scholarly journals Production of the Invasive Aspergillosis Biomarker Bis(methylthio)gliotoxin Within the Genus Aspergillus: In Vitro and in Vivo Metabolite Quantification and Genomic Analysis

2018 ◽  
Vol 9 ◽  
Author(s):  
Matxalen Vidal-García ◽  
Sergio Redrado ◽  
M. Pilar Domingo ◽  
Patricia Marquina ◽  
Cristina Colmenarejo ◽  
...  
Keyword(s):  
Invasive Aspergillosis ◽  
Genomic Analysis ◽  
Metabolite Quantification

scholarly journals 1346. The Tetrazole VT-1598 Is Efficacious in a Murine Model of Invasive Aspergillosis with a PK/PD Expected of a Mold-Active CYP51 Inhibitor

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S411-S412
Author(s):  
Edward P Garvey ◽  
Andrew Sharp ◽  
Peter Warn ◽  
Christopher M Yates ◽  
Robert J Schotzinger
Keyword(s):  
Antifungal Activity ◽  
Invasive Aspergillosis ◽  
Murine Model ◽  
Pathogenic Fungi ◽  
Rational Drug Design ◽  
Fungal Burden ◽  
Delayed Treatment ◽  
Rational Drug

Abstract Background VT-1598 is a novel fungal CYP51 inhibitor with potent in vitro activity against yeast, mold, and endemic pathogenic fungi (Wiederhold, JAC, 2017). Its tetrazole-based rational drug design imparts much greater selectivity vs. human CYPs (Yates, BMCL, 2017), which could reduce human CYP-related side effects and DDIs. We report here VT-1598’s in vivo activity in an invasive aspergillosis (IA) model. Methods MIC was determined as outlined in CLSI M38-A2. Plasma PK was measured after 4 days of oral doses in neutropenic ICR mice without fungal inoculation. In vivo antifungal activity was determined in a tail-vein IA model in neutropenic mice inoculated with A. fumigatus (AF) ATCC 204305 (N = 10 per dose). Two separate studies were conducted, with oral VT-1598 treatment starting either 48 hours prior (prophylaxis) or 5 hours postinoculation (delayed), with 4 days of postinoculation dosing, and kidney fungal burden measured 1 day post last dose by both CFU and qPCR. Drug control was 10 mg/kg AmBisome i.v. Results The MIC for VT-1598 against AF 204305 was 0.25 μg/mL. The plasma PK of VT-1598 was linearly proportional between the 5 and 40 mg/kg once-daily doses, with AUCs of 155 and 1,033 μg h/mL for the two doses, respectively. VT-1598 was similarly effective in reducing fungal burden when given in delayed treatment compared with prophylaxis, and both studies demonstrated a full dose–response (i.e., no to full reduction of fungal burden). When comparing fungal burdens of each dose group to the fungal burden at the start of treatment, the dose of VT-1598 to achieve fungal stasis ranged from 20.5 to 25.9 mg/kg and to achieve a 1-log10 fungal kill ranged from 30.9 to 50.5 mg/kg. Using the previously measured mouse plasma binding (>99.9%), the free AUC /MIC values for stasis and 1-log10 kill ranged from 2.1–2.7 and 3.2–5.2, respectively. These values are within the range of 1–11 that have been reported for posaconazole and isavuconazole (Lepak, AAC, 2013). Conclusion VT-1598 had potent antifungal activity in a murine model of IA. The PK/PD relationship was the same as clinically used mold-active CYP51 agents, suggesting that it could have similar clinical efficacy. If correct, the tetrazole-based greater selectivity may significantly differentiate VT-1598 from current IA therapies. Disclosures E. P. Garvey, Viamet Pharmaceuticals, Inc.: Employee, Salary. A. Sharp, Evotec (UK) Ltd.: Employee, Salary. P. Warn, Evotec (UK) Ltd.: Employee, Salary. C. M. Yates, Viamet Pharmaceuticals, Inc.: Employee, Salary. R. J. Schotzinger, Viamet Pharmaceuticals, Inc.: Board Member and Employee, Salary.

scholarly journals Efficient Clearance of Aspergillus fumigatus in Murine Lungs by an Ultrashort Antimicrobial Lipopeptide, Palmitoyl-Lys-Ala-dAla-Lys

2008 ◽  
Vol 52 (9) ◽  
pp. 3118-3126 ◽  
Author(s):  
Alexandra Vallon-Eberhard ◽  
Arik Makovitzki ◽  
Anne Beauvais ◽  
Jean-Paul Latgé ◽  
Steffen Jung ◽  
...  
Keyword(s):  
Invasive Aspergillosis ◽  
Aspergillus Fumigatus ◽  
Microscopic Analysis ◽  
Current Standard ◽  
New Family ◽  
Therapeutic Properties ◽  
Survival Assay ◽  
Opportunistic Fungal Pathogen

ABSTRACT Aspergillus fumigatus is an opportunistic fungal pathogen responsible for invasive aspergillosis in immunocompromised individuals. The inefficiency of antifungal agents and high mortality rate resulting from invasive aspergillosis remain major clinical concerns. Recently, we reported on a new family of ultrashort cationic lipopeptides active in vitro against fungi. Mode of action studies supported a membranolytic or a detergent-like effect. Here, we screened several lipopeptides in vitro for their anti-A. fumigatus activity. To investigate the therapeutic properties of the selected peptides in vivo, we challenged immunosuppressed C57BL/6 wild-type mice intranasally with DsRed-labeled A. fumigatus conidia and subsequently treated the animals locally with the lipopeptides. Confocal microscopic analysis revealed the degradation of DsRed-labeled hyphal forms and residual conidia in the lungs of the mice. The most efficient peptide was tested further using a survival assay and was found to significantly prolong the life of the treated animals, whereas no mice survived with the current standard antifungal treatment with amphotericin B. Moreover, as opposed to the drug-treated lungs, the peptide-treated lungs did not display any toxicity of the peptide. Our results highlight the potential of this family of lipopeptides for the treatment of pulmonary invasive aspergillosis.

scholarly journals Genomic Analysis Identifies NovelPseudomonas aeruginosaResistance Genes under Selection during Inhaled Aztreonam TherapyIn Vivo

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Kathryn McLean ◽  
Duankun Lee ◽  
Elizabeth A. Holmes ◽  
Kelsi Penewit ◽  
Adam Waalkes ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Positive Selection ◽  
Single Gene ◽  
Genomic Analysis ◽  
Maximal Activity ◽  
Content Type ◽  
Cystic Fibrosis Airway ◽  
Bacterial Fitness

ABSTRACTInhaled aztreonam is increasingly used for chronicPseudomonas aeruginosasuppression in patients with cystic fibrosis (CF), but the potential for that organism to evolve aztreonam resistance remains incompletely explored. Here, we performed genomic analysis of clonally related pre- and posttreatment CF clinical isolate pairs to identify genes that are under positive selection during aztreonam therapyin vivo. We identified 16 frequently mutated genes associated with aztreonam resistance, the most prevalent beingftsIandampC, and 13 of which increased aztreonam resistance when introduced as single gene transposon mutants. Several previously implicated aztreonam resistance genes were found to be under positive selection in clinical isolates even in the absence of inhaled aztreonam exposure, indicating that other selective pressures in the cystic fibrosis airway can promote aztreonam resistance. Given its potential to confer plasmid-mediated resistance, we further characterized mutantampCalleles and performed artificial evolution ofampCfor maximal activity against aztreonam. We found that naturally occurringampCmutants conferred variably increased resistance to aztreonam (2- to 64-fold) and other β-lactam agents but that its maximal evolutionary capacity for hydrolyzing aztreonam was considerably higher (512- to 1,024-fold increases) and was achieved while maintaining or increasing resistance to other drugs. These studies implicate novel chromosomal aztreonam resistance determinants while highlighting that different mutations are favored during selectionin vivoandin vitro, show thatampChas a high maximal potential to hydrolyze aztreonam, and provide an approach to disambiguate mutations promoting specific resistance phenotypes from those more generally increasing bacterial fitnessin vivo.

scholarly journals 260. Detection of Aspergillus fumigatus Infection in Mice with 2-Deoxy-2-[18F]fluorosorbitol

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S144-S145
Author(s):  
Yohan Yu ◽  
Seung ji Kang ◽  
Dong-Yeon Kim ◽  
Ayoung Pyo ◽  
Sehyeon Ji ◽  
...  
Keyword(s):  
Invasive Aspergillosis ◽  
Pet Imaging ◽  
Ph Value ◽  
Diagnostic Methods ◽  
Bacterial Strains ◽  
Brain Infection ◽  
Uptake Assay ◽  
Uptake Test

Abstract Background Invasive aspergillosis is a major cause of infectious morbidity and mortality in immunocompromised patients.However, definitive diagnosis of invasive Aspergillus infection is still difficult due to the lack of a rapid, sensitive and specific diagnostic methods. In this studies, we investigated 2-deoxy-2-[18F]fluorosorbitol ([18F]FDS) which has been reported to be accumulated in Gram-negative bacteria but not in Gram-positive bacteria or healthy mammalian or cancer cells, for the imaging detection of Aspergullus fumigatus infections with PET in vivo. Methods [18F]FDS was synthesized by reduction of 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) using NaBH4. When the reaction was complete, the mixture was adjusted to a pH value to 6.5–7.5. Subsequently, the solution was filtered directly into a sterile product vial through a Sep-Pak Alumina N cartridge with a sterile filter. The probe uptake assay was performed by incubating bacterial cell and fungi with [18F]FDS (20 µCi) at 37°C for 2 h. Female BALB/c were immunosuppressed with cyclophosphamide and cortisone acetate prior to A. fumigatus intranasal, intramuscular, brain infection. The mircoPET images were obtained at 2 h after i.v. injection of [18F]FDS in infected mice. Results In vitro uptake test revealed significantly higher accumulation of [18F]FDS at 2 hin A. fumigatus, C. albicans and R. oryzae rather than with bacterial strains (Figure 1). PET imaging of BALB/c mice with pulmonary A. fumigatus infections showed obvious accumulation of [18F]FDS in the infected lungs compared with control (Figure 2). [18F]FDS PET imaging also detected A. fumigatus muscle and brain infection in mice. In infected shoulder muscle of mice, [18F]FDS PET imaging showed high legion-to-background ratio at 2 h. (4.05 ± 1.59, Figure 3). Conclusion [18F]FDS PET study demonstrated stable uptake in infected tissue with A. fumigatus and rapid clearance from the blood and other organs. [18F]FDS could be a useful imaging probe visualizing the invasive aspergillosis in vivo. Disclosures All authors: No reported disclosures.

Extended-spectrum resistance to β-lactams/β-lactamase inhibitors (ESRI) evolved from low-level resistant Escherichia coli

2019 ◽  
Author(s):  
Ángel Rodríguez-Villodres ◽  
María Luisa Gil-Marqués ◽  
Rocío Álvarez-Marín ◽  
Rémy A Bonnin ◽  
María Eugenia Pachón-Ibáñez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clavulanic Acid ◽  
Genomic Analysis ◽  
E Coli ◽  
Extended Spectrum ◽  
Copy Numbers ◽  
Resistance Patterns ◽  
Amoxicillin Clavulanic Acid

Abstract Objectives Escherichia coli is characterized by three resistance patterns to β-lactams/β-lactamase inhibitors (BLs/BLIs): (i) resistance to ampicillin/sulbactam and susceptibility to amoxicillin/clavulanic acid and piperacillin/tazobactam (RSS); (ii) resistance to ampicillin/sulbactam and amoxicillin/clavulanic acid, and susceptibility to piperacillin/tazobactam (RRS); and (iii) resistance to ampicillin/sulbactam, amoxicillin/clavulanic acid and piperacillin/tazobactam (RRR). These resistance patterns are acquired consecutively, indicating a potential risk of developing resistance to piperacillin/tazobactam, but the precise mechanism of this process is not completely understood. Methods Clinical isolates incrementally pressured by piperacillin/tazobactam selection in vitro and in vivo were used. We determined the MIC of piperacillin/tazobactam in the presence and absence of piperacillin/tazobactam pressure. We deciphered the role of the blaTEM genes in the new concept of extended-spectrum resistance to BLs/BLIs (ESRI) using genomic analysis. The activity of β-lactamase was quantified in these isolates. Results We show that piperacillin/tazobactam resistance is induced in E. coli carrying blaTEM genes. This resistance is due to the increase in copy numbers and transcription levels of the blaTEM gene, thus increasing β-lactamase activity and consequently increasing piperacillin/tazobactam MICs. Genome sequencing of two blaTEM-carrying representative isolates showed that piperacillin/tazobactam treatment produced two types of duplications of blaTEM (8 and 60 copies, respectively). In the clinical setting, piperacillin/tazobactam treatment of patients infected by E. coli carrying blaTEM is associated with a risk of therapeutic failure. Conclusions This study describes for the first time the ESRI in E. coli. This new concept is very important in the understanding of the mechanism involved in the acquisition of resistance to BLs/BLIs.

scholarly journals Aspergillus fumigatus inhibits angiogenesis through the production of gliotoxin and other secondary metabolites

Blood ◽  
2009 ◽  
Vol 114 (26) ◽  
pp. 5393-5399 ◽  
Author(s):  
Ronen Ben-Ami ◽  
Russell E. Lewis ◽  
Konstantinos Leventakos ◽  
Dimitrios P. Kontoyiannis
Keyword(s):  
Invasive Aspergillosis ◽  
Aspergillus Fumigatus ◽  
Capillary Tube ◽  
Umbilical Vein ◽  
Tube Formation ◽  
Dependent Manner ◽  
Antiangiogenic Effect ◽  
Umbilical Vein Endothelial Cells

AbstractIn susceptible hosts, angioinvasion by Aspergillus fumigatus triggers thrombosis, hypoxia, and proinflammatory cytokine release, all of which are stimuli for angiogenesis. We sought to determine whether A fumigatus directly modulates angiogenesis. A fumigatus culture filtrates profoundly inhibited the differentiation, migration, and capillary tube formation of human umbilical vein endothelial cells in vitro. To measure angiogenesis at the site of infection, we devised an in vivo Matrigel assay in cyclophosphamide-treated BALB/c mice with cutaneous invasive aspergillosis. Angiogenesis was significantly suppressed in Matrigel plugs implanted in A fumigatus–infected mice compared with plugs from uninfected control mice. The antiangiogenic effect of A fumigatus was completely abolished by deletion of the global regulator of secondary metabolism, laeA, and to a lesser extent by deletion of gliP, which controls gliotoxin production. Moreover, pure gliotoxin potently inhibited angiogenesis in vitro in a dose-dependent manner. Finally, overexpression of multiple angiogenesis mediator–encoding genes was observed in the lungs of cortisone-treated mice during early invasive aspergillosis, whereas gene expression returned rapidly to baseline levels in cyclophosphamide/cortisone-treated mice. Taken together, these results indicate that suppression of angiogenesis by A fumigatus both in vitro and in a neutropenic mouse model is mediated through secondary metabolite production.

scholarly journals A Genomic Comparison of in vivo and in vitro Brain Microvascular Endothelial Cells

2007 ◽  
Vol 28 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Anthony R Calabria ◽  
Eric V Shusta
Keyword(s):  
Endothelial Cells ◽  
Quantitative Polymerase Chain Reaction ◽  
Genomic Analysis ◽  
Subtractive Hybridization ◽  
Gene Panel ◽  
Microvascular Endothelial Cells ◽  
Brain Microvascular Endothelial Cells ◽  
Microvascular Endothelial

The blood—brain barrier (BBB) is composed of uniquely differentiated brain microvascular endothelial cells (BMEC). Often, it is of interest to replicate these attributes in the form of an in vitro model, and such models are widely used in the research community. However, the BMEC used to create in vitro BBB models de-differentiate in culture and lose many specialized characteristics. These changes are poorly understood at a molecular level, and little is known regarding the consequences of removing BMEC from their local in vivo microenvironment. To address these issues, suppression subtractive hybridization (SSH) was used to identify 25 gene transcripts that were differentially expressed between in vivo and in vitro BMEC. Genes affected included those involved in angiogenesis, transport and neurogenesis, and real-time quantitative polymerase chain reaction (qPCR) verified transcripts were primarily and significantly downregulated. Since this quantitative gene panel represented those BMEC characteristics lost upon culture, we used it to assess how culture manipulation, specifically BMEC purification and barrier induction by hydrocortisone, influenced the quality of in vitro models. Puromycin purification of BMEC elicited minimal differences compared with untreated BMEC, as assessed by qPCR. In contrast, qPCR-based gene panel analysis after induction with hydrocortisone indicated a modest shift of 10 of the 23 genes toward a more ‘ in vivo-like’ gene expression profile, which correlated with improved barrier phenotype. Genomic analysis of BMEC de-differentiation in culture has thus yielded a functionally diverse set of genes useful for comparing the in vitro and in vivo BBB.

scholarly journals Dolosigranulum pigrum Cooperation and Competition in Human Nasal Microbiota

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Silvio D. Brugger ◽  
Sara M. Eslami ◽  
Melinda M. Pettigrew ◽  
Isabel F. Escapa ◽  
Matthew T. Henke ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Genomic Analysis ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Microbe Interactions ◽  
Clinical Experiments ◽  
Nasal Microbiota

ABSTRACT Multiple epidemiological studies identify Dolosigranulum pigrum as a candidate beneficial bacterium based on its positive association with health, including negative associations with nasal/nasopharyngeal colonization by the pathogenic species Staphylococcus aureus and Streptococcus pneumoniae. Using a multipronged approach to gain new insights into D. pigrum function, we observed phenotypic interactions and predictions of genomic capacity that support the idea of a role for microbe-microbe interactions involving D. pigrum in shaping the composition of human nasal microbiota. We identified in vivo community-level and in vitro phenotypic cooperation by specific nasal Corynebacterium species. Also, D. pigrum inhibited S. aureus growth in vitro, whereas robust inhibition of S. pneumoniae required both D. pigrum and a nasal Corynebacterium together. D. pigrum l-lactic acid production was insufficient to account for these inhibitions. Genomic analysis of 11 strains revealed that D. pigrum has a small genome (average 1.86 Mb) and multiple predicted auxotrophies consistent with D. pigrum relying on its human host and on cocolonizing bacteria for key nutrients. Further, the accessory genome of D. pigrum harbored a diverse repertoire of biosynthetic gene clusters, some of which may have a role in microbe-microbe interactions. These new insights into D. pigrum’s functions advance the field from compositional analysis to genomic and phenotypic experimentation on a potentially beneficial bacterial resident of the human upper respiratory tract and lay the foundation for future animal and clinical experiments. IMPORTANCE Staphylococcus aureus and Streptococcus pneumoniae infections cause significant morbidity and mortality in humans. For both, nasal colonization is a risk factor for infection. Studies of nasal microbiota identify Dolosigranulum pigrum as a benign bacterium present when adults are free of S. aureus or when children are free of S. pneumoniae. Here, we validated these in vivo associations with functional assays. We found that D. pigrum inhibited S. aureus in vitro and, together with a specific nasal Corynebacterium species, also inhibited S. pneumoniae. Furthermore, genomic analysis of D. pigrum indicated that it must obtain key nutrients from other nasal bacteria or from humans. These phenotypic interactions support the idea of a role for microbe-microbe interactions in shaping the composition of human nasal microbiota and implicate D. pigrum as a mutualist of humans. These findings support the feasibility of future development of microbe-targeted interventions to reshape nasal microbiota composition to exclude S. aureus and/or S. pneumoniae.

Pilot study of a comprehensive precision medicine platform for children with high-risk cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10539-10539 ◽  
Author(s):  
Loretta Lau ◽  
Jennifer Byrne ◽  
Paul G Ekert ◽  
Tim Failes ◽  
Andrew Fellowes ◽  
...  
Keyword(s):  
Pilot Study ◽  
High Risk ◽  
Precision Medicine ◽  
Drug Testing ◽  
National Level ◽  
Genomic Analysis ◽  
Treatment Recommendations ◽  
Childhood Cancers

10539 Background: Genomic analyses can identify actionable mutations in a subset of childhood cancers. However it has been challenging to translate actionable mutations into substantial benefits for adult cancers despite high mutation frequency. Methods: To test whether we could enhance identification of personalised therapies for high risk (HR) childhood cancers we conducted a pilot study (TARGET) evaluating a novel, comprehensive precision medicine platform incorporating molecular profiling, in vitro and in vivo drug testing. Results: We evaluated the first 29 patients with HR cancer (expected survival < 30%) enrolled prospectively over 15 months. Samples were collected from 15 CNS tumors, 10 solid tumors and 4 leukemias. All samples underwent targeted DNA sequencing. Pathogenic or likely pathogenic mutations were found in 59% (17/29) of tumors. 41% (12/29) had potentially actionable mutations. RNA-sequencing was performed on 27 samples. Previously described fusions were identified in 19% (5/27; 1 targetable, 1 clinical relevant and 3 diagnostic fusions). 37% (10/27) of samples also had actionable aberrations related to copy number changes or RNA expression. In vitro culture and establishment of patient-derived xenograft (PDX) were attempted in 19 and 21 fresh samples, respectively. The success rate of establishing a primary culture was 42% (8/19) and PDX engraftment rate was 67% (14/21). At least 1 drug hit was identified in 5 (56%) of the 9 samples screened using a high throughput drug screen of up to 165 compounds. Drug testing has been completed in 4 PDXs and was informative in all 4 cases allowing prioritisation of treatment recommendations. Genomic analysis in combination with RNA-seq, in vitro drug screening and PDX drug testing enriched the analysis and increased the ability to make personalised treatment recommendations from 41% (targeted panel alone) to 66%. Conclusions: This pilot study demonstrates that this novel, comprehensive platform is feasible and has the potential to improve outcome for HR childhood cancers. A multicentre study testing the implementation of the platform on a national level (PRISM trial) will open for Australian children with HR cancer under the Zero Childhood Cancer Program in 2017.

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