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  • 11
    In: PLOS Biology, Public Library of Science (PLoS), Vol. 19, No. 3 ( 2021-3-15), p. e3000957-
    Abstract: A forward genetic screening approach identified orf19.2500 as a gene controlling Candida albicans biofilm dispersal and biofilm detachment. Three-dimensional (3D) protein modeling and bioinformatics revealed that orf19.2500 is a conserved mitochondrial protein, structurally similar to, but functionally diverged from, the squalene/phytoene synthases family. The C . albicans orf19.2500 is distinguished by 3 evolutionarily acquired stretches of amino acid inserts, absent from all other eukaryotes except a small number of ascomycete fungi. Biochemical assays showed that orf19.2500 is required for the assembly and activity of the N A D H u biquinone oxidoreductase Complex I (CI) of the respiratory electron transport chain (ETC) and was thereby named NDU1 . NDU1 is essential for respiration and growth on alternative carbon sources, important for immune evasion, required for virulence in a mouse model of hematogenously disseminated candidiasis, and for potentiating resistance to antifungal drugs. Our study is the first report on a protein that sets the Candida -like fungi phylogenetically apart from all other eukaryotes, based solely on evolutionary “gain” of new amino acid inserts that are also the functional hub of the protein.
    Type of Medium: Online Resource
    ISSN: 1545-7885
    Language: English
    Publisher: Public Library of Science (PLoS)
    Publication Date: 2021
    detail.hit.zdb_id: 2126773-X
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  • 12
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2020
    In:  Open Forum Infectious Diseases Vol. 7, No. Supplement_1 ( 2020-12-31), p. S420-S420
    In: Open Forum Infectious Diseases, Oxford University Press (OUP), Vol. 7, No. Supplement_1 ( 2020-12-31), p. S420-S420
    Abstract: Mucormycosis is a life-threatening infection that predominantly occurs in immunocompromised hosts. Liposomal amphotericin B (L-AMB) and isavuconazole (ISAV) are commonly used antifungal drugs to treat mucormycosis. However, the efficacy of combination therapy of L-AMB + ISAV compared to monotherapy is unknown. We used an immunosuppressed mouse model of pulmonary mucormycosis to compare the efficacy of L-AMB + ISAV vs. either drug alone. Methods ICR mice were immunosuppressed with cyclophosphamide (200 mg/kg) and cortisone acetate (500 mg/kg) on Days -2, +3, and +8 relative to intratracheal infection with 2.5 x 105 cells of Rhizopus delemar 99-880, or 2.5 x 106 cells of Mucor circinelloides. Treatment with L-AMB (10 mg/kg, given intravenously qd), ISAV (56 mg/kg, by oral gavage TID), or a combination of both started 8 h post-infection and continued through day +4. Placebo mice received vehicle control. Survival studies through day +21 and tissue fungal burden (by conidial equivalent [CE] using qPCR) on Day +4, served as primary and secondary endpoints. Results For mice (n=20) infected with R. delemar, L-AMB and ISAV equally prolonged median survival time and enhanced survival vs. placebo (19 and 16 days for L-AMB and ISAV, respectively, and overall survival of 50% for either drug alone, vs. 9 days and 5% overall survival for placebo, P & lt; 0.002 for either drug vs. placebo by Log Rank test). Importantly, combination treatment enhanced median survival time ( & gt;21 days) and resulted in an overall survival of 80% (P & lt; 0.05 vs. all treatments). Both antifungal drugs reduced tissue fungal burden of mice (n=10) lungs and brain by ~1.0-2.0 log vs. placebo-treated mice (P & lt; 0.02 by Wilcoxon Rank Sum). Consistent with the survival data, treatment with combination therapy resulted in 2.0-3.5 log reduction in fungal burden of either organ vs. placebo and 1.0 log reduction vs. either drug alone (P & lt; 0.005). Similar results were obtained using mice infected with M. circinelloides. Conclusion L-AMB + ISAV demonstrate greater activity vs. monotherapy treatment in immunosuppressed mice infected with either of two common causes of mucormycosis. These studies warrant further investigation of LAmB + ISAV combination therapy as an optimal therapy of human mucormycosis. Disclosures Therese Kitt, MD, Astellas Pharma (Employee) Ashraf S. Ibrahim, PhD, Astellas Pharma (Research Grant or Support)
    Type of Medium: Online Resource
    ISSN: 2328-8957
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2020
    detail.hit.zdb_id: 2757767-3
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  • 13
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2019
    In:  Open Forum Infectious Diseases Vol. 6, No. Supplement_2 ( 2019-10-23), p. S632-S632
    In: Open Forum Infectious Diseases, Oxford University Press (OUP), Vol. 6, No. Supplement_2 ( 2019-10-23), p. S632-S632
    Abstract: Mucormycosis is a serious infection caused by fungi of the order Mucorales. Rhizopus delemar is the most common etiologic agent of mucormycosis. Pathogenesis studies of mucormycosis have been hampered by poor genetic trackability of the organism, owing to rare chromosomal integration events and multinucleated nature of the cells. The clustered regularly interspaced short palindromic repeat (CRISPR)-associated nuclease 9 (Cas9) system has been widely used in genetic manipulation through efficient homologous and non-homologous break points in a variety of organisms including R. delemar. However, plasmid-free CRISPR/Cas9 system has not been previously described in the fungus. Here, we introduce a rapid plasmid-free system for inducing orotidine 5’-phosphate decarboxylase (pyrF) gene mutation in R. delemar. Methods Protoplasts of R. delemar 99–880 strain were transformed with 20 nucleotide gRNA targeting the N-terminus of pyrF gene and the Cas9 enzyme. Screening for pyrF auxotrophy was carried out by plating transformed protoplasts on potato dextrose agar (PDA) plates containing 1 mg/mL 5-fluoroorotic acid (5-FOA) and 100 µg/mL uracil. Putative mutant strains were selected for uracil auxotrophy by plating simultaneously on media with or without uracil. pyrF disruption was verified by using PCR and qRT–PCR. Results Approximately100 transformants were generated through plating on 5-FOA plates. Only three transformants did not grow on minimal medium lacking uracil, indicating that they were true pyrF null mutants. PCR analysis showed that these three transformants have undergone nucleotide deletion events within the pyrF gene. The lack of pyrF gene expression was further verified by using qRT–PCR relative to wild-type R. delemar 99–880. Conclusion Similar to the plasmid-based genome manipulation strategy, the plasmid-free CRISPR/Cas9 system can induce gene editing in R. delemar. This rapid and simple approach adds an additional tool in our conquest to understand pathogenesis of mucormycosis. Disclosures All authors: No reported disclosures.
    Type of Medium: Online Resource
    ISSN: 2328-8957
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2019
    detail.hit.zdb_id: 2757767-3
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  • 14
    In: mBio, American Society for Microbiology, Vol. 14, No. 1 ( 2023-02-28)
    Abstract: Mucormycosis is an invasive fungal infection caused by certain members of the fungal order of Mucorales. The species most frequently identified as the etiological agents of mucormycosis belong to the genera Rhizopus , Lichtheimia , and Mucor . The frequency of systemic mucormycosis has been increasing, mainly because of increasing numbers of susceptible patients. Furthermore, Mucorales display intrinsic resistance to the majority of routinely used antifungal agents (e.g., echinocandins and short-tailed azoles), which limits the number of possible therapeutic options. All the above-mentioned issues urge the improvement of molecular identification methods and the discovery of new antifungal targets and strategies. Spore coat proteins (CotH) constitute a kinase family present in many pathogenic bacteria and fungi and participate in the spore formation in these organisms. Moreover, some of them can act as virulence factors being receptors of the human GRP78 protein during Rhizopus delemar -induced mucormycosis. We identified 17 cotH -like genes in the Mucor lusitanicus genome database. Successful disruption of five cotH genes in Mucor was performed using the CRISPR-Cas9 system. The CotH3 and CotH4 proteins play a role in adaptation to different temperatures as well as in developing the cell wall structure. We also show CotH4 protein is involved in spore wall formation by affecting the total chitin content and, thus, the composition of the spore wall. The role of CotH3 and CotH4 proteins in virulence was confirmed in two invertebrate models and a diabetic ketoacidosis (DKA) mouse model. IMPORTANCE Current treatment options for mucormycosis are inadequate, resulting in high mortality rates, especially among immunosuppressed patients. The development of novel therapies for mucormycosis has been hampered by lack of understanding of the pathogenetic mechanisms. The importance of the cell surface CotH proteins in the pathogenesis of Rhizopus -mediated mucormycosis has been recently described. However, the contribution of this family of proteins to the virulence of other mucoralean fungi and their functionality in vital processes remain undefined. Through the use of the CRISPR-Case9 gene disruption system, we demonstrate the importance of several of the CotH proteins to the virulence of Mucor lusitanicus by using three infection models. We also report on the importance of one of these proteins, CotH4, to spore wall formation by affecting chitin content. Therefore, our studies extend the importance of CotH proteins to Mucor and identify the mechanism by which one of the CotH proteins contributes to the development of a normal fungal cell wall, thereby indicating that this family of proteins can be targeted for future development of novel therapeutic strategies of mucormycosis.
    Type of Medium: Online Resource
    ISSN: 2150-7511
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2023
    detail.hit.zdb_id: 2557172-2
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  • 15
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2019-02-26)
    Abstract: MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles in plant development and abiotic stresses. To date, studies have mainly focused on the roles of individual miRNAs, however, a few have addressed the interactions among multiple miRNAs. In this study, we investigated the interplay and regulatory circuit between miR160 and miR165/166 and its effect on leaf development and drought tolerance in Arabidopsis using Short Tandem Target Mimic (STTM). By crossing STTM160 Arabidopsis with STTM165/166, we successfully generated a double mutant of miR160 and miR165/166. The double mutant plants exhibited a series of compromised phenotypes in leaf development and drought tolerance in comparison to phenotypic alterations in the single STTM lines. RNA-seq and qRT-PCR analyses suggested that the expression levels of auxin and ABA signaling genes in the STTM-directed double mutant were compromised compared to the two single mutants. Our results also suggested that miR160-directed regulation of auxin response factors ( ARFs) contribute to leaf development via auxin signaling genes, whereas miR165/166- mediated HD-ZIP IIIs regulation confers drought tolerance through ABA signaling. Our studies further indicated that ARFs and HD-ZIP IIIs may play opposite roles in the regulation of leaf development and drought tolerance that can be further applied to other crops for agronomic traits improvement.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2019
    detail.hit.zdb_id: 2615211-3
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  • 16
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2012
    In:  The Plant Cell Vol. 24, No. 2 ( 2012-02), p. 415-427
    In: The Plant Cell, Oxford University Press (OUP), Vol. 24, No. 2 ( 2012-02), p. 415-427
    Type of Medium: Online Resource
    ISSN: 1040-4651 , 1532-298X
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2012
    detail.hit.zdb_id: 623171-8
    detail.hit.zdb_id: 2004373-9
    SSG: 12
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  • 17
    In: Open Forum Infectious Diseases, Oxford University Press (OUP), Vol. 9, No. Supplement_2 ( 2022-12-15)
    Abstract: Invasive mucormycosis (IM) is associated with high mortality and morbidity. MAT2203 is an encochleated oral formulation of amphotericin B which has been shown to be safe and effective against murine aspergillosis and murine cryptococcal meningoencephalitis. We sought to compare the efficacy of MAT2203 to liposomal amphotericin B (LAMB) treatment in a neutropenic mouse model of IM. Methods ICR mice were immunosuppressed with cyclophosphamide and cortisone acetate on days -2, -3 and +8, relative to infection with intratracheally instilled Rhizopus delemar 99-880 or M. circinelloides f. jenssenii DI15-131. Treatment with placebo (diluent control), oral MAT2203 (5 to 45 mg/kg, given qd or bid for 7 days) or LAMB (10 mg/kg, iv, qd for 4 days), began 16 h post infection. Survival (n=10-20/group from 1/2 experiments) through Day +21 and tissue fungal burden of lungs or brain (n=10/group) euthanized on Day +4 post infection (conidial equivalents using qPCR) served as a primary and secondary endpoint, respectively. Results For Rhizopus delemar infection, doses of MAT2203 5,15 mg/kg qd or 7.5 mg/kg bid, significantly prolonged median survival time (MST) and enhanced overall survival vs. placebo-treated mice (MST of 9 Days and 0% survival for placebo-treated mice vs. 13 Days, and 20-40% for MAT2203 doses, P & lt; 0.05 by Log-Rank). Importantly, MAT2203 treatments were as effective as LAMB (MST of 16 days and overall survival of 45%). For mice infected with M. circinelloides, MAT2203 at 15 mg/kg, qd significantly prolonged MST and enhanced overall survival vs. placebo-treated mice (MST of 5 Days and 0% survival, for placebo-treated mice vs. 13.5 Days and 50% survival for MAT2203, P & lt; 0.05). In both infection models MAT2203 treatment of 15 mg/kg or LAMB resulted in significant ∼1.0-1.5 log reduction and ∼2.0-2.2 log reduction in lung and brain fungal burden vs. placebo, respectively (Wilcoxon Rank Sum). Conclusion MAT2203 demonstrated in vivo efficacy in treating R. delemar or M. circinelloides pulmonary infection in immunosuppressed mice, which was equivalent to the LAMB current standard of care. Continued investigation and development of MAT2203 as a novel, and oral formulation of amphotericin antifungal agent against mucormycosis is warranted. Disclosures Theresa Matkovits, PhD, Matinas BioPharma: Employee Jenel Cobb, PhD, Matinas BioPharma: Employee Raphael J. Mannino, PhD, Matinas BioPharma: Employee Ashraf S. Ibrahim, PhD, Matinas BioPharma: Advisor/Consultant|Matinas BioPharma: Grant/Research Support|SFunga: Grant/Research Support.
    Type of Medium: Online Resource
    ISSN: 2328-8957
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2022
    detail.hit.zdb_id: 2757767-3
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  • 18
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2019
    In:  Open Forum Infectious Diseases Vol. 6, No. Supplement_2 ( 2019-10-23), p. S325-S326
    In: Open Forum Infectious Diseases, Oxford University Press (OUP), Vol. 6, No. Supplement_2 ( 2019-10-23), p. S325-S326
    Abstract: Mucormycosis is a life-threatening infection that predominantly occurs in immunocompromised hosts. The antifungal APX001A (manogepix) inhibits Gwt1, an enzyme required for the conserved glycosylphosphatidyl inositol (GPI) post-translational modification in eukaryotes. We previously reported the activity of APX001 (fosmanogepix, the prodrug of APX001A) against Rhizopus delemar (minimum effective concentration [MEC] = 0.25 µg/mL). Here we assessed the activity against R. oryzae, which has an elevated MEC value. Methods R. oryzae 99–892 MIC and MEC values were 0.125 µg/mL and 4.0 µg/mL for isavuconazole (ISAV) and APX001A, respectively. ICR mice were immunosuppressed with cyclophosphamide (200 mg/kg) and cortisone acetate (500 mg/kg) on Days -2, +3, and +8 relative to intratracheal infection with 2.5 × 105 cells of R. oryzae 99–892. For survival studies, treatment with 104 mg/kg APX001 was compared with ISAV (110 mg/kg TID). Oral treatment started on Day +1 through Day +7, relative to infection for survival studies, and through Day +4 for tissue fungal burden studies (assessed by conidial equivalent [CE] using qPCR). Placebo mice received vehicle control. To extend the half-life of APX001, mice were administered 50 mg/kg of the cytochrome P450 inhibitor 1-aminobenzotriazole (ABT) 2 h prior to APX001 administration. Results APX001 and ISAV equally prolonged median survival time of mice (n = 20) vs. placebo (12 and 14 days for APX001 and ISAV, respectively, vs. 8 days for placebo). Furthermore, APX001 and ISAV treatment both resulted in 30% 21-day survival vs. 0% survival of placebo mice (P 〈 0.05 by log-rank test). Both drug treatments resulted in ~1.5 log10 reduction in lung and brain CE vs. placebo-treated mice (n = 10, P 〈 0.005 by Wilcoxon rank-sum test). Conclusion Despite a higher MEC value, APX001 showed significant efficacy against R. oryzae that was as protective as ISAV in immunosuppressed mice. Given the previously reported activity of APX001 against a strain of R. delemar with a lower MEC value,APX001 has now been shown to be efficacious against both species of Rhizopus, which together are responsible for ~60–70% of isolates causing lethal mucormycosis. Thus, continued investigation of APX001 against mucormycosis is warranted. Disclosures All authors: No reported disclosures.
    Type of Medium: Online Resource
    ISSN: 2328-8957
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2019
    detail.hit.zdb_id: 2757767-3
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  • 19
    In: Nature Microbiology, Springer Science and Business Media LLC, Vol. 6, No. 3 ( 2021-01-18), p. 313-326
    Type of Medium: Online Resource
    ISSN: 2058-5276
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2845610-5
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  • 20
    In: Current Biology, Elsevier BV, Vol. 32, No. 5 ( 2022-03), p. 1115-1130.e6
    Type of Medium: Online Resource
    ISSN: 0960-9822
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2022
    detail.hit.zdb_id: 2019214-9
    SSG: 12
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