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      In Vitro Activity of Manogepix (APX001A) and Comparators against Contemporary Molds: MEC Comparison and Preliminary Experience with Colorimetric MIC Determination

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      Antimicrobial Agents and Chemotherapy
      American Society for Microbiology

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          ABSTRACT

          Manogepix (APX001A) is the active moiety of the drug candidate fosmanogepix (APX001), currently in clinical development for the treatment of invasive fungal infections. We compared manogepix EUCAST minimum effective concentrations (MECs) to MICs of five comparators and CLSI MECs and MICs by a colorimetric method against contemporary molds. EUCAST susceptibility testing was performed for 161 isolates. Interlaboratory and intermethod reproducibility were determined by comparison with published manogepix MECs. Colorimetric MICs (measuring metabolic activity) were evaluated using three Aspergillus fumigatus isolates and one Aspergillus flavus isolate with four inocula at 24 to 48 h of incubation and 1 to 3 h 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt (XTT)/menadione (MEN) exposure. Manogepix modal MECs (range in mg/liter) against Aspergillus species were 0.03 to 0.06 (0.008 to 0.125) and unaffected by itraconazole resistance. Manogepix was as active against two Fusarium isolates but inactive against Trichophyton interdigitale, Lichtheimia ramosa, and Rhizomucor pusillus isolates (MECs >0.5). Modal MEC/MICs were ≥3 2-fold dilutions apart without overlapping ranges comparing manogepix with amphotericin B, isavuconazole, and voriconazole against Aspergillus isolates. Manogepix and posaconazole MECs/MICs correlated for Aspergillus niger (Pearson’s r = 0.711; P = 0.0044). The MEC at which 50% of the isolates tested are inhibited (MEC 50), mode, and MEC 90 values were within ±1 dilution in all cases compared with published EUCAST and CLSI data. The colorimetric method showed excellent agreement with the MECs when plates were inoculated with the lowest inoculum (1 × 10 2 CFU/ml to 2.5 × 10 2 CFU/ml), incubated for 24 h, and exposed for 1 to 3 h to XTT/MEN. Broad-spectrum in vitro activity of manogepix against clinically relevant molds was confirmed with excellent agreement across EUCAST and CLSI methods reported from experienced mycology laboratories. Colorimetric MIC determination warrants further investigation as a potential alternative that is less dependent on mycology expertise.

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          • Record: found
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          Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for Fungi.

          Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups.
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            • Record: found
            • Abstract: found
            • Article: not found

            Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes.

            We constructed nine sets of oligonucleotide primers on the basis of the results of DNA hybridization of cloned genes from Neurospora crassa and Aspergillus nidulans to the genomes of select filamentous ascomycetes and deuteromycetes (with filamentous ascomycete affiliations). Nine sets of primers were designed to amplify segments of DNA that span one or more introns in conserved genes. PCR DNA amplification with the nine primer sets with genomic DNA from ascomycetes, deuteromycetes, basidiomycetes, and plants revealed that five of the primer sets amplified a product only from DNA of the filamentous ascomycetes and deuteromycetes. The five primer sets were constructed from the N. crassa genes for histone 3, histone 4, beta-tubulin, and the plasma membrane ATPase. With these five primer sets, polymorphisms were observed in both the size of and restriction enzyme sites in the amplified products from the filamentous ascomycetes. The primer sets described here may provide useful tools for phylogenetic studies and genome analyses in filamentous ascomycetes and deuteromycetes (with ascomycete affiliations), as well as for the rapid differentiation of fungal species by PCR.
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              • Record: found
              • Abstract: found
              • Article: not found

              Internet-accessible DNA sequence database for identifying fusaria from human and animal infections.

              Because less than one-third of clinically relevant fusaria can be accurately identified to species level using phenotypic data (i.e., morphological species recognition), we constructed a three-locus DNA sequence database to facilitate molecular identification of the 69 Fusarium species associated with human or animal mycoses encountered in clinical microbiology laboratories. The database comprises partial sequences from three nuclear genes: translation elongation factor 1α (EF-1α), the largest subunit of RNA polymerase (RPB1), and the second largest subunit of RNA polymerase (RPB2). These three gene fragments can be amplified by PCR and sequenced using primers that are conserved across the phylogenetic breadth of Fusarium. Phylogenetic analyses of the combined data set reveal that, with the exception of two monotypic lineages, all clinically relevant fusaria are nested in one of eight variously sized and strongly supported species complexes. The monophyletic lineages have been named informally to facilitate communication of an isolate's clade membership and genetic diversity. To identify isolates to the species included within the database, partial DNA sequence data from one or more of the three genes can be used as a BLAST query against the database which is Web accessible at FUSARIUM-ID (http://isolate.fusariumdb.org) and the Centraalbureau voor Schimmelcultures (CBS-KNAW) Fungal Biodiversity Center (http://www.cbs.knaw.nl/fusarium). Alternatively, isolates can be identified via phylogenetic analysis by adding sequences of unknowns to the DNA sequence alignment, which can be downloaded from the two aforementioned websites. The utility of this database should increase significantly as members of the clinical microbiology community deposit in internationally accessible culture collections (e.g., CBS-KNAW or the Fusarium Research Center) cultures of novel mycosis-associated fusaria, along with associated, corrected sequence chromatograms and data, so that the sequence results can be verified and isolates are made available for future study.
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                Author and article information

                Contributors
                (View ORCID Profile)
                Journal
                Antimicrobial Agents and Chemotherapy
                Antimicrob Agents Chemother
                American Society for Microbiology
                0066-4804
                1098-6596
                July 22 2020
                July 22 2020
                June 08 2020
                : 64
                : 8
                Article
                10.1128/AAC.00730-20
                7526828
                32513793
                65341dff-1706-4a2e-a9a1-9355b7725aad
                © 2020
                History

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