co Thioridazine is an efflux pump inhibitor in Mycobacterium avium complex but of limited clinical relevance [Susceptibility] By aac.asm.org Published On :: 2020-04-20T08:36:46-07:00 Treatment of Mycobacterium avium complex pulmonary disease (MAC-PD) is challenging partly due to high efflux pump expression. Thioridazine might block these efflux pumps. We explore thioridazine's efficacy against M. avium using minimum inhibitory concentrations (MICs), time-kill combination assays, ex vivo macrophage infection assays and efflux assays. Thioridazine is bactericidal against M. avium, inhibits intracellular growth at 2x MIC and blocks ethidium bromide efflux. However, its toxicity and low plasma concentrations, make it unlikely to add efficacy to MAC-PD therapy. Full Article
co The Emerging Role of {beta}-lactams in the Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infections [Minireviews] By aac.asm.org Published On :: 2020-04-20T08:36:46-07:00 Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) are associated with substantial morbidity and mortality. Monotherapy with first-line antimicrobials such as vancomycin (VAN; glycopeptide) and daptomycin (DAP; lipopeptide) are inadequate in some cases due to reduced antibiotic susceptibilities or therapeutic failure. In recent years, β-lactam antibiotics have emerged as a potential option for combination therapy with VAN/DAP that may meet an unmet therapeutic need for MRSA BSI. Ceftaroline (CPT), the only commercially available β-lactam in the United States with intrinsic in vitro activity against MRSA, has been increasingly studied in the setting of VAN and DAP failures. Novel combinations of first-line agents (VAN and DAP) with β-lactams have been the subject of many recent investigations due to in vitro findings such as the "see-saw effect", where β-lactam susceptibility may be improved in the presence of decreased glycopeptide and lipopeptide susceptibility. The combination of CPT and DAP, in particular, has become the focus of many scientific evaluations, due to intrinsic anti-MRSA activities and potent in vitro synergistic activity against various MRSA strains. This article reviews the available literature describing these innovative therapeutic approaches for MRSA BSI, focusing on preclinical and clinical studies, and evaluates the potential benefits and limitations of each strategy. Full Article
co Genetic Mutations Associated with Isoniazid Resistance in Mycobacterium tuberculosis in Mongolia [Epidemiology and Surveillance] By aac.asm.org Published On :: 2020-04-20T08:36:47-07:00 Globally, mutations in the katG gene account for the majority of isoniazid-resistant strains of Mycobacterium tuberculosis. Buyankhishig et al analyzed a limited number of Mycobacterium tuberculosis strains in Mongolia and found that isoniazid resistance was mainly attributable to inhA mutations. The GenoType® MTBDRplus assay was performed for isolates collected in the First National Tuberculosis Prevalence Survey and the Third Anti-Tuberculosis Drug Resistance Survey to investigate genetic mutations associated with isoniazid resistance in Mycobacterium tuberculosis in Mongolia. Of the 409 isoniazid-resistant isolates detected by the GenoType® MTBDRplus assay, 127 (31.1%) were resistant to rifampicin, 294 (71.9%) had inhA mutations without katG mutations, 113 (27.6%) had katG mutations without inhA mutations, and two (0.5%) strains had mutations in both the inhA and katG genes. Of the 115 strains with any katG mutation, 114 (99.1%) had mutations in codon 315 (S315T). Of the 296 trains with any inhA mutation, 290 (98.0%) had a C–15T mutation. The proportion of isoniazid-resistant strains with katG mutations was 25.3% among new cases and 36.2% among retreatment cases (p=0.03), as well as 17.0% among rifampicin-susceptible strains and 52.8% among rifampicin-resistant strains (p<0.01). Rifampicin resistance was significantly associated with the katG mutation (adjusted odds ratio 5.36, 95% CI 3.3–8.67, p<0.001). Mutations in inhA predominated in isoniazid-resistant tuberculosis in Mongolia. However, the proportion of katG mutations in isolates from previously treated cases was higher than that among new cases, and that in cases with rifampicin resistance was higher than that in cases without rifampicin resistance. Full Article
co Nafamostat mesylate blocks activation of SARS-CoV-2: New treatment option for COVID-19 [Letters] By aac.asm.org Published On :: 2020-04-20T08:36:47-07:00 The currently unfolding coronavirus pandemic threatens health systems and economies worldwide.... Full Article
co Cardiovascular safety and population pharmacokinetic properties of piperaquine in African patients with uncomplicated falciparum malaria - a pooled multicentre analysis [Clinical Therapeutics] By aac.asm.org Published On :: 2020-04-20T08:36:47-07:00 Dihydroartemisinin-piperaquine has shown excellent efficacy and tolerability in malaria treatment. However, concerns have been raised of potentially harmful cardiotoxic effects associated with piperaquine. The population pharmacokinetics and cardiac effects of piperaquine were evaluated in 1,000 patients, mostly children enrolled in a multicentre trial from 10 sites in Africa. A linear relationship described the QTc-prolonging effect of piperaquine, estimating a 5.90ms mean QTc-prolongation per 100ng/mL increase in piperaquine concentration. The effect of piperaquine on absolute QTc-interval estimated a mean maximum QTc-interval of 456ms (EC50=209ng/mL). Simulations from the pharmacokinetic-pharmacodynamic models predicted 1.98-2.46% risk of having QTc-prolongation > 60ms in all treatment settings. Although piperaquine administration resulted in QTc-prolongation, no cardiovascular adverse events were found in these patients. Thus, the use of dihydroartemisinin-piperaquine should not be limited by this concern. Full Article
co Species Distribution and Comparison between EUCAST and Gradient Concentration Strips Methods for Antifungal Susceptibility Testing of 112 Aspergillus Section Nigri Isolates [Susceptibility] By aac.asm.org Published On :: 2020-04-20T08:36:46-07:00 Aspergillus niger, the third species responsible for invasive aspergillosis has been considered as a homogeneous species until DNA-based identification uncovered many cryptic species. These species have been recently reclassified into the Aspergillus section Nigri. However little is yet known among the section Nigri about the species distribution and the antifungal susceptibility pattern of each cryptic species. A total of 112 clinical isolates collected from 5 teaching hospitals in France and phenotypically identified as A. niger were analyzed. Identification to the species level was carried out by nucleotide sequence analysis. The Minimum Inhibitory Concentrations (MICs) of itraconazole, voriconazole, posaconazole, isavuconazole and amphotericin B were determined by both the EUCAST and gradient concentration strips methods. Aspergillus tubingensis (n=51, 45.5%) and A. welwitschiae (n=50, 44.6%) were the most common species while A. niger accounted for only 6.3% (n=7). The MICs of azoles drugs were higher for A. tubingensis than for A. welwitschiae. The MIC of amphotericin B was 2 mg/L or less for all isolates. Importantly, MICs determined by EUCAST showed no correlation with those determined by gradient concentration strips methods, these latter being lower than the former (Spearman's rank correlation tests ranging - depending on the antifungal agent - from 0.01 to 0.25; p>0.4). In conclusion, A. niger should be considered as a minority species in the section Nigri. The differences in MICs between species for different azoles underline the importance of accurate identification. Significant divergences in the determination of MIC between EUCAST and gradient concentration strips methods require further investigation. Full Article
co Concurrent local delivery of diflunisal limits bone destruction but fails to improve systemic vancomycin efficacy during Staphylococcus aureus osteomyelitis [Clinical Therapeutics] By aac.asm.org Published On :: 2020-04-27T08:14:57-07:00 Staphylococcus aureus osteomyelitis is a debilitating infection of bone. Treatment of osteomyelitis is impaired by the propensity of invading bacteria to induce pathologic bone remodeling that may limit antibiotic penetration to the infectious focus. The nonsteroidal anti-inflammatory drug diflunisal was previously identified as an osteoprotective adjunctive therapy for osteomyelitis, based on the ability of this compound to inhibit S. aureus quorum sensing and subsequent quorum-dependent toxin production. When delivered locally during experimental osteomyelitis, diflunisal significantly limits bone destruction without affecting bacterial burdens. However, because diflunisal's "quorum-quenching" activity could theoretically increase antibiotic recalcitrance, it is critically important to evaluate this adjunctive therapy in the context of standard of care antibiotics. The objective of this study is to evaluate the efficacy of vancomycin to treat osteomyelitis during local diflunisal treatment. We first determined that systemic vancomycin effectively reduces bacterial burdens in a murine model of osteomyelitis, and identified a dosing regimen that decreases bacterial burdens without eradicating infection. Using this dosing scheme, we found that vancomycin activity is unaffected by the presence of diflunisal in vitro and in vivo. Similarly, locally-delivered diflunisal still potently inhibits osteoblast cytotoxicity in vitro and bone destruction in vivo in the presence of sub-therapeutic vancomycin. However, we also found that the resorbable polyurethane foams used to deliver diflunisal serve as a nidus for infection. Taken together, these data demonstrate that diflunisal does not significantly impact standard of care antibiotic therapy for S. aureus osteomyelitis, but also highlight potential pitfalls encountered with local drug delivery. Full Article
co Anidulafungin and Micafungin concentrations in Cerebrospinal Fluid and in Cerebral Cortex [Pharmacology] By aac.asm.org Published On :: 2020-04-27T08:14:56-07:00 Anidulafungin and micafungin were quantified in cerebrospinal fluid (CSF) of critically ill adults and in cerebral cortex of deceased patients. In CSF, anidulafungin levels (<0.01-0.66 μg/ml) and micafungin levels (<0.01-0.16 μg/ml) were lower than the simultaneous plasma concentrations (0.77-5.07 μg/ml and 1.21-8.70 μg/ml, respectively). In cerebral cortex, anidulafungin and micafungin levels were 0.21-2.34 μg/g and 0.18-2.88 μg/g, respectively. Thus, MIC values of several pathogenic Candida strains exceed concentrations in CSF and in brain. Full Article
co Emergence of Mycobacterium leprae rifampicin resistance evaluated by whole-genome sequencing after 48 years of irregular treatment [Epidemiology and Surveillance] By aac.asm.org Published On :: 2020-04-27T08:14:57-07:00 A case of M. leprae rifampicin resistance after irregular anti-leprosy treatments since 1971 is reported. Whole-genome sequencing from four longitudinal samples indicated relapse due to acquired rifampicin resistance and not to reinfection with another strain. A putative compensatory mutation in rpoC was also detected. Clinical improvement was achieved using an alternative therapy. Full Article
co Effect of the Lysin, Exebacase, on Cardiac Vegetation Progression in a Rabbit Model of Methicillin-Resistant Staphylococcus aureus (MRSA) Endocarditis as Determined by Echocardiography [Pharmacology] By aac.asm.org Published On :: 2020-04-27T08:14:56-07:00 Background: MRSA pose significant therapeutic challenges, related to their: frequency in clinical infections; innate virulence properties; and propensity for multi-antibiotic resistance. MRSA are among the most common causes of endovascular infections, including infective endocarditis (IE).Objective: To employ transthoracic echocardiography (TTE) to evaluate the effect of exebacase, a novel direct lytic agent, in experimental aortic valve MRSA IE.Study Design: TTE was utilized to evaluate the in vivo effect of exebacase on MRSA-infected vegetation progression when combined with daptomycin (vs daptomycin alone). Primary intravegetation outcomes were: maximum size; weights at sacrifice; and MRSA counts at infection baseline vs after 4 days of daptomycin treatment (alone or in addition to exebacase administered once on treatment Day 1).Results: A single dose of exebacase in addition to daptomycin cleared significantly more intravegetation MRSA than daptomycin alone. This was associated with a statistical trend toward reduced maximum vegetation size in the exebacase + daptomycin vs the daptomycin-alone therapy groups (p = 0.07). Also, mean vegetation weights in the exebacase-treated group were significantly lower vs daptomycin-alone (p < 0.0001). Maximum vegetation size by TTE correlated with vegetation weight (p = 0.005). In addition, intravegetation MRSA counts in the combination group were significantly lower vs untreated controls (p<0.0001) and the daptomycin-alone group (p<0.0001).Conclusion: This study suggests that exebacase has a salutary impact on MRSA-infected vegetation progression when combined with daptomycin, especially in terms of vegetation MRSA burden, size and weight. Moreover, TTE appears to be an efficient non-invasive tool to assess therapeutic efficacies in experimental MRSA IE. Full Article
co Impact of vanA-positive Enterococcus faecium exhibiting diverse susceptibility phenotypes to glycopeptides on 30-day mortality of patients with a bloodstream infection [Epidemiology and Surveillance] By aac.asm.org Published On :: 2020-04-27T08:14:57-07:00 Introduction: This study was performed to evaluate the impacts of vanA-positivity of Enterococcus faecium (EFM) exhibiting diverse susceptibility phenotypes to glycopeptides on clinical outcomes in patients with a bloodstream infection (BSI) through a prospective, multicenter, observational study.Methods: A total of 509 patients with an EFM BSI from eight sentinel hospitals in South Korea during a two-year period were enrolled in this study. Risk factors of the hosts and causative EFM isolates were assessed to determine associations with the 30-day mortality of EFM BSI patients via multivariable logistic regression analyses.Results: The vanA gene was detected in 35.2% (179/509) of EFM isolates; 131 EFM isolates exhibited typical VanA phenotypes (group vanA-VanA), while the remaining 48 EFM isolates exhibited atypical phenotypes (group vanA-Atypical), including VanD (n = 43) and vancomycin-variable phenotypes (n = 5). A multivariable logistic regression indicated that vanA-positivity of causative pathogens was independently associated with the increased 30-day mortality rate in the patients with an EFM BSI; however, there was no significant difference in the survival rates between the patients of the vanA-VanA and vanA-Atypical groups (log-rank test, P = 0.904).Conclusions: A high 30-day mortality rate was observed in patients with vanA-positive EFM BSIs, and vanA-positivity of causative EFM was an independent risk factor for early mortality irrespective of the susceptibility phenotypes to glycopeptides; thus, intensified antimicrobial stewardship is needed to improve clinical outcome of patients with vanA-positive EFM BSI. Full Article
co Population Pharmacokinetic Analyses for Omadacycline Using Phase 1 and 3 Data [Pharmacology] By aac.asm.org Published On :: 2020-04-27T08:14:56-07:00 Omadacycline, a novel aminomethylcycline antibiotic with activity against Gram-positive and -negative organisms, including tetracycline-resistant pathogens, received FDA approval in October, 2018 for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). A previously-developed population pharmacokinetic (PK) model based on Phase 1 intravenous and oral PK data was refined using data from infected patients. Data from 10 Phase 1 studies used to develop the previous model were pooled with data from three additional Phase 1 studies, a Phase 1b uncomplicated urinary tract infection study, one Phase 3 CABP study, and two Phase 3 ABSSSI studies. The final population PK model was a three-compartment model with first-order absorption using transit compartments to account for absorption delay following oral dosing and first-order elimination. Epithelial lining fluid (ELF) concentrations were modeled as a sub-compartment of the first peripheral compartment. A food effect on oral bioavailability was included in the model. Sex was the only significant covariate identified, with 15.6% lower clearance for females relative to males. Goodness-of-fit diagnostics indicated a precise and unbiased fit to the data. The final model, which was robust in its ability to predict plasma and ELF exposures following omadacycline administration, was also able to predict the central tendency and variability in concentration-time profiles using an external Phase 3 ABSSSI dataset. A population PK model, which described omadacycline PK in healthy subjects and infected patients, was developed and subsequently used to support pharmacokinetic-pharmacodynamic (PK-PD) and PK-PD target attainment assessments. Full Article
co Combination Therapy Using Benznidazole and Aspirin During the Acute Phase of Experimental Chagas Disease Prevents Cardiovascular Dysfunction and Decreases Typical Cardiac Lesions in the Chronic Phase [Clinical Therapeutics] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Chagas disease, caused by the protozoan Trypanosoma cruzi, is one of the main causes of death due to cardiomyopathy and heart failure in Latin American countries. The treatment of Chagas disease is directed at eliminating the parasite, decreasing the probability of cardiomyopathy, and disrupting the disease transmission cycle. Benznidazole (BZ) and nifurtimox (NFX) are recognized as effective drugs for the treatment of Chagas disease by the World Health Organization, but both have high toxicity and limited efficacy, especially in the chronic disease phase. At low doses, aspirin (ASA) has been reported to protect against T. cruzi infection. We evaluated the effectiveness of BZ in combination with ASA at low doses during the acute disease phase and evaluated cardiovascular aspects and cardiac lesions in the chronic phase. ASA treatment prevented the cardiovascular dysfunction (hypertension and tachycardia) and typical cardiac lesions. Moreover, BZ+ASA-treated mice had a smaller cardiac fibrotic area than that in BZ-treated mice. These results were associated with an increase in the number of eosinophils and reticulocytes and level of nitric oxide in the plasma and cardiac tissue of ASA-treated mice relative to respective controls. These effects of ASA and BZ+ASA in chronically infected mice were inhibited by pretreatment with the LXA4 receptor antagonist, Boc-2, indicating that the protective effects of ASA are mediated by ASA-triggered lipoxin. These results emphasize the importance of exploring new drug combinations for treatments of acute phase of Chagas disease that are beneficial for chronic patients. Full Article
co The emergence of fexA in mediating resistance to florfenicols in Campylobacter [Mechanisms of Resistance] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Florfenicol belongs to a class of phenicol antimicrobials widely used as feed additives and for the treatment of respiratory infections. In recent years, increasing resistance to florfenicol has been reported in Campylobacter spp., the leading foodborne enteric pathogen causing diarrheal diseases worldwide. Here, we reported the identification of fexA, a novel mobile florfenicol resistance gene in Campylobacter. Of the 100 Campylobacter jejuni strains isolated from poultry in Zhejiang, China, nine of them were shown to be fexA positive, and their whole genome sequences were further determined by integration of Illumina short-read and MinION long-read sequencing. The fexA gene was found in the plasmid of one strain and chromosomes of eight strains, and its location was verified by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern blotting. Based on comparative analysis, the fexA gene was located within a region with the tet(L)-fexA-catA-tet(O) gene arrangement, demonstrated to be successfully transferrable among C. jejuni strains. Functional cloning indicated that acquisition of the single fexA gene significantly increased resistance to florfenicol, whereas its inactivation resulted in increased susceptibility to florfenicol in Campylobacter. Taken together, these results indicated that the emerging fexA resistance is horizontally transferable, which might greatly facilitate the adaptation of Campylobacter in food producing environments where florfenicols are frequently used. Full Article
co Optimal dose or optimal exposure? Consideration for linezolid in tuberculosis treatment [Letters] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Exploring different ways of minimising linezolid toxicity without compromising efficacy is a major quest in the treatment of drug resistant tuberculosis (TB).... Full Article
co Focusing the lens on the CAMERA concepts: Early combination {beta}-lactam and vancomycin therapy in methicillin-resistant Staphylococcus aureus bacteremia [Minireviews] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Methicillin-resistant Staphylococcus aureus (MRSA) has grown to become a major burden on healthcare systems. The cumulation of limited therapeutic options and worsened patient outcomes with persistent MRSA bacteremia has driven research in optimizing its initial management. The guidelines published by the Infectious Disease of America currently recommend combination therapy for refractory MRSA bacteremia, but the utility of combining antibiotics from the start of therapy is under investigation. The alternative strategy of early use of a β-lactam antibiotics in combination with vancomycin upon initial MRSA bacteremia detection has shown promise. While this concept has gained international attention, providers should give this strategy serious consideration prior to implementation. The objective of this review is to examine retrospective and prospective evidence for early combination with vancomycin and β-lactam antibiotics, as well as explore potential consequences of combination therapy. Full Article
co Manogepix (APX001A) displays potent in vitro activity against human pathogenic yeast, but with an unexpected correlation to fluconazole MICs [Susceptibility] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Manogepix (APX001A) is the active moiety of the novel drug candidate fosmanogepix (APX001). We previously reported the broad-spectrum activity of manogepix but also observed a correlation between increased manogepix and fluconazole MICs. Here we extended this study and included isolates with acquired fluconazole resistance.Isolates (n=835) were identified using CHROMagar, MALDI-TOF and, when needed, ITS-sequencing. EUCAST E.Def 7.3.1 susceptibility testing included manogepix, amphotericin B, anidulafungin, micafungin, fluconazole and voriconazole. Manogepix wildtype-upper-limit (WT-UL) values were established following EUCAST-principles for ECOFF setting allowing wildtype/non-wildtype classification. Drug-specific MIC correlations were investigated using Pearson's correlation.Manogepix modal MICs were low (range 0.004-0.06 mg/L against 16/20 included species). Exceptions were C. krusei and C. inconspicua, and to a lesser extent C. kefyr and Pichia kluyveri. The activity was independent of Fks echinocandin hot-spot alterations (n=17). Adopting the WT-UL established for C. albicans, C. dubliniensis, C. glabrata, C. parapsilosis and C. tropicalis, 14/724 (1.9%) isolates were non-wildtype for manogepix. Twelve of these (85.7%) were also non-wildtype for fluconazole. A statistically significant correlation was observed between manogepix and fluconazole MICs for C. albicans, C. dubliniensis, C. glabrata, C. parapsilosis and C. tropicalis (Pearson r=0.401-0.575), but not between manogepix and micafungin or amphotericin B MICs for any species except C. tropicalis (r=0.519 for manogepix versus micafungin).Broad-spectrum activity was confirmed for manogepix against contemporary yeast. However, a 1-4 two-fold-dilution increase in manogepix MICs is observed in a subset of isolates with acquired fluconazole resistance. Further studies on the potential underlying mechanism and implication for optimal dosing are warranted. Full Article
co Distribution of linezolid in tuberculosis lesions in patients with spinal multidrug-resistant tuberculosis [Pharmacology] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Linezolid has strong antimicrobial activity against the multidrug-resistant (MDR) strains of Mycobacterium tuberculosis. Little is known about the distribution of linezolid in tuberculosis (TB) lesions in patients with MDR-TB. The aim of this study is to evaluate the distribution of linezolid in TB lesions in patients with spinal MDR-TB. Nine patients with spinal MDR-TB were enrolled prospectively from August 2019 to February 2020. The patients received a linezolid-containing anti-TB treatment regimen and needed surgery for the removal of TB lesions. During the operation, nine blood samples, eight diseased bone tissue samples, seven pus samples and four granulation tissue samples were collected simultaneously and 2 h after the oral administration of 600 mg of linezolid. Linezolid concentrations in plasma, diseased bone tissue, pus, and granulation tissue samples were subjected to high-performance liquid chromatography–tandem mass spectrometry. At sample collection, the mean concentrations of linezolid in plasma, diseased bone tissue, pus, and granulation tissue samples of the nine patients were 11.14 ± 5.82, 5.94 ± 4.27, 11.09 ± 4.58, 14.08 ± 10.61 mg/L, respectively. The mean ratios of linezolid concentration in diseased bone/plasma, pus/plasma, and granulation/plasma were 53.84%, 91.69%, and 103.57%, respectively. The mean ratios of linezolid concentration in pus/plasma and granulation/plasma were higher than those in diseased bone/plasma, and the difference was statistically significant (t =-2.810, p = 0.015; t =-4.901, p = 0.001). In conclusion, linezolid had different concentration distributions in different types of TB infected tissues in patients with spinal MDR-TB. Full Article
co Clinically relevant epithelial lining fluid concentrations of meropenem with ciprofloxacin provide synergistic killing and resistance suppression of hypermutable Pseudomonas aeruginosa in a dynamic biofilm model [Pharmacology] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Treatment of exacerbations of chronic Pseudomonas aeruginosa infections in patients with cystic fibrosis (CF) is highly challenging due to hypermutability, biofilm formation and an increased risk of resistance emergence. We evaluated the impact of ciprofloxacin and meropenem as monotherapy and in combination in the dynamic in vitro CDC biofilm reactor (CBR). Two hypermutable P. aeruginosa strains, PAOmutS (MICciprofloxacin 0.25 mg/L, MICmeropenem 2 mg/L) and CW44 (MICciprofloxacin 0.5 mg/L, MICmeropenem 4 mg/L), were investigated for 120h. Concentration-time profiles achievable in epithelial lining fluid (ELF) following FDA-approved doses were simulated in the CBR. Treatments were ciprofloxacin 0.4g every 8h as 1h-infusions (80% ELF penetration), meropenem 6 g/day as continuous infusion (CI; 30% and 60% ELF penetration) and their combinations. Counts of total and less-susceptible planktonic and biofilm bacteria and MICs were determined. Antibiotic concentrations were quantified by UHPLC-PDA. For both strains, all monotherapies failed with substantial regrowth and resistance of planktonic (≥8log10 CFU/mL) and biofilm (>8log10 CFU/cm2) bacteria at 120h (MICciprofloxacin up to 8 mg/L, MICmeropenem up to 64 mg/L). Both combination treatments demonstrated synergistic bacterial killing of planktonic and biofilm bacteria of both strains from ~48h onwards and suppressed regrowth to ≤4log10 CFU/mL and ≤6log10 CFU/cm2 at 120h. Overall, both combination treatments suppressed amplification of resistance of planktonic bacteria for both strains, and biofilm bacteria for CW44. The combination with meropenem at 60% ELF penetration also suppressed amplification of resistance of biofilm bacteria for PAOmutS. Thus, combination treatment demonstrated synergistic bacterial killing and resistance suppression against difficult-to-treat hypermutable P. aeruginosa strains. Full Article
co Quercetin blocks Ebola Virus infection by counteracting the VP24 Interferon inhibitory function [Antiviral Agents] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Ebola Virus (EBOV) is among the most devastating pathogens causing fatal hemorrhagic fever in humans. The 2013–2016 epidemics resulted in over 11000 deaths, while another outbreak is currently ongoing. Since there is no FDA-approved drug so far to fight EBOV infection, there is an urgent need to focus on drug discovery. Considering the tight correlation between the high EBOV virulence and its ability to suppress the type-I Interferon (IFN-I) system, identifying molecules targeting viral protein VP24, one of the main virulence determinants blocking IFN response, is a promising novel anti-EBOV therapy approach. Hence, in the effort of finding novel EBOV inhibitors, a screening of a small set of flavonoids was performed, showing that Quercetin and Wogonin can suppress the VP24 effect on IFN-I signaling inhibition. The mechanism of action of the most active compound, Quercetin, showing an IC50 value of 7.4 μM, was characterized to significantly restore the IFN-I signaling cascade, blocked by VP24, by directly interfering with the VP24 binding to karyopherin-α and thus restoring P-STAT1 nuclear transport and IFN genes transcription. Quercetin significantly blocked viral infection, specifically targeting EBOV VP24 anti-IFN-I function. Overall, Quercetin is the first identified inhibitor of the EBOV VP24 anti-IFN function, representing a molecule interacting with a viral binding site that is very promising for further drug development aiming to block EBOV infection at the early steps. Full Article
co Reply to Kim et al., "Optimal Dose or Optimal Exposure? Consideration for Linezolid in Tuberculosis Treatment" [Author Reply] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 We thank Kim and colleagues for their interest in our study.... Full Article
co Identification of antiviral drug candidates against SARS-CoV-2 from FDA-approved drugs [Antiviral Agents] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Drug repositioning is the only feasible option to address the COVID-19 global challenge immediately. We screened a panel of 48 FDA-approved drugs against SARS-CoV-2 which were pre-selected by an assay of SARS-CoV and identified 24 potential antiviral drug candidates against SARS-CoV-2 infection. Some drug candidates showed very low micromolar IC50s and in particular, two FDA-approved drugs - niclosamide and ciclesonide – were notable in some respects. Full Article
co Evaluation of leishmanicidal activity of an in silico screened novel inhibitor against ascorbate peroxidase of Leishmania donovani [Mechanisms of Action] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 Peroxidases are a group of heterogeneous family of enzyme that plays diverse biological functions. Ascorbate peroxidase is a redox enzyme that is reduced by trypanothione, which plays a central role in the redox defence system of Leishmania. In view of developing new and novel therapeutics, we have performed in silico studies in order to search for ligand library and identification of new drug candidates and its physiological role against promastigotes and intracellular amastigotes of Leishmania donovani. Our results demonstrated that the selected inhibitor ZINC96021026 has significant anti-leishmanial effect and effectively killed both free and intracellular forms of the parasite. ZINC96021026 was found to be identical to ML-240, a selective inhibitor of Valosin-containing protein (VCP) or p97, a member of AAA-ATPase protein family which was derived from the scaffold of DBeQ, targeting the D2-ATPase domain of the enzyme. ZINC96021026 (ML-240) thus have broad range of cellular functions, thought to be derived from its ability to unfold proteins or disassemble protein complexes besides inhibiting the ascorbate peroxidase activity. ML-240 may inhibits the parasite's ascorbate peroxidase leading to extensive apoptosis and inducing generation of reactive oxygen species. Taken together, our results demonstrated that ML-240 could be an attractive therapeutic option for treatment against leishmaniasis. Full Article
co Comparative Genomic Analysis of Third Generation Cephalosporin-Resistant Escherichia coli Harboring blaCMY-2-Positive IncI1 group, IncB/O/K/Z, and IncC Plasmids Isolated from Healthy Broilers in Japan. [Epidemiology and Surveillance] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 The off-label use of third generation cephalosporin (3GC) during in ovo vaccination or vaccination of newly hatched chicks, was a common practice worldwide. CMY-2-producing Escherichia coli have been disseminated among broiler production. The objectives of this study were to determine the epidemiological linkage of blaCMY-2-positive plasmids among broilers both within and outside Japan because grandparent stock and parent stock were imported in Japan. We examined the whole genome sequences of 132 3GC-resistant E. coli isolates collected from healthy broilers during 2002-2014. The predominant 3GC-resistance gene was blaCMY-2, which was detected in the plasmids of 87 (65.9%) isolates. The main plasmid replicon types were IncI1-I (n=21; 24.1%), IncI (n=12; 13.8%), IncB/O/K/Z (n=28; 32.2%), and IncC (n=22; 25.3%). Those plasmids were subjected to gene clustering and network analyses and plasmid multi-locus sequence typing (pMLST). The chromosomal DNA of isolates was subjected to MLST and single nucleotide variant (SNV)-based phylogenetic analysis.MLST and SNV-based phylogenetic analysis revealed high diversity of E. coli isolates. ST429 harboring blaCMY-2-positive IncB/O/K/Z was closely related to isolates from broiler in Germany harboring blaCMY-2-positive IncB/O/K/Z. pST55-IncI and pST12-IncI1-I and pST3-IncC were prevalent in western Japan. pST12-IncI1-I and pST3-IncC were closely related to those detected in E. coli isolates from chicken in American continent, whereas 26 IncB/O/K/Z were related to those in Europe. These data will be useful to reveal the whole picture of transmission of CMY-2-producing bacteria in and out of Japan. Full Article
co Comparative plasma pharmacokinetics of ceftriaxone and ertapenem between normoalbuminemia, hypoalbuminemia and with albumin replacement in a sheep model. [Pharmacology] By aac.asm.org Published On :: 2020-05-04T08:49:24-07:00 BackgroundOptimal concentrations of unbound antimicrobials are essential for maximum microbiological effect. Although hypoalbuminemia and albumin fluid resuscitation are common in critical care, the effects of different albumin concentrations on the unbound concentrations of highly protein-bound antimicrobials are not known. The aim of this study was to compare effects of different albumin states on total and unbound concentrations of ertapenem and ceftriaxone using an ovine model.MethodsDesignProspective, three phase intervention observational study.SubjectsHealthy Merino sheep.InterventionsEight sheep were subject to three experimental phases; normoalbuminemia, hypoalbuminemia using plasmapheresis and albumin replacement using a 25% albumin solution. In each phase, ceftriaxone 40 mg/kg and ertapenem 15 mg/kg were given intravenously. Blood samples were collected at pre-defined intervals and analyzed using an ultra-high-performance liquid chromatography tandem mass spectrometry method. Pharmacokinetic parameters such as area under the curve (AUC0-24), plasma clearance (CL) and apparent volume of distribution in the terminal phase (Vd) were estimated and compared between the phases.ResultsThe protein and albumin concentrations were significantly different between phases. Hypoalbuminemia resulted in a significantly lower AUC0-24 and higher CL of total and unbound concentrations of ceftriaxone compared to the other phases. Whereas albumin replacement led to higher AUC0-24 and lower CL compared to other phases for both drugs. The Vd for total drug concentrations for both drugs were significantly lower with albumin replacement.ConclusionsFor highly protein-bound drugs such as ceftriaxone and ertapenem, both hypoalbuminemia and albumin replacement may affect unbound drug exposure. Full Article
co Inhibition of SARS-CoV-2 infection by the cyclophilin inhibitor Alisporivir (Debio 025) [Antiviral Agents] By aac.asm.org Published On :: 2020-05-06T08:16:52-07:00 Cyclophilins play a key role in the lifecycle of coronaviruses. Alisporivir (Debio 025) is a non-immunosuppressive analogue of cyclosporin A with potent cyclophilin inhibition properties. Alisporivir reduced SARS-CoV-2 RNA production in a dose-dependent manner in VeroE6 cell line, with an EC50 of 0.46±0.04 μM. Alisporivir inhibited a post-entry step of the SARS-CoV-2 lifecycle. These results justify that a proof-of-concept Phase 2 trial be rapidly conducted with alisporivir in patients with SARS-CoV-2 infection. Full Article
co Feds Seize WeLeakInfo.com for Selling Access to Stolen Data By www.pcmag.com Published On :: The FBI seizes the internet domain to WeLeakInfo.com, a site that was cataloging billions of records, such as email addresses and passwords, from more than 10,300 data breaches at various companies and service providers. Full Article
co Oops! Microsoft Briefly Leaked 250M Customer Support Records By www.pcmag.com Published On :: The records involved conversation logs between Microsoft support agents and customers across the globe, dating back to 2005. Most of the records were redacted of customer contact information, but not all. Full Article
co The Cost of Avast's Free Antivirus: Companies Can Spy on Your Clicks By www.pcmag.com Published On :: Avast is harvesting users' browser histories on the pretext that the data has been 'de-identified,' thus protecting your privacy. But the data, which is being sold to third parties, can be linked back to people's real identities, exposing every click and search they've made. Full Article
co New Coronavirus Strain? Nope, Just Hackers Trying to Spread Malware By www.pcmag.com Published On :: The hackers have been using files and emails that warn about a new coronavirus strain to trick users into opening them. Doing so can secretly deliver malware to the victim's machine. Full Article
co The Best Parental Control Software for 2020 By www.pcmag.com Published On :: Parenting styles run the gamut and so do the features in parental control and monitoring utilities. We've tested the top hardware- and software-based services to help you choose the right one for your family. Full Article
co Fin24.com | JSE wrap | Oil price drop drives further stock pessimism By www.fin24.com Published On :: Tue, 21 Apr 2020 17:59:20 +0200 The JSE fell on Tuesday as global markets tumbled on the back of a rout in crude oil prices. Full Article
co Fin24.com | Brent crude oil drops to 21-year low as selling pressure intensifies By www.fin24.com Published On :: Wed, 22 Apr 2020 08:12:12 +0200 "The entire energy market is still on a knife edge," says an economist. Full Article
co Fin24.com | JSE wrap | Local stocks firmer as inflation slows By www.fin24.com Published On :: Wed, 22 Apr 2020 19:38:53 +0200 The local bourse inched higher on Wednesday as global stocks took a breather following consecutive sessions of weakness. Full Article
co Fin24.com | JSE wrap | Surge as global sentiment remains optimistic By www.fin24.com Published On :: Thu, 23 Apr 2020 19:24:14 +0200 Local stocks advanced for a second consecutive session on Thursday as global markets remained resurgent. Full Article
co Fin24.com | Oil prices roar back on US-Iran tensions By www.fin24.com Published On :: Thu, 23 Apr 2020 20:43:56 +0200 Oil prices made a spectacular comeback Thursday as fresh US-Iran tensions erupted, also helping equities advance after US labour market figures provided a glimmer of hope for the world's top economy. Full Article
co Fin24.com | Stocks struggle as antiviral drug hopes fade By www.fin24.com Published On :: Fri, 24 Apr 2020 16:55:37 +0200 Stock markets struggled on Friday as hopes of quickly finding a treatment for coronavirus were dashed, analysts said, and more crushing economic data delivered a body blow to confidence. Full Article
co Fin24.com | Stock markets rally on virus hopes, but oil tanks By www.fin24.com Published On :: Mon, 27 Apr 2020 15:31:18 +0200 Equity markets have rallied Monday as countries eased coronavirus lockdown measures, but oil prices tumbled as a supply glut offset output cuts. Full Article
co Fin24.com | Gold falls as moves to reopen economies erode appetite for havens By www.fin24.com Published On :: Tue, 28 Apr 2020 11:57:28 +0200 The precious metal eased for a third day after US equities hit the highest in almost seven weeks as states including Florida took steps toward easing restrictions. Full Article
co Fin24.com | Local bourse firms as global economies gear for partial reopening By www.fin24.com Published On :: Tue, 28 Apr 2020 17:54:10 +0200 Global markets rallied on the back of optimism that most governments were gearing up to at least partially reopen their economies following lockdowns to prevent the spread of the coronavirus. Full Article
co Fin24.com | Positive virus drug trial news spurs stocks By www.fin24.com Published On :: Wed, 29 Apr 2020 17:54:49 +0200 The surge in stocks was on the back of positive news from trials being conducted on a potential treatment for the coronavirus. With most economies looking to partially reopen their economies, this brought a jump across most asset classes including commodities. Full Article
co Fin24.com | SA stocks are on track for a record month By www.fin24.com Published On :: Thu, 30 Apr 2020 15:08:20 +0200 Unprecedented demand for online services and entertainment during the Covid-19 pandemic lockdowns, along with a scramble for haven investments, have helped set South African stocks on course for a record month. Full Article
co Fin24.com | JSE erases earlier gains as global economy exhibits more strain By www.fin24.com Published On :: Thu, 30 Apr 2020 18:14:24 +0200 The local bourse had managed to open firmer following a rally in Asian stocks in earlier trading. Full Article
co Fin24.com | Stock markets plunge on devastating growth data By www.fin24.com Published On :: Thu, 30 Apr 2020 19:16:44 +0200 Stock markets plunged on Thursday after economic growth data confirmed fears of Covid-19's bruising impact on the world economy. Full Article
co Fin24.com | Gold bars fight coronavirus kits for space on the plane By www.fin24.com Published On :: Sun, 03 May 2020 12:27:11 +0200 Swiss refiner Valcambi SA tried for five straight days last month to move a shipment of gold out of Hong Kong. Twice the metal was packed carefully onto a plane, only to be offloaded again. Full Article
co Fin24.com | Markets wrap | JSE retreats as global markets fret over economic growth By www.fin24.com Published On :: Mon, 04 May 2020 18:55:42 +0200 Deep losses were recorded across most European benchmarks except the FTSE 100 which managed to trade relatively flat on the day. Full Article
co Fin24.com | Oil rises for a fifth day with output cuts easing glut concern By www.fin24.com Published On :: Tue, 05 May 2020 09:15:12 +0200 Oil was headed for the longest run of daily gains in more than nine months on signs the worst of the supply glut may be over as production cuts start to take effect. Full Article
co Fin24.com | Markets wrap | Firmer close in Asia lifts JSE All-Share Index By www.fin24.com Published On :: Wed, 06 May 2020 19:11:14 +0200 On the currency market, the rand traded softer against the greenback as it slipped to a session low of R18.77/$. Full Article
co Fin24.com | Markets wrap | Local stocks edge higher as optimism remains By www.fin24.com Published On :: Thu, 07 May 2020 18:57:47 +0200 Still, there was disappointment in terms of economic data following the release of the SACCI Business Confidence index data for April which came in at 77.8, compared to a forecast of 89.2. Full Article
co Fin24.com | Oil set for second weekly gain with market starting to rebalance By www.fin24.com Published On :: Fri, 08 May 2020 10:08:03 +0200 Oil headed for its first back-to-back weekly gain since February as output cuts from the biggest producers and a nascent recovery in demand began to rebalance a market awash with crude. Full Article