Francisfrazier5776

As predicted PfΔGyrA clone supplemented with IPP was less sensitive to ciprofloxacin, but not the nuclear topoisomerase inhibitor etoposide. At high concentrations, however, ciprofloxacin continued to inhibit IPP-rescued PfΔGyrA possibly suggesting that ciprofloxacin may have an additional non-apicoplast target in P. falciparum. Overall, we confirm that PfGyrA is an apicoplast enzyme in the malaria parasite, essential for blood-stage parasites, and a possible target of ciprofloxacin but perhaps not the only target.Soil-Transmitted-Helminth (STH) infections are a persistent global public health problem. Control strategies for STH have been based on the use of mass drug administration (MDA) mainly targeting pre-school and school-aged-children, although there is increasing interest in expanding treatment to include adults and others through community-wide MDA. Coverage assessment is critical to understanding the real effectiveness of albendazole (ALB) treatment in those MDA programs. The work described here aims to a) evaluate the effect of type of diet (heavy or a light meal) and fasting before ALB treatment on the systemic disposition of ALB and its metabolites in treated human volunteers and, b) to evaluate the potential feasibility of detecting albendazole metabolites in urine. The data reported here demonstrate that the systemic availability of the active ALB-sulphoxide (ALBSO) metabolite was enhanced more than two-fold after food ingestion (both, a heavy or a light meal). ALB dissolution improvement related to the ingestion of food may modify the amount of drug/metabolites reaching the parasite, affecting drug efficacy and the overall success of MDA strategies. The measurement in urine samples of the amino-ALB-sulphone (NHALBSO2) derivative and ALBSO for up to 96 hours suggests that it may be feasible to develop a non-invasive tool to evaluate compliance/adherence to ALB treatment.Objective This study aimed to employ a population pharmacokinetic (PK) model to optimize the dosing regimen of voriconazole (VRC) in children with a critical illness. Methods A total of 99 children aged from 0.44 to 13.58 years old were included in this study. The stability and predictive performance of the final model were evaluated by statistical and graphical methods. The optimal dosing regimen was proposed for children with different body weight, CYP2C19 phenotype, and co-administration with omeprazole. Results The PK of VRC was described by a two-compartment model with nonlinear Michaelis-Menten elimination. Body weight, CYP2C19 phenotype, and omeprazole were significant covariates on maximum velocity of elimination (Vmax), which had an estimated typical value of 18.13 mg·h-1. Bayesian estimation suggested that dose-normalized concentration and total exposure (Cmax/D, Cmin/D, AUC24/D) were significantly different between extensive metabolizers (EM) patients and poor metabolizer (PM) patients. To achieve the target concentration early, two loading doses of 9 mg·kg-1 q12h were reliable for most children, whereas three loading doses of 6-7.5 mg·kg-1 q8h were warranted for young children weighted ≤18kg (except PM patients). The maintenance doses decreased about 30-40% in PM patients than that in EM patients. For children aged less then 2 years in EM, the maintenance dose could be as high as 9 mg·kg-1. The maintenance dose of VRC was supposed to decrease slightly when co-administration with omeprazole. Conclusion A population PK model of intravenous VRC for critically ill children has been successful developed. It is necessary to adjust dosing regimens according to CYP2C19 genotype. The optimal dosing regimens have been recommended basing on the final model.Dengue fever, caused by dengue virus (DENV) is the most prevalent arthropod-borne viral disease, and is endemic in many tropical and sub-tropical parts of the world with an increasing incidence in temperate regions. The closely related flavivirus Zika virus (ZIKV) can be transmitted vertically in utero and causes congenital Zika syndrome and other birth defects. In adults, ZIKV is associated with Guillain-Barré syndrome. There are no approved antiviral therapies against neither viruses. Effective antiviral compounds are urgently needed. Amaryllidaceae alkaloids (AAs) are a specific class of nitrogen-containing compounds produced by plants of the Amaryllidaceae family with numerous biological activities. Recently, the AA lycorine was shown to present strong antiflaviviral properties. Previously, we demonstrated that Crinum jagus contained lycorine and several alkaloids of cherylline, crinine and galanthamine-types with unknown antiviral potential. In this study, we explored their biological activities. We show that C. jagus crude alkaloid extract inhibited DENV infection. Among the purified AAs, cherylline inhibited efficiently both DENV (EC50=8.8 μM) and ZIKV replication (EC50=20.3 μM), but had no effect on HIV-1 infection. Time-of-drug-addition and -removal experiments identified a post-entry step as the one targeted by cherylline. Consistently, using subgenomic replicons and replication-defective genomes, we demonstrate that cherylline specifically hinders the viral RNA-synthesis step but not viral translation. In conclusion, AAs are an underestimated source of antiflavivirus compounds, including the effective inhibitor cherylline that could be optimized for new therapeutic approaches.Venezuelan equine encephalitis virus (VEEV) is a re-emerging alphavirus that can cause encephalitis resulting in severe human morbidity and mortality. Using a high-throughput cell-based screen, we identified a quinolinone compound that protected against VEEV-induced cytopathic effects. Analysis of viral replication in cells identified several quinolinone compounds with potent inhibitory activity against vaccine and virulent strains of VEEV. These quinolinones also displayed inhibitory activity against additional alphaviruses such as Mayaro virus and Ross River virus, although the potency was greatly reduced. Time of addition studies indicated that these compounds inhibit the early-to-mid stage of viral replication. Deep sequencing and reverse genetics studies identified two unique resistance mutations in the nsP2 gene (Y102S/C; stalk domain) that endowed VEEV resistance to this chemical series. Moreover, introduction of a K102Y mutation into the nsP2 gene enhanced the sensitivity of CHIKV to this chemical series. Computational modeling of CHIKV and VEEV nsP2 identified a highly probable docking alignment for the quinolinone compounds that require a tyrosine residue at position 102 within the helicase stalk domain. These studies identified a class of compounds with antiviral activity against VEEV and other alphaviruses, and provide further evidence that therapeutics targeting nsP2 may be useful against alphavirus infection.To combat the looming crisis of antimicrobial-resistant infections, there is an urgent need for novel antimicrobial discovery and drug target identification. The benzoxaborole series was previously identified as an inhibitor of mycobacterial growth. Here, we demonstrate that a benzoxaborole is also active against the Gram-negative bacterium Escherichia coli in vitro. We isolated resistant mutants of E. coli and subjected them to whole genome sequencing. We found mutations in the enoyl acyl carrier protein FabI. Mutations mapped around the active center site located close to the co-factor binding site. This site partially overlaps with the binding pocket of triclosan, a known FabI inhibitor. Similar to triclosan, the physical interaction of the benzoxaborole with FabI was dependent on the co-factor NAD+. Identification of the putative target of this compound in E. coli provides scope for further development and optimization of this series for Gram-negative pathogens.Objectives Antifungal stewardship (AFS) is recommended to reduce the inappropriate use of antifungal drugs. In this study, the role of AFS in providing appropriate antifungal therapy was evaluated. Methods This study included three periods as observation, feedback/education, and daily AFS activities. In observation period, the use of systemic antifungals was evaluated for a baseline measurement of appropriateness. In second period, monthly meetings were organized to provide feedback and education to physicians regarding antifungal therapy and the rate of adherence to the clinical guidelines. In final period, a clinical pharmacist participated in daily ward rounds to evaluate appropriateness of the antifungal therapy. A scoring system for appropriateness was used for comparison between the three periods. Results Four hundred and eighteen episodes of antifungal therapy were evaluated. Baseline demographics of patients were similar in all three periods for age, gender, and the number of comorbidities. The indications for antifungal use were for prophylaxis in 22.7%, Candida infections in 58.6%, and invasive mould infections in 18.7%. During the third period, 157 (78.9%) recommendations were made and 151 (96.2%) were accepted. The overall appropriateness of antifungal use increased significantly for prophylaxis (30.8%, 17.9%, 46.3%, p=0.046) and treatment of fungal diseases (27.8%, 32.4%, 71.9%, p less then 0.001) between the first, second and third periods, respectively. A 30-day mortality was not significantly changed between the three periods (19%, 15.6% and 27.5%; p=0.050). Conclusions Appropriateness in antifungal therapy can be augmented by the integration of an AFS program. A team-based evaluation of fungal infections and assessment of patients by a clinical pharmacist with a therapeutic perspective may help to increase the quality of antifungal therapy.Zika virus (ZIKV) is a mosquito-borne pathogen responsible for neurological disorders (Guillain-Barré syndrome) and congenital malformations (microcephaly). Its ability to cause explosive epidemics, such as that of 2015-16, urges the identification for effective antiviral drugs. Viral polymerase inhibitors constitute one of the most successful fields in antiviral research. Accordingly, the RNA-dependent RNA polymerase activity of flavivirus NS5 protein provides a unique target for the development of direct antivirals with high specificity and low toxicity. Here we describe the discovery and characterization of two novel non-nucleoside inhibitors of ZIKV polymerase. These inhibitors, TCMDC-143406 (6) and TCMDC-143215 (15), were identified through the screening of an open resource library of anti-kinetoplastid compounds using a fluorescence-based polymerization assay based on ZIKV NS5. The two compounds inhibited ZIKV NS5 polymerase activity in vitro and ZIKV multiplication in cell culture (EC50 values of 0.5 and 2.6 μM for 6 and 15, respectively). Both compounds also inhibited the replication of other pathogenic flaviviruses, namely West Nile virus (WNV; EC50 values of 4.3 and 4.6 μM for 6 and 15, respectively) and dengue virus 2 (DENV-2; EC50 values of 3.4 and 9.6 μM for 6 and 15, respectively). Enzymatic assays confirmed that the polymerase inhibition was produced by a non-competitive mechanism. Combinatorial assays revealed an antagonistic effect between both compounds, suggesting that they would bind to the same region of ZIKV polymerase. TAK-715 in vivo The non-nucleoside inhibitors of ZIKV polymerase here described could constitute promising lead compounds for the development of anti-ZIKV therapies and eventually broad-spectrum anti-flavivirus drugs.