide Range ◽  
The Future ◽  
The Subject ◽  
The Many ◽  
Human Infections ◽  
The Relationship

Due to their large geographic distribution and potential high mortality rates in human infections, hantaviruses constitute a worldwide threat to public health. As such, they have been the subject of a large array of clinical, virological and eco-evolutionary studies. Many experiments have been conducted in vitro or on animal models to identify the mechanisms leading to pathogenesis in humans and to develop treatments of hantavirus diseases. Experimental research has also been dedicated to the understanding of the relationship between hantaviruses and their reservoirs. However, these studies remain too scarce considering the diversity of hantavirus/reservoir pairs identified, and the wide range of issues that need to be addressed. In this review, we present a synthesis of the experimental studies that have been conducted on hantaviruses and their reservoirs. We aim at summarizing the knowledge gathered from this research, and to emphasize the gaps that need to be filled. Despite the many difficulties encountered to carry hantavirus experiments, we advocate for the need of such studies in the future, at the interface of evolutionary ecology and virology. They are critical to address emerging areas of research, including hantavirus evolution and the epidemiological consequences of individual variation in infection outcomes.

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