scholarly journals TgPRELID, a Mitochondrial Protein Linked to Multidrug Resistance in the Parasite Toxoplasma gondii

mSphere ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Victoria Jeffers ◽  
Edwin T. Kamau ◽  
Ananth R. Srinivasan ◽  
Jonathan Harper ◽  
Preethi Sankaran ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Toxoplasma Gondii ◽  
Mitochondrial Protein ◽  
Parasitic Infection ◽  
Common Mechanism ◽  
Parasitic Diseases ◽  
Content Type ◽  
New Therapies ◽  
Resistant Mutants

ABSTRACT We report the discovery of TgPRELID, a previously uncharacterized mitochondrial protein linked to multidrug resistance in the parasite Toxoplasma gondii. Drug resistance remains a major problem in the battle against parasitic infection, and understanding how TgPRELID mutations augment resistance to multiple, distinct compounds will reveal needed insights into the development of new therapies for toxoplasmosis and other related parasitic diseases. New drugs to control infection with the protozoan parasite Toxoplasma gondii are needed as current treatments exert toxic side effects on patients. Approaches to develop novel compounds for drug development include screening of compound libraries and targeted inhibition of essential cellular pathways. We identified two distinct compounds that display inhibitory activity against the parasite’s replicative stage: F3215-0002, which we previously identified during a compound library screen, and I-BET151, an inhibitor of bromodomains, the “reader” module of acetylated lysines. In independent studies, we sought to determine the targets of these two compounds using forward genetics, generating resistant mutants and identifying the determinants of resistance with comparative genome sequencing. Despite the dissimilarity of the two compounds, we recovered resistant mutants with nonsynonymous mutations in the same domain of the same gene, TGGT1_254250, which we found encodes a protein that localizes to the parasite mitochondrion (designated TgPRELID after the name of said domain). We found that mutants selected with one compound were cross resistant to the other compound, suggesting a common mechanism of resistance. To further support our hypothesis that TgPRELID mutations facilitate resistance to both I-BET151 and F3215-0002, CRISPR (clustered regularly interspaced short palindromic repeat)/CAS9-mediated mutation of TgPRELID directly led to increased F3215-0002 resistance. Finally, all resistance mutations clustered in the same subdomain of TgPRELID. These findings suggest that TgPRELID may encode a multidrug resistance factor or that I-BET151 and F3215-0002 have the same target(s) despite their distinct chemical structures. IMPORTANCE We report the discovery of TgPRELID, a previously uncharacterized mitochondrial protein linked to multidrug resistance in the parasite Toxoplasma gondii. Drug resistance remains a major problem in the battle against parasitic infection, and understanding how TgPRELID mutations augment resistance to multiple, distinct compounds will reveal needed insights into the development of new therapies for toxoplasmosis and other related parasitic diseases.

scholarly journals Dysfunction of Prohibitin 2 Results in Reduced Susceptibility to Multiple Antifungal Drugs via Activation of the Oxidative Stress-Responsive Transcription Factor Pap1 in Fission Yeast

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Qiannan Liu ◽  
Fan Yao ◽  
Guanglie Jiang ◽  
Min Xu ◽  
Si Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Drug Resistance ◽  
Transcription Factor ◽  
Fission Yeast ◽  
Mitochondrial Protein ◽  
Antifungal Drugs ◽  
Antifungal Drug ◽  
Gene Encoding ◽  
Content Type ◽  
Antifungal Drug Resistance

ABSTRACT The fight against resistance to antifungal drugs requires a better understanding of the underlying cellular mechanisms. In order to gain insight into the mechanisms leading to antifungal drug resistance, we performed a genetic screen on a model organism, Schizosaccharomyces pombe, to identify genes whose overexpression caused resistance to antifungal drugs, including clotrimazole and terbinafine. We identified the phb2+ gene, encoding a highly conserved mitochondrial protein, prohibitin (Phb2), as a novel determinant of reduced susceptibility to multiple antifungal drugs. Unexpectedly, deletion of the phb2+ gene also exhibited antifungal drug resistance. Overexpression of the phb2+ gene failed to cause drug resistance when the pap1+ gene, encoding an oxidative stress-responsive transcription factor, was deleted. Furthermore, pap1+ mRNA expression was significantly increased when the phb2+ gene was overexpressed or deleted. Importantly, either overexpression or deletion of the phb2+ gene stimulated the synthesis of NO and reactive oxygen species (ROS), as measured by the cell-permeant fluorescent NO probe DAF-FM DA (4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate) and the ROS probe DCFH-DA (2′,7′-dichlorodihydrofluorescein diacetate), respectively. Taken together, these results suggest that Phb2 dysfunction results in reduced susceptibility to multiple antifungal drugs by increasing NO and ROS synthesis due to dysfunctional mitochondria, thereby activating the transcription factor Pap1 in fission yeast.

scholarly journals Global Screening of Genomic and Transcriptomic Factors Associated with Phenotype Differences between Multidrug-Resistant and -Susceptible Candida haemulonii Strains

mSystems ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Hao Zhang ◽  
Yifei Niu ◽  
Jingwen Tan ◽  
Weixia Liu ◽  
Ming-an Sun ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Wall ◽  
Multidrug Resistance ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Cell Wall Integrity ◽  
Close Relative ◽  
Content Type ◽  
Candida Haemulonii ◽  
Resistant Strains

ABSTRACT Candida haemulonii, a close relative of Candida auris, is an emerging pathogen which frequently shows multidrug resistance especially to triazoles, the most used antifungal drugs. The mechanisms of drug resistance in C. haemulonii, however, are largely unknown. Here, we sequenced and annotated the genomes of two reference strains from the C. haemulonii complex, compared the phenotypes, genomes, and transcriptomes of a triazole-susceptible and two triazole-resistant C. haemulonii strains, and identified triazole susceptibility, morphology, fitness, and the major genetic and gene expression differences between the strains. A multidrug efflux gene, CDR1, was recurrently found to be upregulated for expression in triazole-resistant strains. Blocking the activity of Cdr1 increased the susceptibility to triazoles strikingly. Comparative transcriptome analysis also demonstrated impaired cell wall integrity, filamentous growth, and iron homeostasis in triazole-resistant strains. Finally, we also identified a zinc-binding MHR family transcription regulator gene that mutated in triazole-resistant strains spontaneously, contributing to the changes of morphology and, possibly, cell wall integrity between the strains. The study provided important clues for future studies exploring the mechanisms of multidrug resistance and related phenotypic differences of C. haemulonii strains. IMPORTANCE A comprehensive, multi-omic survey was performed to disclose the genetic backgrounds and differences between multidrug-resistant and -susceptible C. haemulonii strains. Genes were identified with mutations or significant expression differences in multidrug-resistant compared to multidrug-susceptible strains, which were mainly involved in multidrug resistance, stress fitness, and morphology. The Cdr1-encoding gene, C. haemulonii 2486 (CH_2486), was expressed at a significantly increased level in multidrug-resistant strains. Functional inhibition experiments further implicated potential roles of CH_2486 in drug resistance. A gene spontaneously mutated in resistant strains, CH_4347, was experimentally validated to influence the morphology of spores, possibly by controlling cell wall integrity.

scholarly journals Role ofPfmdr1inIn VitroPlasmodium falciparum Susceptibility to Chloroquine, Quinine, Monodesethylamodiaquine, Mefloquine, Lumefantrine, and Dihydroartemisinin

2014 ◽  
Vol 58 (12) ◽  
pp. 7032-7040 ◽  
Author(s):  
Nathalie Wurtz ◽  
Bécaye Fall ◽  
Aurélie Pascual ◽  
Mansour Fall ◽  
Eric Baret ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Multidrug Resistance ◽  
Antimalarial Drug ◽  
Antimalarial Drugs ◽  
Wild Type ◽  
Antimalarial Drug Resistance ◽  
Content Type ◽  
Increased Susceptibility

ABSTRACTThe involvement ofPfmdr1(Plasmodium falciparummultidrug resistance 1) polymorphisms in antimalarial drug resistance is still debated. Here, we evaluate the association between polymorphisms inPfmdr1(N86Y, Y184F, S1034C, N1042D, and D1246Y) andPfcrt(K76T) andin vitroresponses to chloroquine (CQ), mefloquine (MQ), lumefantrine (LMF), quinine (QN), monodesethylamodiaquine (MDAQ), and dihydroartemisinin (DHA) in 174Plasmodium falciparumisolates from Dakar, Senegal. ThePfmdr186Y mutation was identified in 14.9% of the samples, and the 184F mutation was identified in 71.8% of the isolates. No 1034C, 1042N, or 1246Y mutations were detected. ThePfmdr186Y mutation was significantly associated with increased susceptibility to MDAQ (P= 0.0023), LMF (P= 0.0001), DHA (P= 0.0387), and MQ (P= 0.00002). The N86Y mutation was not associated with CQ (P= 0.214) or QN (P= 0.287) responses. ThePfmdr1184F mutation was not associated with various susceptibility responses to the 6 antimalarial drugs (P= 0.168 for CQ, 0.778 for MDAQ, 0.324 for LMF, 0.961 for DHA, 0.084 for QN, and 0.298 for MQ). ThePfmdr186Y-Y184 haplotype was significantly associated with increased susceptibility to MDAQ (P= 0.0136), LMF (P= 0.0019), and MQ (P= 0.0001). The additionalPfmdr186Y mutation increased significantly thein vitrosusceptibility to MDAQ (P< 0.0001), LMF (P< 0.0001), MQ (P< 0.0001), and QN (P= 0.0026) in wild-typePfcrtK76 parasites. The additionalPfmdr186Y mutation significantly increased thein vitrosusceptibility to CQ (P= 0.0179) inPfcrt76T CQ-resistant parasites.

scholarly journals Pantothenic Acid Biosynthesis in the Parasite Toxoplasma gondii: a Target for Chemotherapy

2014 ◽  
Vol 58 (11) ◽  
pp. 6345-6353 ◽  
Author(s):  
Sarmad N. Mageed ◽  
Fraser Cunningham ◽  
Alvin Wei Hung ◽  
Hernani Leonardo Silvestre ◽  
Shijun Wen ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Drug Target ◽  
Parasitic Infection ◽  
Pantothenic Acid ◽  
Acid Biosynthesis ◽  
Content Type ◽  
Pantothenate Synthetase ◽  
Genes Encoding ◽  
Range Of Values ◽  
Important Parasite

ABSTRACTToxoplasma gondiiis a major food pathogen and neglected parasitic infection that causes eye disease, birth defects, and fetal abortion and plays a role as an opportunistic infection in AIDS. In this study, we investigated pantothenic acid (vitamin B5) biosynthesis inT. gondii. Genes encoding the full repertoire of enzymes for pantothenate synthesis and subsequent metabolism to coenzyme A were identified and are expressed inT. gondii. A panel of inhibitors developed to targetMycobacterium tuberculosispantothenate synthetase were tested and found to exhibit a range of values for inhibition ofT. gondiigrowth. Two inhibitors exhibited lower effective concentrations than the currently used toxoplasmosis drug pyrimethamine. The inhibition was specific for the pantothenate pathway, as the effect of the pantothenate synthetase inhibitors was abrogated by supplementation with pantothenate. Hence,T. gondiiencodes and expresses the enzymes for pantothenate synthesis, and this pathway is essential for parasite growth. These promising findings increase our understanding of growth and metabolism in this important parasite and highlight pantothenate synthetase as a new drug target.

scholarly journals Mitochondrial dysfunctions trigger the calcium signaling-dependent fungal multidrug resistance

2019 ◽  
Vol 117 (3) ◽  
pp. 1711-1721 ◽  
Author(s):  
Yeqi Li ◽  
Yuanwei Zhang ◽  
Chi Zhang ◽  
Hongchen Wang ◽  
Xiaolei Wei ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Mitochondrial Dysfunction ◽  
Calcium Signaling ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Drug Binding ◽  
Fitness Cost ◽  
Drug Resistant ◽  
Resistant Mutants

Drug resistance in fungal pathogens has risen steadily over the past decades due to long-term azole therapy or triazole usage in agriculture. Modification of the drug target protein to prevent drug binding is a major recognized route to induce drug resistance. However, mechanisms for nondrug target-induced resistance remain only loosely defined. Here, we explore the molecular mechanisms of multidrug resistance resulted from an efficient adaptation strategy for survival in drug environments in the human pathogen Aspergillus fumigatus. We show that mutants conferring multidrug resistance are linked with mitochondrial dysfunction induced by defects in heme A biosynthesis. Comparison of the gene expression profiles between the drug-resistant mutants and the parental wild-type strain shows that multidrug-resistant transporters, chitin synthases, and calcium-signaling-related genes are significantly up-regulated, while scavenging mitochondrial reactive oxygen species (ROS)-related genes are significantly down-regulated. The up-regulated-expression genes share consensus calcium-dependent serine threonine phosphatase-dependent response elements (the binding sites of calcium-signaling transcription factor CrzA). Accordingly, drug-resistant mutants show enhanced cytosolic Ca2+ transients and persistent nuclear localization of CrzA. In comparison, calcium chelators significantly restore drug susceptibility and increase azole efficacy either in laboratory-derived or in clinic-isolated A. fumigatus strains. Thus, the mitochondrial dysfunction as a fitness cost can trigger calcium signaling and, therefore, globally up-regulate a series of embedding calcineurin-dependent–response-element genes, leading to antifungal resistance. These findings illuminate how fitness cost affects drug resistance and suggest that disruption of calcium signaling might be a promising therapeutic strategy to fight against nondrug target-induced drug resistance.

scholarly journals Candida glabrata Drug:H+Antiporter CgQdr2 Confers Imidazole Drug Resistance, Being Activated by Transcription Factor CgPdr1

2013 ◽  
Vol 57 (7) ◽  
pp. 3159-3167 ◽  
Author(s):  
Catarina Costa ◽  
Carla Pires ◽  
Tânia R. Cabrito ◽  
Adeline Renaudin ◽  
Michiyo Ohno ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Transcription Factor ◽  
Multidrug Resistance ◽  
Candida Glabrata ◽  
Antifungal Drugs ◽  
Antifungal Drug ◽  
Major Facilitator Superfamily ◽  
Pathogenic Yeast ◽  
Content Type ◽  
Antifungal Drug Resistance

ABSTRACTThe widespread emergence of antifungal drug resistance poses a severe clinical problem. Though predicted to play a role in this phenomenon, the drug:H+antiporters (DHA) of the major facilitator superfamily have largely escaped characterization in pathogenic yeasts. This work describes the first DHA from the pathogenic yeastCandida glabratareported to be involved in antifungal drug resistance, theC. glabrata QDR2(CgQDR2) gene (ORFCAGL0G08624g). The expression ofCgQDR2inC. glabratawas found to confer resistance to the antifungal drugs miconazole, tioconazole, clotrimazole, and ketoconazole. By use of a green fluorescent protein (GFP) fusion, the CgQdr2 protein was found to be targeted to the plasma membrane inC. glabrata. In agreement with these observations,CgQDR2expression was found to decrease the intracellular accumulation of radiolabeled clotrimazole inC. glabrataand to play a role in the extrusion of this antifungal from preloaded cells. Interestingly, the functional heterologous expression ofCgQDR2in the model yeastSaccharomyces cerevisiaefurther confirmed the role of this gene as a multidrug resistance determinant: its expression was able to complement the susceptibility phenotype exhibited by itsS. cerevisiaehomologue,QDR2, in the presence of imidazoles and of the antimalarial and antiarrhythmic drug quinidine. In contrast to the findings reported for Qdr2, CgQdr2 expression does not contribute to the ability of yeast to grow under K+-limiting conditions. Interestingly,CgQDR2transcript levels were seen to be upregulated inC. glabratacells challenged with clotrimazole or quinidine. This upregulation was found to depend directly on the transcription factor CgPdr1, the major regulator of multidrug resistance in this pathogenic yeast, which has also been found to be a determinant of quinidine and clotrimazole resistance inC. glabrata.

scholarly journals Azole Drug Import into the Pathogenic Fungus Aspergillus fumigatus

2015 ◽  
Vol 59 (6) ◽  
pp. 3390-3398 ◽  
Author(s):  
Brooke D. Esquivel ◽  
Adam R. Smith ◽  
Martin Zavrel ◽  
Theodore C. White
Keyword(s):  
Drug Resistance ◽  
Aspergillus Fumigatus ◽  
Fungal Infections ◽  
Pathogenic Fungus ◽  
Diffusion Mechanism ◽  
Ergosterol Biosynthesis ◽  
Common Mechanism ◽  
Facilitated Diffusion ◽  
Biosynthesis Pathway ◽  
Content Type

ABSTRACTThe fungal pathogenAspergillus fumigatuscauses serious illness and often death when it invades tissues, especially in immunocompromised individuals. The azole class of drugs is the most commonly prescribed treatment for many fungal infections and acts on the ergosterol biosynthesis pathway. One common mechanism of acquired azole drug resistance in fungi is the prevention of drug accumulation to toxic levels in the cell. While drug efflux is a well-known resistance strategy, reduced azole import would be another strategy to maintain low intracellular azole levels. Recently, azole uptake inCandida albicansand other yeasts was analyzed using [3H]fluconazole. Defective drug import was suggested to be a potential mechanism of drug resistance in several pathogenic fungi, includingCryptococcus neoformans,Candida krusei, andSaccharomyces cerevisiae. We have adapted and developed an assay to measure azole accumulation inA. fumigatususing radioactively labeled azole drugs, based on previous work done withC. albicans. We used this assay to study the differences in azole uptake inA. fumigatusisolates under a variety of drug treatment conditions, with different morphologies and with a select mutant strain with deficiencies in the sterol uptake and biosynthesis pathway. We conclude that azole drugs are specifically selected and imported into the fungal cell by a pH- and ATP-independent facilitated diffusion mechanism, not by passive diffusion. This method of drug transport is likely to be conserved across most fungal species.

scholarly journals Selective Conditions for a Multidrug Resistance Plasmid Depend on the Sociality of Antibiotic Resistance

2016 ◽  
Vol 60 (4) ◽  
pp. 2524-2527 ◽  
Author(s):  
Michael J. Bottery ◽  
A. Jamie Wood ◽  
Michael A. Brockhurst
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Mechanisms Of Resistance ◽  
Content Type ◽  
Drug Concentrations ◽  
Selection For ◽  
Free Strain

ABSTRACTMultidrug resistance (MDR) plasmids frequently carry antibiotic resistance genes conferring qualitatively different mechanisms of resistance. We show here that the antibiotic concentrations selecting for the RK2 plasmid inEscherichia colidepend upon the sociality of the drug resistance: the selection for selfish drug resistance (efflux pump) occurred at very low drug concentrations, just 1.3% of the MIC of the plasmid-free antibiotic-sensitive strain, whereas selection for cooperative drug resistance (modifying enzyme) occurred at drug concentrations exceeding the MIC of the plasmid-free strain.

scholarly journals Influence of Antituberculosis Drug Resistance and Mycobacterium tuberculosis Lineage on Outcome in HIV-Associated Tuberculous Meningitis

2012 ◽  
Vol 56 (6) ◽  
pp. 3074-3079 ◽  
Author(s):  
Dau Quang Tho ◽  
M. Estée Török ◽  
Nguyen Thi Bich Yen ◽  
Nguyen Duc Bang ◽  
Nguyen Thi Ngoc Lan ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Multidrug Resistance ◽  
High Mortality ◽  
Tuberculous Meningitis ◽  
Hazard Ratio ◽  
Antituberculosis Drug ◽  
Isoniazid Resistance ◽  
Content Type ◽  
Kaplan Meier

ABSTRACTHIV-associated tuberculous meningitis (TBM) has high mortality. Aside from the devastating impact of multidrug resistance (MDR) on survival, little is understood about the influence of other bacterial factors on outcome. This study examined the influence ofMycobacterium tuberculosisdrug resistance, bacterial lineage, and host vaccination status on outcome in patients with HIV-associated TBM.Mycobacterium tuberculosisisolates from the cerebrospinal fluid of 186 patients enrolled in two studies of HIV-associated TBM in Ho Chi Minh City, Vietnam, were tested for resistance to first-line antituberculosis drugs. Lineage genotyping was available for 122 patients. The influence of antituberculosis drug resistance andM. tuberculosislineage on 9-month mortality was analyzed using Kaplan-Meier survival analysis and Cox multiple regression models. Isoniazid (INH) resistance without rifampin resistance was associated with increased mortality (adjusted hazard ratio [HR], 1.78, 95% confidence interval [CI], 1.18 to 2.66;P= 0.005), and multidrug resistance was uniformly fatal (n= 8/8; adjusted HR, 5.21, 95% CI, 2.38 to 11.42;P< 0.0001). The hazard ratio for INH-resistant cases was greatest during the continuation phase of treatment (after 3 months; HR, 5.05 [95% CI, 2.23 to 11.44];P= 0.0001). Among drug-susceptible cases, patients infected with the “modern” Beijing lineage strains had lower mortality than patients infected with the “ancient” Indo-Oceanic lineage (HR, 0.29 [95% CI, 0.14 to 0.61];P= 0.001). Isoniazid resistance, multidrug resistance, andM. tuberculosislineage are important determinants of mortality in patients with HIV-associated TBM. Interventions which target these factors may help reduce the unacceptably high mortality in patients with TBM.

scholarly journals Toxoplasma gondii Induces B7-2 Expression through Activation of JNK Signal Transduction

2011 ◽  
Vol 79 (11) ◽  
pp. 4401-4412 ◽  
Author(s):  
Pedro Morgado ◽  
Yi-Ching Ong ◽  
John C. Boothroyd ◽  
Melissa B. Lodoen
Keyword(s):  
T Cell ◽  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Transcriptional Analysis ◽  
Common Mechanism ◽  
Mouse Bone Marrow ◽  
Dependent Manner ◽  
Content Type ◽  
Naïve T Cell ◽  
Naive T Cell

ABSTRACTToxoplasma gondiiis a globally distributed parasite pathogen that infects virtually all warm-blooded animals. A hallmark of immunity to acute infection is the production of gamma interferon (IFN-γ) and interleukin-12 (IL-12), followed by a protective T cell response that is critical for parasite control. Naïve T cell activation requires both T-cell receptor (TCR) stimulation and the engagement of costimulatory receptors. Because of their important function in activating T cells, the expression of costimulatory ligands is believed to be under tight control. The molecular mechanisms governing their induction during microbial stimulation, however, are not well understood. We found that all three strains ofT. gondii(types I, II, and III) upregulated the expression of B7-2, but not B7-1, on the surface of mouse bone marrow-derived macrophages. Additionally, intraperitoneal infection of mice with green fluorescent protein (GFP)-expressing parasites resulted in enhanced B7-2 levels specifically on infected, GFP+CD11b+cells. B7-2 induction occurred at the transcript level, required active parasite invasion, and was not dependent on MyD88 or TRIF. Functional assays demonstrated thatT. gondii-infected macrophages stimulated naïve T cell proliferation in a B7-2-dependent manner. Genome-wide transcriptional analysis comparing infected and uninfected macrophages revealed the activation of mitogen-activated protein kinase (MAPK) signaling in infected cells. Using specific inhibitors against MAPKs, we determined that parasite-induced B7-2 is dependent on Jun N-terminal protein kinase (JNK) but not extracellular signal-regulated kinase (ERK) or p38 signaling. We also observed thatT. gondii-induced B7-2 expression on human peripheral blood monocytes is dependent on JNK signaling, indicating that a common mechanism of B7-2 regulation byT. gondiimay exist in both humans and mice.

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