Telacebec for ultra-short treatment of Buruli ulcer in a mouse model [Clinical Therapeutics]
Telacebec (Q203) is a new anti-tubercular drug with extremely potent activity against Mycobacterium ulcerans. Here, we explored the treatment-shortening potential of Q203 alone or in combination with rifampin (RIF) in a mouse footpad infection model. The first study compared Q203 at 5 and 10 mg/kg doses alone and with rifampin. Q203 alone rendered most mouse footpads culture-negative in 2 weeks. Combining Q203 with rifampin resulted in relapse-free cure 24 weeks after completing 2 weeks of treatment, compared to a 25% relapse rate in mice receiving RIF+clarithromycin, the current standard of care, for 4 weeks.
The second study explored the dose-ranging activity of Q203 alone and with RIF, including the extended activity of Q203 after treatment discontinuation. The bactericidal activity of Q203 persisted for ≥ 4 weeks beyond the last dose. All mice receiving just 1 week of Q203 at 2-10 mg/kg were culture-negative 4 weeks after stopping treatment. Mice receiving 2 weeks of Q203 at 0.5, 2 and 10 mg/kg were culture-negative 4 weeks after treatment. RIF did not increase the efficacy of Q203. A pharmacokinetics sub-study revealed that Q203 doses of 2-10 mg/kg in mice produce plasma concentrations similar to those produced by 100-300 mg doses in humans, with no adverse effect of RIF on Q203 concentrations.
These results indicate the extraordinary potential of Q203 to reduce the duration of treatment necessary for cure to ≤ 1 week (or 5 doses of 2-10 mg/kg) in our mouse footpad infection model and warrant further evaluation of Q203 in clinical trials.
Fosmanogepix (APX001) is Effective in the Treatment of Pulmonary Murine Mucormycosis Due to Rhizopus arrhizus [Experimental Therapeutics]
Mucormycosis is a life-threatening infection with high mortality that occurs predominantly in immunocompromised patients. Manogepix (MGX) is a novel antifungal that targets Gwt1, an early step in the conserved glycosylphosphotidyl inositol (GPI) post-translational modification pathway of surface proteins in eukaryotic cells. Inhibition of inositol acylation by MGX results in pleiotropic effects including inhibition of maturation of GPI-anchored proteins necessary for growth and virulence. MGX has been previously shown to have in vitro activity against some strains of Mucorales. Here we assessed the in vivo activity of the prodrug fosmanogepix, currently in clinical development for the treatment of invasive fungal infections, against two Rhizopus arrhizus strains with high (4.0 μg/ml) and low (0.25 μg/ml) minimum effective concentration (MEC) values. In both invasive pulmonary infection models, treatment of mice with 78 mg/kg or 104 mg/kg fosmanogepix, along with 1-aminobenzotriazole to enhance the serum half-live of MGX in mice, significantly increased median survival time and prolonged overall survival by day 21 post infection when compared to placebo. In addition, administration of fosmanogepix resulted in a 1-2 log reduction in both lung and kidney fungal burden. For the 104 mg/kg fosmanogepix dose, tissue clearance and survival were comparable to clinically relevant doses of isavuconazole (ISA), which is FDA approved for the treatment of mucormycosis. These results support continued development of fosmanogepix as a first in class treatment for invasive mucormycosis.
Structure and molecular recognition mechanism of IMP-13 metallo-{beta}-lactamase [Mechanisms of Resistance]
Multi-drug resistance among Gram-negative bacteria is a major global public health threat. Metallo-β-lactamases (MBLs) target the most widely-used antibiotic class, the β-lactams, including the most recent-generation carbapenems. Interspecies spread renders these enzymes a serious clinical threat and there are no clinically-available inhibitors. We present crystal structures of IMP-13, a structurally-uncharacterized MBL from Gram-negative Pseudomonas aerugionasa found in clinical outbreaks globally, and characterize the binding using solution NMR-spectroscopy and molecular-dynamics simulations. Crystal structures of apo IMP-13 and bound to four clinically-relevant carbapenem antibiotics (doripenem, ertapenem, imipenem and meropenem) are presented. Active site plasticity and the active-site loop, where a tryptophan residue stabilizes the antibiotic core scaffold, are essential to the substrate-binding mechanism. The conserved carbapenem scaffold plays the most significant role in IMP-13 binding, explaining the broad substrate specificity. The observed plasticity and substrate-locking mechanism provide opportunities for rational drug design of novel metallo-β-lactamase inhibitors, essential in the fight against antibiotic resistance.
A Comparison of Clinical Outcomes among Intensive Care Unit Patients Receiving Ceftriaxone 1 gram daily or 2 grams daily [Clinical Therapeutics]
Background: Intensive care unit (ICU) patients may experience ceftriaxone underexposure but clinical outcomes data are lacking. The objective of this study was to determine the impact of ceftriaxone dosing on clinical outcomes amongst ICU patients without central nervous system (CNS) infection.
Methods: A retrospective study of ICU patients receiving intravenous, empiric ceftriaxone for non-CNS infections was conducted. Patients ≥18 years of age who received ≤2 grams of ceftriaxone daily for ≥72 hours were included and categorized as receiving ceftriaxone 1 gram or 2 grams daily. The primary, composite outcome was treatment failure: inpatient mortality and/or antibiotic escalation due to clinical worsening. Propensity score matching was performed based on the probability of receiving ceftriaxone 2 grams daily. Multivariable logistic regression determined the association between ceftriaxone dose and treatment failure in a propensity-matched cohort.
Results: A total of 212 patients were included in the propensity-matched cohort. The most common diagnoses (83.0%) were pneumonia and urinary tract infection. Treatment failure occurred in 17.0% and 5.7% of patients receiving 1 gram and 2 grams daily, respectively (p=0.0156). Overall inpatient mortality was 8.5%. Ceftriaxone 2 gram dosing was associated with a reduced likelihood of treatment failure (adjusted odds ratio=0.190; 95% confidence interval: 0.059 – 0.607). Other independent predictors of treatment failure included sequential organ failure assessment score (aOR 1.440, 95% CI 1.254 – 1.653) and creatinine clearance at 72 hours from ceftriaxone initiation (aOR 0.980, 95% CI (0.971 – 0.999).
Conclusions: Ceftriaxone 2 grams daily when used as appropriate antimicrobial coverage may be appropriate for ICU patients with lower mortality risk.
The Als3 cell wall adhesin plays a critical role in human Serum amyloid A1 (SAA1)-induced cell death and aggregation in Candida albicans [Mechanisms of Resistance]
Antimicrobial peptides and proteins play critical roles in the host defense against invading pathogens. We recently discovered that recombinantly expressed human and mouse serum amyloid A1 (rhSAA1 and rmSAA1) proteins have potent antifungal activities against the major human fungal pathogen Candida albicans. At high concentrations, rhSAA1 disrupts C. albicans membrane integrity and induces rapid fungal cell death. In the current study, we find that rhSAA1 promotes cell aggregation and targets the C. albicans cell wall adhesin Als3. Inactivation of ALS3 in C. albicans leads to a striking decrease in cell aggregation and cell death upon rhSAA1 treatment, suggesting that Als3 plays a critical role in SAA1 sensing. We further demonstrate that deletion of the transcriptional regulators controlling the expression of ALS3, such as AHR1, BCR1, and EFG1 in C. albicans results in similar effects to that of the als3/als3 mutant upon rhSAA1 treatment. Global gene expression profiling indicates that rhSAA1 has a discernible impact on the expression of cell wall- and metabolism-related genes, suggesting that rhSAA1 treatment could lead to a nutrient starvation effect on C. albicans cells.
Ceftobiprole Activity against Bacteria from Skin and Skin Structure Infections in the United States from 2016 through 2018 [Susceptibility]
Ceftobiprole medocaril is an advanced-generation cephalosporin prodrug that has qualified infectious disease product status granted by the US-FDA and is currently being evaluated in phase 3 clinical trials in patients with acute bacterial skin and skin structure infections (ABSSSIs) and in patients with Staphylococcus aureus bacteremia. In this study, the activity of ceftobiprole and comparators was evaluated against more than 7,300 clinical isolates collected in the United States from 2016 through 2018 from patients with skin and skin structure infections. The major species/pathogen groups were S. aureus (53%), Enterobacterales (23%), Pseudomonas aeruginosa (7%), β-hemolytic streptococci (6%), Enterococcus spp. (4%), and coagulase-negative staphylococci (2%). Ceftobiprole was highly active against S. aureus (MIC50/90, 0.5/1 mg/L; 99.7% susceptible by EUCAST criteria; 42% methicillin-resistant S. aureus [lsqb]MRSA[rsqb]). Ceftobiprole also exhibited potent activity against other Gram-positive cocci. The overall susceptibility of Enterobacterales to ceftobiprole was 84.8% (>99.0% susceptible for isolate subsets that exhibited a non-extended-spectrum β-lactamase [lsqb]ESBL[rsqb]-phenotype). A total of 74.4% of P. aeruginosa, 100% of β-hemolytic streptococci and coagulase-negative staphylococci, and 99.6% of Enterococcus faecalis isolates were inhibited by ceftobiprole at ≤4 mg/L. As expected, ceftobiprole was largely inactive against Enterobacterales that contained ESBL genes and Enterococcus faecium. Overall, ceftobiprole was highly active against most clinical isolates from the major Gram-positive and Gram-negative skin and skin structure pathogen groups collected at U.S. medical centers participating in the SENTRY Antimicrobial Surveillance Program during 2016–2018. The broad-spectrum activity of ceftobiprole, including potent activity against MRSA, supports its further evaluation for the potential ABSSSI indication.
Combination Therapy with Ibrexafungerp (formerly SCY-078), a First-in-Class Triterpenoid Inhibitor of (1->3)-{beta}-D-Glucan Synthesis, and Isavuconazole for Treatment of Experimental Invasive Pulmonary Aspergillosis [Experimental Therapeutics]
Ibrexafungerp (formerly SCY-078) is a semisynthetic triterpenoid and potent (1->3)-β-D-glucan synthase inhibitor. We investigated the in vitro activity, pharmacokinetics, and in vivo efficacy of ibrexafungerp (SCY) alone and in combination with anti-mould triazole isavuconazole (ISA) against invasive pulmonary aspergillosis (IPA). The combination of ibrexafungerp and isavuconazole in in vitro studies resulted in an additive and synergistic interactions against Aspergillus spp. Plasma concentration-time curves of ibrexafungerp were compatible with linear dose proportional profile. In vivo efficacy was studied in a well established persistently neutropenic NZW rabbit model of experimental IPA. Treatment groups included untreated rabbits (UC) and rabbits receiving ibrexafungerp at 2.5(SCY2.5) and 7.5(SCY7.5) mg/kg/day, isavuconazole at 40(ISA40) mg/kg/day, or combinations of SCY2.5+ISA40 and SCY7.5+ISA40. The combination of SCY+ISA produced in vitro synergistic interaction. There was significant in vivo reduction of residual fungal burden, lung weights, and pulmonary infarct scores in SCY2.5+ISA40, SCY7.5+ISA40, and ISA40-treatment groups vs that of SCY2.5-treated, SCY7.5-treated and UC (p<0.01). Rabbits treated with SCY2.5+ISA40 and SCY7.5+ISA40 had prolonged survival in comparison to that of SCY2.5-, SCY7.5-, ISA40-treated or UC (p<0.05). Serum GMI and (1->3)-β-D-glucan levels significantly declined in animals treated with the combination of SCY7.5+ISA40 in comparison to those treated with SCY7.5 or ISA40 (p<0.05). Ibrexafungerp and isavuconazole combination demonstrated prolonged survival, decreased pulmonary injury, reduced residual fungal burden, lower GMI and (1->3)-β-D-glucan levels in comparison to those of single therapy for treatment of IPA. These findings provide an experimental foundation for clinical evaluation of the combination of ibrexafungerp and an anti-mould triazole for treatment of IPA.
ZN148 - a modular synthetic metallo-{beta}-lactamase inhibitor reverses carbapenem-resistance in Gram-negative pathogens in vivo [Experimental Therapeutics]
Carbapenem-resistant Gram-negative pathogens are a critical public health threat and there is an urgent need for new treatments. Carbapenemases (β-lactamases able to inactivate carbapenems) have been identified in both serine β-lactamase (SBL) and metallo β-lactamase (MBL) families. The recent introduction of SBL carbapenemase-inhibitors has provided alternative therapeutic options. Unfortunately, there are no approved inhibitors of MBL-mediated carbapenem-resistance and treatment options for infections caused by MBL-producing Gram-negatives are limited. Here, we present ZN148, a zinc-chelating MBL-inhibitor capable of restoring the bactericidal effect of meropenem and in vitro clinical susceptibility to carbapenems in >98% of a large international collection of MBL-producing clinical Enterobacterales strains (n=234). Moreover, ZN148 was able to potentiate the effect of meropenem against NDM-1-producing Klebsiella pneumoniae in a murine neutropenic peritonitis model. ZN148 showed no inhibition of the human zinc-containing enzyme glyoxylase II at 500 μM and no acute toxicity was observed in an in vivo mouse model with cumulative dosages up to 128 mg/kg. Biochemical analysis showed a time-dependent inhibition of MBLs by ZN148 and removal of zinc ions from the active site. Addition of exogenous zinc after ZN148 exposure only restored MBL activity by ~30%, suggesting an irreversible mechanism of inhibition. Mass-spectrometry and molecular modelling indicated potential oxidation of the active site Cys221 residue. Overall, these results demonstrate the therapeutic potential of a ZN148-carbapenem combination against MBL-producing Gram-negative pathogens and that ZN148 is a highly promising MBL inhibitor, capable of operating in a functional space not presently filled by any clinically approved compound.
Comparison of Cefepime/Cefpirome and Carbapenem Therapy for Acinetobacter Bloodstream Infection: A Multicentre Study [Clinical Therapeutics]
Carbapenems are currently the preferred agents for the treatment of serious Acinetobacter infections. However, whether cefepime/cefpirome can be used to treat Acinetobacter bloodstream infection (BSI) if it is active against the causative pathogens is not clear. This study aimed to compare the efficacy of cefepime/cefpirome and carbapenem monotherapy in patients with Acinetobacter BSI. The population included 360 patients with monomicrobial Acinetobacter BSI receiving appropriate antimicrobial therapy admitted to four medical centres in Taiwan in 2012–2017. The predictors of 30-day mortality were determined by Cox regression analysis. The overall 30-day mortality rate in the appropriate antibiotic treatment group was 25.0% (90/360 patients), respectively. The crude 30-day mortality rates for cefepime/cefpirome and carbapenem therapy were 11.5% (7/61 patients) and 26.3% (21/80 patients), respectively. The patients receiving cefepime/cefpirome/carbapenem therapy were infected by Acinetobacter nosocomialis (51.8%), A. baumannii (18.4%) and A. pittii (12.1%). After adjusting for age, Sequential Organ Failure Assessment (SOFA) score, invasive procedures, and underlying diseases, cefepime/cefpirome therapy was not independently associated with a higher or lower 30-day mortality compared to the carbapenem therapy. SOFA score (hazard ratio [HR], 1.324; 95% confidence interval [CI], 1.137–1.543; P < 0.001) and neutropenia (HR, 7.060; 95% CI, 1.607–31.019; P = 0.010) were independent risk factors for 30-day mortality of patients receiving cefepime/cefpirome or carbapenem monotherapy. The incidence density of 30-day mortality for cefepime/cefpirome versus carbapenem therapy was 0.40% versus 1.04%. The therapeutic response of cefepime/cefpirome therapy was comparable to that of carbapenems among patients with Acinetobacter BSI receiving appropriate antimicrobial therapy.
Stp1 loss of function promotes {beta}-lactam resistance in S. aureus that is independent of classical genes [Mechanisms of Resistance]
β-lactam resistance in Staphylococcus aureus limits treatment options. Stp1 and Stk1, a serine-threonine phosphatase and kinase respectively, mediate serine-threonine kinase (STK) signaling. Loss of function point mutations in stp1 were detected among laboratory passaged, β-lactam resistant S. aureus strains lacking mecA and blaZ, the major determinants of β-lactam resistance in the bacteria. Loss of Stp1 function facilitates β-lactam resistance of the bacteria.
Evaluation of the efficacy of antibiotic combinations against multidrug-resistant Pseudomonas aeruginosa in automated time-lapse microscopy and static time-kill experiments [Clinical Therapeutics]
Objectives: Antibiotic combination therapy is used for severe infections caused by multidrug-resistant (MDR) Gram-negative bacteria. Yet, data of which combinations are most effective is lacking. This study aimed to evaluate the in vitro efficacy of polymyxin B in combination with 13 other antibiotics against four clinical strains of MDR Pseudomonas aeruginosa.
Methods: We evaluated the interactions of polymyxin B in combination with amikacin, aztreonam, cefepime, chloramphenicol, ciprofloxacin, fosfomycin, meropenem, minocycline, rifampicin, temocillin, thiamphenicol or trimethoprim by automated time-lapse microscopy using predefined cut-off values indicating inhibition of growth (≤106 CFU/mL) at 24 h. Promising combinations were subsequently evaluated in static time-kill experiments.
Results: All strains were intermediate or resistant to polymyxin B, anti-pseudomonal β-lactams, ciprofloxacin and amikacin. Genes encoding β-lactamases (e.g., blaPAO and blaOXA-50) and mutations associated with permeability and efflux were detected in all strains. In the time-lapse microscopy experiments, positive interactions were found with 39 of 52 antibiotic combination/bacterial strain setups. Enhanced activity was found against all four strains with polymyxin B used in combination with aztreonam, cefepime, fosfomycin, minocycline, thiamphenicol and trimethoprim. Time kill experiments showed additive or synergistic activity with 27 of the 39 tested polymyxin B combinations, most frequently with aztreonam, cefepime, and meropenem.
Conclusion: Positive interactions were frequently found with the tested combinations, also against strains that harboured several resistance mechanisms to the single drugs and with antibiotics that are normally not active against P. aeruginosa. Further study is needed to explore the clinical utility of these combinations.
Significant efficacy of single low dose primaquine compared to stand alone artemisinin combination therapy in reducing gametocyte carriage in Cambodian patients with uncomplicated multidrug resistant Plasmodium falciparum malaria [Epidemiology and Surveil
Since 2012, single low dose of primaquine (SLDPQ, 0.25mg/kg) has been recommended with artemisinin-based combination therapies, as first-line treatment of acute uncomplicated Plasmodium falciparum malaria, to interrupt its transmission, especially in low transmission settings of multidrug, including artemisinin, resistance. Policy makers in Cambodia have been reluctant to implement this recommendation due to primaquine safety concerns and lack of data on its efficacy.
In this randomized controlled trial, 109 Cambodians with acute uncomplicated P. falciparum malaria received dihydroartemisinin-piperaquine (DP) alone or combined with SLDPQ on the first treatment day. Transmission-blocking efficacy of SLDPQ was evaluated on Days 0, 1, 2, 3, 7, 14, 21, 28 and recrudescence by reverse transcriptase polymerase chain reaction (RT-PCR) (gametocyte prevalence) and membrane-feeding assays with Anopheles minimus mosquitoes (gametocyte infectivity). Without the influence of recrudescent infections, DP+SLDPQ reduced gametocyte carriage 3 fold compared to DP. Of 48 patients tested on Day 0, only three patients were infectious to mosquitoes (~6%). Post-treatment, three patients were infectious: on D14 (3.5%, 1/29), and on the first and seventh day of recrudescence (8.3%, 1/12 for each); this overall low infectivity precluded our ability to assess its transmission blocking efficacy.
Our study confirms effective gametocyte clearance of SLDPQ when combined with DP in multidrug resistant P. falciparum and the negative impact of recrudescent infections due to poor DP efficacy. Artesunate-mefloquine (ASMQ) has replaced DP and ASMQ-SLDPQ has been deployed to treat all P. falciparum symptomatic patients to further support the elimination of multidrug resistant P. falciparum in Cambodia.
MK-571, a cysteinyl leukotriene receptor-1 antagonist, inhibits hepatitis C virus (HCV) replication [Antiviral Agents]
The quinoline MK-571 is the most commonly used inhibitor of multidrug resistance protein-1 (MRP-1) but was originally developed as a cysteinyl leukotriene receptor 1 (CysLTR1) antagonist. While studying the modulatory effect of MRP-1 on anti-hepatitis C virus (HCV) direct acting-antivirals (DAA) efficiency, we observed an unexpected anti-HCV effect of compound MK-571 alone. This anti-HCV activity was characterized in Huh7.5 cells stably harboring a subgenomic genotype 1b replicon. A dose-dependent decrease of HCV RNA levels was observed upon MK-571 administration, with an EC50 of 9±0.3 μM and a maximum HCV RNA level reduction of approximatively 1 Log10. MK-571 also reduced the replication of the HCV full-length J6/JFH1 model in a dose-dependent manner. However, probenecid and apigenin homodimer (APN), two specific inhibitors of MRP-1, had no effect on HCV replication. In contrast, the CysLTR1 antagonists SR2640 increased HCV-SGR RNA levels in a dose-dependent manner, with a maximum increase of 10-fold. In addition, a combination of natural CysLTR1 agonist (LTD4) or antagonists (zafirlukast, cinalukast, and SR2640) with MK-571 completely reversed its antiviral effect, suggesting its anti-HCV activity is related to CysLTR1 rather to MRP-1 inhibition. In conclusion, we showed that MK-571 inhibits HCV replication in hepatoma cell cultures by acting as a CysLTR1 receptor antagonist, thus unraveling a new host-virus interaction in the HCV life cycle.
An engineered double lipid II binding motifs-containing lantibiotic displays potent and selective antimicrobial activity against E. faecium [Chemistry; Biosynthesis]
Lipid II is an essential precursor of the bacterial cell wall biosynthesis and thereby an important target for various antibiotics. Several lanthionine-containing peptide antibiotics target lipid II with lanthionine-stabilized lipid II-binding motifs. Here, we used the biosynthesis system of the lantibiotic nisin to synthesize a two lipid II binding motifs-containing lantibiotic, termed TL19, which contains the N-terminal lipid II binding motif of nisin and the distinct C-terminal lipid II binding motif of one peptide of the two-component haloduracin (i.e. HalA1). Further characterization demonstrated that (i) TL19 exerts 64-fold stronger antimicrobial activity against E. faecium than nisin (1-22), which has only one lipid II binding site, and (ii) both the N- and C-terminal domains are essential for the potent antimicrobial activity of TL19, as evidenced by mutagenesis of each single and double domains. These results show the feasibility of a new approach to synthesize potent lantibiotics with two different lipid II binding motifs to treat specific antibiotic-resistant pathogens.
Effect of drug pressure on promoting the emergence of antimalarial resistant parasites among pregnant women in Ghana [Mechanisms of Resistance]
Continuous spread of antimalarial drug resistance is a threat to current chemotherapy efficacy. Therefore, characterizing the genetic diversity of drug resistance markers is needed to follow treatment effectiveness and further update control strategies. Here, we genotyped Plasmodium falciparum resistance gene markers associated with sulfadoxine-pyrimethamine (SP) and artemisinin-based combination therapy (ACT) in isolates from pregnant women in Ghana. The prevalence of the septuple
A histone methyltransferase inhibitor can reverse epigenetically acquired drug resistance in the malaria parasite Plasmodium falciparum [Mechanisms of Resistance]
Malaria parasites invade and replicate within red blood cells (RBCs), extensively modifying their structure and gaining access to the extracellular environment by placing the plasmodial surface anion channel (PSAC) into the RBC membrane. Expression of members of the cytoadherence linked antigen gene 3 (clag3) family is required for PSAC activity, a process that is regulated epigenetically. PSAC is a well-established route of uptake for large, hydrophilic antimalarial compounds and parasites can acquire resistance by silencing clag3 gene expression, thereby reducing drug uptake. We found that exposure to sub-IC50 concentrations of the histone methyltransferase inhibitor chaetocin caused substantial changes in both clag3 gene expression and RBC permeability, reversing acquired resistance to the antimalarial compound blasticidin S that is transported through PSAC. Chaetocin treatment also altered progression of parasites through their replicative cycle, presumably by changing their ability to modify chromatin appropriately to enable DNA replication. These results indicate that targeting histone modifiers could represent a novel tool for reversing epigenetically acquired drug resistance in P. falciparum.
In Vitro and In Vivo Characterization of Potent Antileishmanial Methionine Aminopeptidase-1 Inhibitors [Experimental Therapeutics]
Leishmania major is the causative agent of cutaneous leishmaniasis (CL). No human vaccine is available for CL and current drug regimens present several drawbacks such as emerging resistance, severe toxicity, medium effectiveness, and/or high cost. Thus, the need for better treatment options against CL is a priority. In the present study, we validate the enzyme methionine aminopeptidase-1 (MetAP1), a metalloprotease that catalyzes the removal of N-terminal methionine from peptides and proteins, as a chemotherapeutic target against CL infection. The in vitro antileishmanial activity of eight novel MetAP1 inhibitors (OJT001-OJT008) were investigated. Three compounds OJT006, OJT007, and OJT008 demonstrated potent anti-proliferative effect in macrophages infected with L. major amastigotes and promastigotes at submicromolar concentrations, with no cytotoxicity against host cells. Importantly, the leishmanicidal effect was diminished by almost 10-fold in transgenic L. major promastigotes overexpressing MetAP1LM in comparison to wild-type promastigotes. Furthermore, the in vivo activity of OJT006, OJT007, and OJT008 were investigated in L. major-infected BALB/c mice. In comparison to the control group, OJT008 significantly decreased footpad parasite load by 86%, and exhibited no toxicity against in treated mice. We propose MetAP1 inhibitor OJT008 as a potential chemotherapeutic candidate against CL infection caused by L. major infection.
Biochemical Characterization of QPX7728, a New Ultra-Broad-Spectrum Beta-lactamase Inhibitor of Serine and Metallo-Beta-Lactamases [Mechanisms of Resistance]
QPX7728 is a new ultra-broad-spectrum inhibitor of serine and metallo beta-lactamases from a class of cyclic boronates that gave rise to vaborbactam. The spectrum and mechanism of beta-lactamase inhibition by QPX7728 were assessed using purified enzymes from all molecular classes. QPX7728 inhibits class A ESBLs (IC50 range 1-3 nM) and carbapenemases such as KPC (IC50 2.9±0.4 nM) as well as class C P99 (IC50 of 22±8 nM) with a potency that is comparable or higher than recently FDA approved BLIs avibactam, relebactam and vaborbactam. Unlike those other BLIs, QPX7728 is also a potent inhibitor of class D carbapenemases such as OXA-48 from Enterobacteriaceae and OXA enzymes from A. baumannii (OXA-23/24/58, IC50 range 1-2 nM) as well as MBLs such as NDM-1 (IC50 55±25 nM), VIM-1 (IC50 14±4 nM) and IMP-1 (IC50 610±70 nM). Inhibition of serine enzymes by QPX7728 is associated with progressive inactivation with a high efficiency k2/K ranging from of 6.3 x 104 (for P99) to 9.9 x 105 M-1 s-1 (for OXA-23). This inhibition is reversible with variable stability of the QPX7728-beta-lactamase complexes with target residence time ranging from minutes to several hours: 5-20 minutes for OXA carbapenemases from A. baumanii, ~50 minutes for OXA-48 and 2-3 hours for KPC and CTX-M-15. QPX7728 inhibited all tested serine enzymes at 1:1 molar ratio. Metallo-beta-lactamases NDM, VIM, and IMP were inhibited by a competitive mechanism with fast-on-fast-off kinetics, with Kis of 7.5±2.1 nM, 32±14 nM and 240±30 nM for VIM-1, NDM-1 and IMP-1, respectively. QPX7728 ultra-broad-spectrum of BLI inhibition combined with its high potency enables combinations with multiple different beta-lactam antibiotics.
Assessment of drug resistance during phase 2b clinical trials of presatovir in adults naturally infected with respiratory syncytial virus [Antiviral Agents]
Background: This study summarizes drug resistance analyses in 4 recent phase 2b trials of the respiratory syncytial virus (RSV) fusion inhibitor presatovir in naturally infected adults.
Methods: Adult hematopoietic cell transplant (HCT) recipients, lung transplant recipients, or hospitalized patients with naturally acquired, laboratory-confirmed RSV infection were enrolled in 4 randomized, double-blind, placebo-controlled studies with study-specific presatovir dosing. Full-length RSV F sequences amplified from nasal swabs obtained at baseline and postbaseline were analyzed by population sequencing. Substitutions at RSV fusion inhibitor resistance-associated positions are reported.
Results: Genotypic analyses were performed on 233 presatovir-treated and 149 placebo-treated subjects. RSV F variant V127A was present in 8 subjects at baseline. Population sequencing detected treatment-emergent substitutions in 10/89 (11.2%) HCT recipients with upper and 6/29 (20.7%) with lower respiratory tract infection, 1/35 (2.9%) lung transplant recipients, and 1/80 (1.3%) hospitalized patients treated with presatovir; placebo-treated subjects had no emergent resistance-associated substitutions. Subjects with substitutions at resistance-associated positions had smaller decreases in viral load during treatment relative to those without, but similar clinical outcomes.
Conclusions: Subject population type and dosing regimen may have influenced RSV resistance development during presatovir treatment. Subjects with vs without genotypic resistance development had decreased virologic responses but comparable clinical outcomes.
Efficacy of early oral switch with beta-lactams for low-risk Staphylococcus aureus bacteremia. [Clinical Therapeutics]
Objectives. The aim of this study was to assess the safety of early oral switch (EOS) prior to 14 days for low-risk Staphylococcus aureus bacteremia (LR-SAB), which is the primary treatment strategy employed at our institution. Usually recommended therapy is 14 days of intravenous (IV) antibiotics.
Methods. All patients with SAB at our hospital were identified between 1 January 2014 and 31 December 2018. Those meeting low-risk criteria (healthcare-associated, no evidence of deep infection or demonstrated involvement of prosthetic material, and no further positive blood cultures after 72-hours) were included in the study. The primary outcome was occurrence of a SAB-related complication within 90 days.
Results. There were 469 SAB episodes during the study period, 100 (21%) of whom met inclusion criteria. EOS was performed in 84 patients. In this group, line infection was the source in 79%, methicillin-susceptible S. aureus caused 95% of SABs and 74% of patients received IV flucloxacillin. The median duration of IV and oral antibiotics in the EOS group was 5 (IQR 4-6) and 10 days (IQR 9-14), respectively. Seventy-one percent of patients received flucloxacillin as their EOS agent. Overall, 86% of oral step-down therapy was with beta-lactams. One patient (1%) undergoing EOS had SAB relapse within 90 days. No deaths attributable to SAB occurred within 90 days.
Conclusions. In this low MRSA prevalence LR-SAB cohort, EOS was associated with a low incidence of SAB-related complications. This was achieved with oral beta-lactam therapy in most patients. Larger prospective studies are needed to confirm these findings.
WITHDRAWN: Very strong synergy between modified RANTES and gp41 binding peptides leads to potent anti-HIV-1 activity [Article]
This article, published ahead of print on 28 July 2008, has been withdrawn by the authors. Although moderate synergy between P2-RANTES and C peptides can be observed with high statistical significance in cell fusion assays, this synergy was not able to be verified in HIV viral assays. The authors regret the overstatement of synergy and will revise the paper for publication at a later date.
Sundeck BBQs, trivia nights, and strict hygiene rules: An inside look at the life of crews locked down on luxury superyachts
Source: www.businessinsider.com - Saturday, May 09, 2020
Many superyacht crew members have been stuck on their vessels after lockdowns and travel bans were instated due to the coronavirus pandemic. We spoke to crew members who felt 'lucky' to be quarantined in such luxury digs — and grateful to still have jobs and secure wages. There is still plenty of work to be done, but workers also described trivia games, sundeck BBQs, and hot tub nights they're using to pass the time and bond with colleagues. Strict new hygiene and sanitation rules have also been put into place. Visit Business Insider's homepage for more stories . In late March, billionaire businessman David Geffen posted a shot on Instagram taken from his 452-foot superyacht Rising Sun. It was hastily deleted — but not before it had raised more than a few eyebrows and stirred discourse around the 1% and their self-isolation privilege. But it's not just the rare billionaire who is bunkering down on their yacht during the COVID-19 pandemic. Here is another group of people for whom this is a new reality: the yacht's crews. Before this crisis, there were around 80,000 people employed on pleasure craft around the globe, according to Laurence Lewis, CEO of YPI Crew, a yacht recruitment agency. As countries rushed to close their borders, ports were closed — and overnight, many found themselves unable to travel to get to or leave their yachts. For many, a superyacht sounds like the dream scenario to see out lockdown. But is it? "Ther
5 Things I Found On Ancipient.com
Source: ninetymilesfromtyranny.blogspot.com - Saturday, May 09, 2020
What is Ancipient.com ? It Is A Pro-American (Nationalist), Pro-Trump, Pro-American Exceptionalism, And Pro-Western Values automated news aggregation website. Ancipient.com is an automated, curated, rules based news aggregation website. If I wanted it to sound sexy, I could say it uses artificial intelligence to select news articles. It does not. It uses negative and positive keywords, data rules and curation to select news articles. When other news aggregaters have not updated any new news in hours, you can always depend on my trusty robot ancipient to work 24/7 to keep you updated. Ancipient is a new word, it means: an·cip·i·ent /anˈsipēənt/ adjective in an initial stage of understanding; beginning to understand or learn. "he could feel ancipient knowledge growing" (of a person) learning, and improving their understanding on a topic or topics. Oh Yeah, The Links I Promised: Russia, China spinning coronavirus conspiracies to blame West Georgetown sues US for not giving money to illegal immigrant families Release the hounds! Singapore deploys ROBOT DOG to help enforce social distancing (PHOTOS, VIDEO) 'Palestinian' Authority hiding terrorist salaries from donor countries in financial reports Sens. Cotton, Cruz, Hawley & Grassley Press Trump to Suspend Most Visas Take a look at Ancipient.com and check it out!
U.S. logs record high unemployment numbers - what comes next?
Source: www.nbcnews.com - Saturday, May 09, 2020
The U.S. unemployment rate reached 14.7 percent for April - the worst monthly rate since the Great Depression. The White House has projected optimism, saying they expect the economy to rocket upward once coronavirus restrictions are lifted. But many experts think that is not a realistic expectation.
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10 things you need to know today: May 9, 2020
Source: theweek.com - Saturday, May 09, 2020
1. The Labor Department on Friday said that 20.5 million jobs were lost in April, and the unemployment rate climbed to 14.7 percent. The staggering report showed that a decade of job gains were wiped out in just one month. The report also notes that if it included workers classified as furloughed or temporarily laid off, "the overall unemployment rate would have been almost 5 percentage points higher than reported." The Labor Department's March report showed the unemployment rate climbing to 4.4 percent, from 3.5 percent in February. Weekly data previously showed that more than 33 million Americans have filed initial jobless claims over the course of seven weeks, a number that's equivalent to about 21 percent of the labor force. The ADP National Employment Report also said earlier this week that 20.2 million private sector jobs were lost from March to April. President Trump, who was live on Fox & Friends the moment the report was released, described the unemployment numbers as "fully expected" and "no surprise." [ U.S. Bureau of Labor Statistics , The Washington Post ] 2. The Office of Special Counsel is recommending that ousted vaccine official Dr. Rick Bright be reinstated while it investigates his case, his lawyers announced Friday. Bright, while leading coronavirus vaccine development, was recently removed from his position as the director of the Department of Health and Human Services' Biomedical Advanced Research and Devel
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As dating apps try to pivot to virtual events, some users are trying to get people to violate social distancing rules
Source: www.businessinsider.com - Saturday, May 09, 2020
Dating apps like Tinder, Bumble, and Hinge have reported increased use amid the coronavirus pandemic, while touting virtual dating alternatives for users instead of meeting up in person. Swaths of users are still encouraging matches to break quarantine to have sex and go on dates, despite social distancing guidelines and fines to comply with them. An illustrator on Instagram has been collecting screenshots of these situations, and told Business Insider that users will brand themselves as "badasses," dispute the effectiveness of isolating, and lash out in anger and hurl abusive language when they're rejected. Spokespeople for Grindr, Tinder and Bumble told Business Insider they've informed users to adhere to social-distancing guidelines, but did not respond to inquiries about actions they're taking against users in places where violating lockdown orders can be against the law. Visit Business Insider's homepage for more stories . As millions remain confined to their homes to prevent the spread of coronavirus, the desire for human contact and connection has risen dramatically and led some to search for ways to break those social distancing rules. Popular dating apps — including Tinder , Bumble , and Hinge — have reported significant increases during the outbreak of swiping activity, matches between users, and messages exchanged. It's also led to the introduction of a breed of users who are interested in shirking lockdown orders, an
Canada backs U.S.-led effort for Taiwan at WHO over China’s objections
Source: www.thestar.com - Saturday, May 09, 2020
Canada approved a verbal demarche to two senior WHO executives that urged them to allow Taiwan to be admitted as an observer to an upcoming meeting because its input would be “meaningful and important.”
Rock 'n' roll pioneer Little Richard dies at age 87: Rolling Stone
Source: www.reuters.com - Saturday, May 09, 2020
Little Richard, the self-proclaimed "architect of rock 'n' roll" who built his ground-breaking sound with a boiling blend of boogie-woogie, rhythm and blues and gospel, died on Saturday at the age of 87, Rolling Stone magazine reported.
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20200402
† Denotes update to the article
Effective †Friday, April 17, 2020, CME Group will implement changes to CME ClearPort Reporting functionality. CME ClearPort Reporting supports the generation of reports based on CME ClearPort trade activity, and CME Account Management information.
These changes include:
- A new look and feel of the user interface
- Improved performance
- Streamlined search features
- New downloadable report format
- Generated reports will be exportable in Excel (csv) and Adobe (pdf) format.
These changes arecurrently available for customer testing in New Release.
Please Note: User roles and entitlements will remain unchanged.
Access ClearPort Reports from: CME Customer Center>Reports>ClearPort Reporting
Please contact the following support teams for:
- Production Environment Support:
CME Global Command Center (GCC) in the U.S. +1 800 438 8616, in Europe at +44 20 7623 4747 or in Asia at +65 6532 5010. - Application Access Support:
Enterprise Application & Systems Entitlements (EASE) in the US at +1 312 456 1560, in Europe at +44 203 379 3802 or in Asia at +1 65 6593 5536.
20200306
Effective Friday, April 3, 2020, CME Group will implement enhancements to CME ClearPort Reporting functionality. CME ClearPort Reporting supports the generation of reports based on CME ClearPort trade activity, and CME Account Management information.
The enhancements will include:
- A new look and feel of the user interface
- Improved performance
- Streamlined search features
- New downloadable report format
- Generated reports will be exportable in Excel (csv) and Adobe (pdf) format.
On Wednesday, March 18, ClearPort Reporting will be available for customer testing in New Release.
Access ClearPort Reports from: CME Customer Center>Reports>ClearPort Reporting
Please contact the following support teams for:
- Production Environment Support:
CME Global Command Center (GCC) in the U.S. +1 800 438 8616, in Europe at +44 20 7623 4747 or in Asia at +65 6532 5010. - Application Access Support:
Enterprise Application & Systems Entitlements (EASE) in the US at +1 312 456 1560, in Europe at +44 203 379 3802 or in Asia at +1 65 6593 5536.