Cameroon’s apparent stability is deceptive: even if it overcomes its near-term challenges, longer-term deterioration could lead to conflict.

Dans de nombreux pays, le pétrole suscite des débats controversés sur son rôle de moteur de changements économiques, sociaux et géopolitiques. Depuis quelques années, les réflexions sur la question du pétrole ont démontré une corrélation négative entre son exploitation, le développement socioéconomique, la gouvernance et le regain des conflits dans les pays producteurs.

In numerous countries, the exploitation of oil has generated debate about its economic, social and geopolitical consequences.

The UN's release of a long awaited report on crimes committed in the Democratic Republic of Congo between 1993-2003 is not only an opportunity to re-examine the historical record of mass violence in DRC -- the scale and nature of which was often overlooked in the wake of the genocide in neighboring Rwanda -- but is also a chance to correct the terms of the deceptive and fragile peace some leaders wish to proclaim in the resource-rich Great Lakes region of Africa.

Los conflictos en los países pequeños suelen agravarse debido a la indiferencia internacional. Sin embargo, en el caso de la República Centroafricana (RCA), el problema es ligeramente distinto. Hay una importante presencia internacional en este Estado, pero los actores principales han decidido mantenerse al margen y esperar en vez de intervenir activamente en la crisis.

Ahead of Chad’s presidential election on 10 April popular discontent is rising amid a major economic crisis, growing intra-religious tensions and deadly Boko Haram attacks. The regime that portrays itself as spearheading the fight against regional jihadism could see all sorts of violent actors gain influence at home if it pursues exclusionary politics and denies its people a viable social contract.

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.

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.

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.

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.

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., bla_PAO and bla_OXA-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.

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 (MIC_50/90, 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.

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.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lies behind the ongoing outbreak of coronavirus disease 2019 (COVID-19). There is a growing understanding of SARS-CoV-2 in the virology, epidemiology and clinical management strategies. However, no anti-SARS-CoV-2 drug or vaccine has been officially approved due to the absence of adequate evidence. Scientists are racing towards the development of treatment for COVID-19. Recent studies have revealed many attractive threptic options, even if some of them remain to be further confirmed in rigorous preclinical models and clinical trials. In this minireview, we aim to summarize the updated potential approaches against SARS-CoV-2. We emphasize that further efforts are warranted to develop the safest and most effective approach.

QPX7728 is an ultra-broad-spectrum boronic acid beta-lactamase inhibitor with potent inhibition of key serine and metallo beta-lactamases observed in biochemical assays. Microbiological studies using characterized strains were used to provide a comprehensive characterization of the spectrum of beta-lactamase inhibition by QPX7728. The MIC of multiple IV only (ceftazidime, piperacillin, cefepime, ceftolozane and meropenem) and orally bioavailable (ceftibuten, cefpodoxime, tebipenem) antibiotics alone and in combination with QPX7728 (4 μg/ml), as well as comparator agents, were determined against the panels of laboratory strains of P. aeruginosa and K. pneumoniae expressing over 55 diverse serine and metallo beta-lactamases. QPX7728 significantly enhanced the potency of antibiotics against the strains expressing Class A extended spectrum beta-lactamases (CTX-M, SHV, TEM, VEB, PER) and carbapenemases (KPC, SME, NMC-A, BKC-1), consistent with beta-lactamase inhibition demonstrated in biochemical assays. It also inhibits both plasmidic (CMY, FOX, MIR, DHA) and chromosomally encoded (P99, PDC, ADC) Class C beta-lactamases and Class D enzymes including carbapenemases such as OXA-48 from Enterobacteriaceae and OXA enzymes from Acinetobacter baumannii (OXA-23/24/72/58). QPX7728 is also a potent inhibitor of many class B metallo beta-lactamases (NDM, VIM, CcrA1, IMP, GIM but not SPM or L1). Addition of QPX7728 (4 μg/ml) reduced the MICs in a majority of strains to the level observed for the vector alone control, indicative of complete beta-lactamase inhibition. The ultra-broad-spectrum beta-lactamase inhibition profile makes QPX7728 a viable candidate for further development.

The biologic Griffithsin (GRFT) has recently emerged as a candidate to safely prevent sexually transmitted infections (STIs) including human immunodeficiency virus (HIV-1) and herpes simplex virus 2 (HSV-2). However, to date, there are few delivery platforms that are available to effectively deliver biologics to the female reproductive tract (FRT). The goal of this work was to evaluate rapid-release polyethylene oxide (PEO), polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) fibers, that incorporate GRFT, in in vitro (HIV-1 and HSV-2) and in vivo (HSV-2) infection models. GRFT loading was determined via ELISA, and the bioactivity of GRFT fibers was assessed using in vitro HIV-1 pseudovirus and HSV-2 plaque assays. Afterwards, the efficacy of GRFT fibers was assessed in a murine model of lethal HSV-2 infection. Finally, murine reproductive tracts and vaginal lavages were evaluated for histology and cytokine expression, 24 and 72 hr after fiber administration, to determine safety. All rapid-release formulations achieved high levels of GRFT incorporation and were completely efficacious against in vitro HIV-1 and HSV-2 infections. Importantly, all rapid-release GRFT fibers provided potent protection in a murine model of HSV-2 infection. Moreover, histology and cytokine levels, evaluated from collected murine reproductive tissues and vaginal lavages treated with blank fibers, showed no increased cytokine production or histological aberrations, demonstrating the preliminary safety of rapid-release GRFT fibers in vaginal tissue.

Mycobacterium abscessus lung infections remain difficult to treat. Recent studies have recognized the power of new combinations of antibiotics such as bedaquiline and imipenem although in vitro data have questioned this combination. We report that the efficacy of the bedaquiline plus imipenem treatment relies essentially on the activity of bedaquiline in a C3HeB/FeJ mice model of infection with a rough variant of M. abscessus. The addition of imipenem contributed at clearing the infection in the spleen.

Linezolid is the first synthetic oxazolidone agent to treat infections caused by Gram-positive pathogens. Infected patients with liver dysfunction (LD) are more likely to suffer from adverse reactions such as thrombocytopenia when standard-dose linezolid is used than patients with LD who didn't use linezolid. Currently, pharmacokinetics data of linezolid in patients with LD are limited. The study aimed to characterize pharmacokinetics parameters of linezolid in patients with LD, identify the factors influencing the pharmacokinetics, and propose an optimal dosage regimen. We conducted a prospective study and established population pharmacokinetics model with the Phoenix NLME. The final model was evaluated by goodness-of-fit plots, bootstrap analysis, and prediction corrected-visual predictive check. A total of 163 concentration samples from 45 patients with LD were adequately described by a one-compartment model with first-order elimination along with prothrombin activity (PTA) and creatinine clearance as significant covariates. Linezolid clearance (CL) was 2.68 L/h (95% confidence interval [CI]: 2.34-3.03 L/h); the volume of distribution (Vd) was 58.34 L (95% CI: 48.00-68.68 L). Model-based simulation indicated that the conventional dose was at risk for overexposure in patients with LD or severe renal dysfunction; reduced dosage (300 mg/12 h) would be appropriate to achieve safe (C_min, ss at 2-8 ug/mL) and effective targets (the ratio of AUC_0-24 at steady state to MIC, 80-100). In addition, for patients with severe LD (PTA <= 20%), the dosage (400 mg/24 h) was sufficient at an MIC <= 2 ug/mL. This study recommended therapeutic drug monitoring for patients with LD.

Recent studies highlight the abundance of commensal coagulase-negative staphylococci (CoNS) on healthy skin. Evidence suggests that CoNS actively shape the skin immunological and microbial milieu to resist colonization or infection by opportunistic pathogens, including methicillin resistant Staphylococcus aureus (MRSA), in a variety of mechanisms collectively termed colonization resistance. One potential colonization resistance mechanism is the application of quorum sensing, also called the Accessory Gene Regulator (agr) system, which is ubiquitous among staphylococci. Common and rare CoNS make autoinducing peptides (AIPs) that function as MRSA agr inhibitors, protecting the host from invasive infection. In a screen of CoNS spent media we found that Staphylococcus simulans, a rare human skin colonizer and frequent livestock colonizer, released potent inhibitors of all classes of MRSA agr signaling. We identified three S. simulans agr classes, and have shown intraspecies cross-talk between non-cognate S. simulans agr types for the first time. The S. simulans AIP-I structure was confirmed, and the novel AIP-II and AIP-III structures were solved via mass spectrometry. Synthetic S. simulans AIPs inhibited MRSA agr signaling with nanomolar potency. S. simulans in competition with MRSA reduced dermonecrotic and epicutaneous skin injury in murine models. Addition of synthetic AIP-I also effectively reduced MRSA dermonecrosis and epicutaneous skin injury in murine models. These results demonstrate potent anti-MRSA quorum sensing inhibition by a rare human skin commensal, and suggest that cross-talk between CoNS and MRSA may be important in maintaining healthy skin homeostasis and preventing MRSA skin damage during colonization or acute infection.

In vitro and in vivo interactions of minocycline and azoles including itraconazole, voriconazole, and posaconazole against filamentous pathogenic fungi were investigated. A total of 56 clinical isolates were studied in vitro via broth microdilution checkerboard technique, including 20 strains of Aspergillus fumigatus, 7 strains of A. flavus, 16 strains of Exophiala dermatitidis, 10 strains of Fusarium solani and 3 strain s of F. oxysporum. The results revealed that minocycline individually did not exhibit any significant antifungal activity against all tested strains. However, favorable synergy of minocycline with itraconazole, voriconazole, or posaconazole were observed against 34 (61%), 28 (50%), and 38 (69%) isolates, respectively, including azole resistant A. fumigatus and Fusarium spp. with inherently high MICs of azoles. Synergistic combinations resulted in 4 fold to 16-fold reduction of effective MICs of minocycline and azoles. No antagonism was observed. In vivo effect of minocycline-azole combinations were evaluated by survival assay in Galleria mellonella model infected with E. dermatitidis strain BMU00034, F. solani strain FS9, A. fumigatus strain AF293, AFR1 and AFR2 . Minocycline acted synergistically with azoles and significantly increased larvae survival in all isolates (P<0.001), including azole resistant A. fumigatus and azole-inactive Fusarium spp.. In conclusion, the results suggested that minocycline combined with azoles may help to enhance the antifungal susceptibilities of azoles against pathogenic fungi and had the potential to overcome azole resistance issues.

Brain infections with Cryptococcus neoformans are associated with significant morbidity and mortality. Cryptococcosis typically presents as meningoencephalitis or fungal mass lesions called cryptococcomas. Despite frequent in vitro discoveries of promising novel antifungals, the clinical need for drugs that can more efficiently treat these brain infections remains. A crucial step in drug development is the evaluation of in vivo drug efficacy in animal models. This mainly relies on survival studies or post-mortem analyses in large groups of animals, but these techniques only provide information on specific organs of interest at predefined time points. In this proof-of-concept study, we validated the use of non-invasive preclinical imaging to obtain longitudinal information on the therapeutic efficacy of amphotericin B or fluconazole monotherapy in meningoencephalitis and cryptococcoma mouse models. Bioluminescence imaging (BLI) enabled the rapid in vitro and in vivo evaluation of drug efficacy while complementary high-resolution anatomical information obtained by magnetic resonance imaging (MRI) of the brain allowed a precise assessment of the extent of infection and lesion growth rates. We demonstrated a good correlation between both imaging readouts and the fungal burden in various organs. Moreover, we identified potential pitfalls associated with the interpretation of therapeutic efficacy based solely on post-mortem studies, demonstrating the added value of this non-invasive dual imaging approach compared to standard mortality curves or fungal load endpoints. This novel preclinical imaging platform provides insights in the dynamic aspects of the therapeutic response and facilitates a more efficient and accurate translation of promising antifungal compounds from bench to bedside.

Bunyaviruses are significant human pathogens, causing diseases ranging from hemorrhagic fevers to encephalitis. Among these viruses, La Crosse virus (LACV), a member of the California serogroup, circulates in the eastern and midwestern United States. While LACV infection is often asymptomatic, dozens of cases of encephalitis are reported yearly. Unfortunately, no antivirals have been approved to treat LACV infection. Here, we developed a method to rapidly test potential antivirals against LACV infection. From this screen, we identified several potential antiviral molecules, including known antivirals. Additionally, we identified many novel antivirals that exhibited antiviral activity without affecting cellular viability. Valinomycin, a potassium ionophore, was among our top targets. We found that valinomycin exhibited potent anti-LACV activity in multiple cell types in a dose-dependent manner. Valinomycin did not affect particle stability or infectivity, suggesting that it may preclude virus replication by altering cellular potassium ions, a known determinant of LACV entry. We extended these results to other ionophores and found that the antiviral activity of valinomycin extended to other viral families including bunyaviruses (Rift Valley fever virus, Keystone virus), enteroviruses (Coxsackievirus, rhinovirus), flavirivuses (Zika), and coronaviruses (HCoV-229E and MERS-CoV). In all viral infections, we observed significant reductions in virus titer in valinomycin-treated cells. In sum, we demonstrate the importance of potassium ions to virus infection, suggesting a potential therapeutic target to disrupt virus replication.

Importance No antivirals are approved for the treatment of bunyavirus infection. The ability to rapidly screen compounds and identify novel antivirals is one means to accelerate drug discovery for viruses with no approved treatments. We used this approach to screen hundreds of compounds against La Crosse virus, an emerging bunyavirus that causes significant disease, including encephalitis. We identified several known and previously unidentified antivirals. We focused on a potassium ionophore, valinomycin, due to its promising in vitro antiviral activity. We demonstrate that valinomycin, as well as a selection of other ionophores, exhibits activity against La Crosse virus as well as several other distantly related bunyaviruses. We finally observe that valinomycin has activity against a wide array of human viral pathogens, suggesting that disrupting potassium ion homeostasis with valinomycin may be a potent host pathway to target to quell virus infection.

The rapid evolution of resistance in the malaria parasite to every single drug developed against it calls for the urgent identification of new molecular targets. Using a stain specific for the detection of intracellular amyloid deposits in live cells we have detected the presence of abundant protein aggregates in Plasmodium falciparum blood stages and female gametes cultured in vitro, in the blood stages of mice infected by Plasmodium yoelii, and in the mosquito stages of the murine malaria species Plasmodium berghei. Aggregated proteins could not be detected in early rings, the parasite form that starts the intraerythrocytic cycle. A proteomics approach was followed to pinpoint actual aggregating polypeptides in functional P. falciparum blood stages, which resulted in the identification of 369 proteins, with roles particularly enriched in nuclear import-related processes. Five aggregation-prone short peptides selected from this protein pool exhibited different aggregation propensity according to Thioflavin-T fluorescence measurements, and were observed to form amorphous aggregates and amyloid fibrils in transmission electron microscope images. The results presented suggest that generalized protein aggregation might have a functional role in malaria parasites. Future antimalarial strategies based on the upsetting of the pathogen's proteostasis and therefore affecting multiple gene products could represent the entry to new therapeutic approaches.

Omadacycline is a novel aminomethylcycline with activity against Gram-positive and -negative organisms, including Haemophilus influenzae, which is one of the leading causes of community-acquired bacterial pneumonia (CABP). The evaluation of antimicrobial agents against H. influenzae using standard murine infection models is challenging due to the low pathogenicity of this species in mice. Therefore, 24-hour dose-ranging studies using a one-compartment in vitro infection model were undertaken with the goal of characterizing the magnitude of the ratio of the area under the concentration-time curve (AUC) to the MIC (AUC/MIC ratio) associated with efficacy for a panel of five clinical H. influenzae isolates. These five isolates, which had MIC values of 1 or 2 mg/L, were exposed to omadacycline total-drug epithelial lining fluid (ELF) concentration-time profiles based on those observed in healthy volunteers following intravenous omadacycline administration. Relationships between change in log₁₀ colony forming units (CFU) from baseline at 24 hours and total-drug ELF AUC/MIC ratio for each isolate and the isolates pooled together were evaluated using Hill-type models and non-linear least squares regression. As evidenced by the high coefficient of determination (r²) of 0.88 to 0.98, total-drug ELF AUC/MIC ratio described the data well for each isolate and the isolates pooled together. The median total-drug ELF AUC/MIC ratio associated with net bacterial stasis and 1- and 2-log₁₀ CFU/mL reductions from baseline at 24 hours was 6.91, 8.91, and 11.1, respectively. These data were useful to support the omadacycline dosing regimens selected for the treatment of patients with CABP, as well as susceptibility breakpoints for H. influenzae.

Attention has been paid to H5N6 highly pathogenic avian influenza virus (HPAIV) because of its heavy burden on the poultry industry and human mortality. Since an influenza A virus carrying N6 neuraminidase (NA) has never spread in humans, the potential for H5N6 HPAIV to cause disease in humans and the efficacy of antiviral drugs against the virus need to be urgently assessed. We used non-human primates to elucidate the pathogenesis of H5N6 HPAIV as well as to determine the efficacy of antiviral drugs against the virus. H5N6 HPAIV infection led to high fever in cynomolgus macaques. The lung injury caused by the virus was severe with diffuse alveolar damage and neutrophil infiltration. In addition, an increase in IFN-α showed an inverse correlation with virus titers during the infection process. Oseltamivir was effective for reducing H5N6 HPAIV propagation, and continuous treatment with peramivir reduced virus propagation and severity of symptoms in the early stage. This study also showed the pathologically severe lung injury states in the cynomolgus macaques infected with H5N6 HPAIV, even in those that received early antiviral drug treatments, indicating the need for close monitoring and the need for further studies on the virus pathogenicity and new antiviral therapies.

Seasonal and pandemic influenza causes 650,000 deaths annually in the world. The emergence of drug-resistance to specific anti-influenza drugs such as oseltamivir and baloxavir marboxil highlights the urgency of novel anti-influenza chemical entity discovery. In this study, we report a series of novel thiazolides derived from an FDA-approved drug nitazoxanide with antiviral activity against influenza and a broad range of viruses. The preferred candidates 4a and 4d showed significantly enhanced anti-influenza potentials with 10-fold improvement, compared with nitazoxanide, and were effective against a variety of influenza subtypes including oseltamivir-resistant strains. Notably, the combination using of compounds 4a/4d and oseltamivir carboxylate or zanamivir displayed synergistic antiviral effect against oseltamivir-resistant strain. Mode of action analysis demonstrated that compounds 4a/4d acted at the late phase of viral infection cycle through inhibiting viral RNA transcription and replication. Further experiments showed that treatment with compounds 4a/4d significantly inhibited influenza virus infection in human lung organoids, suggesting the druggability of the novel thiazolides. In-depth transcriptome analysis revealed a series of up-regulated cellular genes that may contribute to the antiviral activities of 4a/4d. Together, our study pointed the optimization direction of nitazoxanide as anti-influenza drug, and discovered two novel-structured candidates 4a/4d with relatively broad-spectrum antiviral potential.

Many transferable quinolone-resistance mechanisms have been already identified in Gram-negative bacteria. The plasmid-encoded 65 amino-acid long ciprofloxacin-modifying enzyme, namely CrpP, was recently identified in Pseudomonas aeruginosa. We analyzed a collection of 100 clonally-unrelated and multidrug-resistant P. aeruginosa clinical isolates among which 46 (46%) were found positive for crpP-like genes, encoding five CrpP variants conferring variable levels of reduced susceptibility to fluoroquinolones. Those crpP-like genes were chromosomally located, as part of PAGI-like pathogenicity genomic islands.

Despite the worldwide re-emergence of the chikungunya virus (CHIKV) and the high morbidity associated with CHIKV infections, there is no approved vaccine or antiviral treatment available. We here aim to identify the target of a novel class of CHIKV inhibitors i.e. CHVB series. CHVB compounds inhibit the in vitro replication of CHIKV isolates with 50% effective concentrations in the low micromolar range. A CHVB-resistant variant (CHVB^res) was selected that carried two mutations in the gene encoding nsP1 (responsible for viral RNA capping), one mutation in nsP2 and one mutation in nsP3. Reverse genetics studies demonstrated that both nsP1 mutations were necessary and sufficient to achieve ~18-fold resistance, suggesting that CHVB targets viral mRNA capping. Interestingly, CHVB^res was cross-resistant to the previously described CHIKV capping inhibitors from the MADTP series, suggesting they share a similar mechanism of action. In enzymatic assays, CHVB inhibited the methyltransferase and guanylyltransferase activities of alphavirus nsP1 proteins. To conclude, we identified a class of CHIKV inhibitors that targets the viral capping machinery. The potent anti-CHIKV activity makes this chemical scaffold a potential candidate for CHIKV drug development.

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.

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.

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.

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.

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.

Earlier genetic and inhibitor studies have shown that epigenetic regulation of gene expression is critical for malaria parasite survival in multiple life stages and a promising target for new anti-malarials. We therefore evaluated the activity of 350 diverse epigenetic inhibitors against multiple stages of Plasmodium falciparum. We observed ≥90% inhibition at 10 μM for 28% of compounds against asexual blood stages and early gametocytes, of which a third retained ≥90% inhibition at 1 μM.

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.

The password-fatigued masses will be pleased to find Keeper's new 30 percent off deal, which brings it down to $20.99 per year from its typical $29.99.

On Tuesday, Avast responded to a PCMag-Motherboard investigation into the company's browser history collection practices, saying it was entirely legal. Avast users should expect to see a prompt from the antivirus products, asking them to consent to the data harvesting.

In number 10 in our countdown, I tried to offer a few thoughts to funders as they embraced new agendas and looked to avoid repeating yesterday's missteps.

BACKGROUND AND OBJECTIVES:

Children with medical complexity (CMC) comprise only 6% of the pediatric population, account for ~40% of pediatric health care spending, and provide an important opportunity for cost saving. Savings in this group can have an important impact on pediatric health care costs. The objective of this study was to assess the impact of a multicenter care management program on spending and use in CMC.

BACKGROUND:

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly with a mortality of ~27%. The Congenital Diaphragmatic Hernia Study Group (CDHSG) developed a simple postnatal clinical prediction rule to predict mortality in newborns with CDH. Our aim for this study is to externally validate the CDHSG rule in the European population and to improve its prediction of mortality by adding prenatal variables.

BACKGROUND AND OBJECTIVES:

Children born very preterm (VPT) are at high risk of cognitive impairment that impacts their educational and social opportunities. This study examined the predictive accuracy of assessments at 2, 4, 6, and 9 years in identifying preterm children with cognitive impairment by 12 years.

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