Antimicrobial susceptibility patterns of respiratory Gram-negative bacterial isolates from COVID-19 patients in Switzerland

Background Bacterial superinfections associated with COVID-19 are common in ventilated ICU patients and impact morbidity and lethality. However, the contribution of antimicrobial resistance to the manifestation of bacterial infections in these patients has yet to be elucidated. Methods We collected 70 Gram-negative bacterial strains, isolated from the lower respiratory tract of ventilated COVID-19 patients in Zurich, Switzerland between March and May 2020. Species identification was performed using MALDI-TOF; antibiotic susceptibility profiles were determined by EUCAST disk diffusion and CLSI broth microdilution assays. Selected Pseudomonas aeruginosa isolates were analyzed by whole-genome sequencing. Results Pseudomonas aeruginosa (46%) and Enterobacterales (36%) comprised the two largest etiologic groups. Drug resistance in P. aeruginosa isolates was high for piperacillin/tazobactam (65.6%), cefepime (56.3%), ceftazidime (46.9%) and meropenem (50.0%). Enterobacterales isolates showed slightly lower levels of resistance to piperacillin/tazobactam (32%), ceftriaxone (32%), and ceftazidime (36%). All P. aeruginosa isolates and 96% of Enterobacterales isolates were susceptible to aminoglycosides, with apramycin found to provide best-in-class coverage. Genotypic analysis of consecutive P. aeruginosa isolates in one patient revealed a frameshift mutation in the transcriptional regulator nalC that coincided with a phenotypic shift in susceptibility to β-lactams and quinolones. Conclusions Considerable levels of antimicrobial resistance may have contributed to the manifestation of bacterial superinfections in ventilated COVID-19 patients, and may in some cases mandate consecutive adaptation of antibiotic therapy. High susceptibility to amikacin and apramycin suggests that aminoglycosides may remain an effective second-line treatment of ventilator-associated bacterial pneumonia, provided efficacious drug exposure in lungs can be achieved.

Precision Medicine into Clinical Practice: A Web-Based Tool Enables Real-Time Pharmacogenetic Assessment of Tailored Treatments in Psychiatric Disorders

The management of neuropsychiatric disorders involves different pharmacological treatments. In order to perform efficacious drug treatments, the metabolism of CYP genes can help to foresee potential drug–drug interactions. The NeuroPGx software is an open-source web-based tool for genotype/diplotype/phenotype interpretation for neuropharmacogenomic purposes. The software provides information about: (i) the genotypes of evaluated SNPs (single nucleotide polymorphisms); (ii) the main diplotypes in CYP genes and corresponding metabolization phenotypes; (iii) the list of neuropsychiatric drugs with recommended dosage adjustment (according to CPIC and DPWG guidelines); (iv) the list of possible (rare) diplotypes and corresponding metabolization phenotypes. The combined application of NeuroPGx software to the OpenArray technology results in an easy, quick, and highly automated device ready to be used in routine clinical practice.

DNA-encoded chemistry technology yields expedient access to SARS-CoV-2 Mpro inhibitors

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration–approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition constant [Ki] = 20 nM). CDD-1713, a smaller two-building-block analog (MW = 353.3 g/mol) of CDD-1714, is a reversible covalent inhibitor of Mpro (Ki = 45 nM) that binds in the protease pocket, has specificity over human proteases, and shows in vitro efficacy in a SARS-CoV-2 infectivity model. Subsequently, key regions of CDD-1713 that were necessary for inhibitory activity were identified and a potent (Ki = 37 nM), smaller (MW = 323.4 g/mol), and metabolically more stable analog (CDD-1976) was generated. Thus, screening of DNA-encoded chemical libraries can accelerate the discovery of efficacious drug-like inhibitors of emerging viral disease targets.

POS0616 LONG-TERM EFFECTIVENESS AFTER MULTIPLE CYCLES WITH RITUXIMAB FOLLOWING AN ON-FLARE RETREATMENT STRATEGY IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:Rituximab is known as an efficacious drug for the treatment of Rheumatoid Arthritis (RA). The recommended administration schedule consist of 2 infusions of 1000 mg with a 2-week interval. In Belgium an on-flare retreatment strategy is followed, making evaluation of effectiveness over time challenging. Moreover the patient’s view on this strategy is unclear.Objectives:To explore long-term effectiveness and safety of rituximab in daily clinical practice in patients with RA.Methods:Data of patients diagnosed with RA and treated with rituximab in a tertiary university hospital were retrospectively collected. For every cycle, clinical data were recorded at the time of the first and second infusion, the 16-week visit and the visit on which the treating rheumatologist decided to prescribe a new cycle. Data on demographics, previous RA treatment, disease activity, patient-reported outcomes, adverse events related to rituximab, dose and number of cycles were collected from 01/01/2006 until 01/12/2019 or until discontinuation of rituximab. The visit on which rituximab was prescribed for the first time was considered as the baseline visit. The data were analysed descriptively.Results:Data of 66 patients with RA were collected. The median (IQR) age was 57.0 (47.0-65.0) years at baseline and 56% (37/66) were female. Most patients were seropositive (RF 91% and ACPA 92%), and had erosive (71%) or nodular disease (53%). The median (IQR) disease duration was 12.5 (4.0-18.3) years. In total, 94% of the patients had failed at least one other biological Disease-modifying Antirheumatic Drug (bDMARD) before starting rituximab. Overall, patients received a median (IQR) of 3 (2-7) cycles of rituximab. Seven of the 66 patients (11%) discontinued rituximab and changed to another bDMARD after a median (IQR) of 1 (1-6) cycles and 11% were treated with a lower dose than 2x1000mg. The median (IQR) interval between the first 2 cycles was 7.0 (6.0-10.0) months, after which this increased to up to one year (interval between cycle 2-3: 10.0 (7.0-13.0) months, cycle 3-4: 12.0 (7.3-15.5) months). The overall median (IQR) follow-up time was 45.5 (14.8-82.3) months. The efficacy of rituximab remained after repeated cycles: after every treatment with rituximab, a reduction in disease activity based on the disease activity score in 28 joints (DAS28) could be noticed (figure 1A). The evolution in patients’ (PaGH) and physicians’ global health (PhGH) assessment followed the same pattern as the DAS28-score (Figure 1B). High PaGH-scores could be noticed at every start of a new rituximab cycle. The proportion of patients with a PaGH-score above 20 ranged from 84% - 100%, 74% - 100% and 66% - 86% at the first infusion, second infusion and week 16 visits, respectively. Rituximab was considered to be well-tolerated. In total, 23 adverse events in 12 patients were recorded and none of them were serious.Conclusion:Rituximab can be considered a highly efficacious drug for RA treatment in daily practice. There were no major side effects and there was an increasing treatment interval over time. However, a healthy survivor effect should be kept in mind when interpreting the results. It should be noted that with the on-flare retreatment strategy, every new rituximab cycle was preceded by a rise in PaGH-scores, which reflects a state of impaired wellbeing reported by patients. This should be further studied with qualitative methods and in a randomized trial setting comparing on-flare with fixed-interval retreatment to evaluate optimal effectiveness.Figure 1.Evolution in median - interquartile range disease activity (DAS28CRP) (A) and patients’ (PaGH) and physicians’ global health (PhGH) (B) over the different rituximab cycles. The disease activity, PaGH and PhGH were measured at baseline, the time of the first and second infusion, W16 and the visit on which a new rituximab cycle was prescribed. The dotted lines represent a DAS28CRP-score of 2.6 (remission cut-off) and 3.2 (low disease activity cut-off). C: cycle; W: week; VAS: visual analogue scale.Disclosure of Interests:None declared

Recent perspectives of nanotechnology in burn wounds management: a review

Objective: The burden of the management of problematic skin wounds characterised by a compromised skin barrier is growing rapidly. Almost six million patients are affected in the US alone, with an estimated market of $25 billion annually. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. Novel strategies are needed for faster healing by reducing infection, moisturising the wound, stimulating the healing mechanisms, speeding up wound closure and reducing scar formation. Methods: A systematic review of qualitative studies was conducted on the recent perspectives of nanotechnology in burn wounds management. Pubmed, Scopus, EMBASE, CINAHL and PsychINFO databases were all systematically searched. Authors independently rated the reporting of the qualitative studies included. A comprehensive literature search was conducted covering various resources up to 2018–2019. Traditional techniques aim to simply cover the wound without playing any active role in wound healing. However, nanotechnology-based solutions are being used to create multipurpose biomaterials, not only for regeneration and repair, but also for on-demand delivery of specific molecules. The chronic nature and associated complications of nonhealing wounds have led to the emergence of nanotechnology-based therapies that aim at facilitating the healing process and ultimately repairing the injured tissue. Conclusion: Nanotechnology-based therapy is in the forefront of next-generation therapy that is able to advance wound healing of hard-to-heal wounds. In this review, we will highlight the developed nanotechnology-based therapeutic agents and assess the viability and efficacy of each treatment. Herein we will explore the unmet needs and future directions of current technologies, while discussing promising strategies that can advance the wound-healing field

Antimicrobial susceptibility patterns of respiratory Gram-negative bacterial isolates from COVID-19 patients in Switzerland

BackgroundBacterial superinfections associated with COVID-19 are common in ventilated ICU patients and impact morbidity and lethality. However, the contribution of antimicrobial resistance to the manifestation of bacterial infections in these patients has yet to be elucidated.MethodsWe collected 70 Gram-negative bacterial strains, isolated from the lower respiratory tract of ventilated COVID-19 patients in Zurich, Switzerland between March and May 2020. Species identification was performed using MALDI-TOF; antibiotic susceptibility profiles were determined by EUCAST disk diffusion and CLSI broth microdilution assays. Selected Pseudomonas aeruginosa isolates were analyzed by whole-genome sequencing.ResultsP. aeruginosa (46%) and Enterobacterales (36%) comprised the two largest etiologic groups. Drug resistance in P. aeruginosa isolates was high for piperacillin/tazobactam (65.6%), cefepime (56.3%), ceftazidime (46.9%) and meropenem (50.0%). Enterobacterales isolates showed slightly lower levels of resistance to piperacillin/tazobactam (32%), ceftriaxone (32%), and ceftazidime (36%). All P. aeruginosa isolates and 92% of Enterobacterales isolates were susceptible to aminoglycosides, with apramycin found to provide best-in-class coverage. Genotypic analysis of consecutive P. aeruginosa isolates in one patient revealed a frameshift mutation in the transcriptional regulator nalC that coincided with a phenotypic shift in susceptibility to β-lactams and quinolones.ConclusionsConsiderable levels of antimicrobial resistance may have contributed to the manifestation of bacterial superinfections in ventilated COVID-19 patients, and may in some cases mandate consecutive adaptation of antibiotic therapy. High susceptibility to amikacin and apramycin suggests that aminoglycosides may remain an effective second-line treatment of ventilator-associated bacterial pneumonia, provided efficacious drug exposure in lungs can be achieved.

HRWR: Predicting Potential Efficacious Drug Combination Based on Hypergraph Random Walk with Restart

Some studies have shown that efficacious drug combination can increase the therapeutic effect, and decrease drug toxicity and side-effects. Thus, drug combinations have been widely used in the treatment of complex diseases, especially cancer. However, experiment-based methods are extremely costly in time and money. Computational models can greatly reduce the cost, but most of the models do not use the data of more than two drugs and lose a lot of useful information. Here, we used high-order drug combination information and developed a hypergraph random walk with restart model (HRWR) for efficacious drug combination prediction.As a result, compared with the other methods by leave-one-out cross-validation (LOOCV), the Area Under Receiver Operating Characteristic Curve (AUROC) of the HRWR algorithm were higher than others. Moreover, the case studies of lung cancer, breast cancer, and colorectal cancer showed that HRWR had a powerful ability to predict potential efficacious combinations, which provides new prospects for cancer treatment. The code and dataset of HRWR are freely available at https://github.com/wangqi27/HRWR.

Asymptomatic recrudescence after artemether–lumefantrine treatment for uncomplicated falciparum malaria: a systematic review and meta-analysis

Background In clinical trials of therapy for uncomplicated Plasmodium falciparum, there are usually some patients who fail treatment even in the absence of drug resistance. Treatment failures, which can be due to recrudescence or re-infection, are categorized as ‘clinical’ or ‘parasitological’ failures, the former indicating that symptoms have returned. Asymptomatic recrudescence has public health implications for continued malaria transmission and may be important for the spread of drug-resistant malaria. As the number of recrudescences in an individual trial is often low, it is difficult to assess how commonplace asymptomatic recrudescence is, and with what factors it is associated. Methods A systematic literature review was carried out on clinical trials of artemether-lumefantrine (AL) in patients seeking treatment for symptomatic uncomplicated falciparum malaria, and information on symptoms during treatment failure was recorded. Only treatment failures examined by polymerase chain reaction (PCR) were included, so as to exclude re-infections. A multivariable Bayesian regression model was used to explore factors potentially explaining the proportion of recrudescent infections which are symptomatic across the trials included in the study. Results Across 60 published trials, including 9137 malaria patients, 37.8% [95% CIs (26.6–49.4%)] of recrudescences were symptomatic. A positive association was found between transmission intensity and the observed proportion of recrudescences that were asymptomatic. Symptoms were more likely to return in trials that only enrolled children aged < 72 months [odds ratio = 1.62, 95% CIs (1.01, 2.59)]. However, 84 studies had to be excluded from this analysis, as recrudescences were not specified as symptomatic or asymptomatic. Conclusions AL, the most widely used treatment for uncomplicated P. falciparum in Africa, remains a highly efficacious drug in most endemic countries. However in the small proportion of patients where AL does not clear parasitaemia, the majority of patients do not develop symptoms again and thus would be unlikely to seek another course of treatment. This continued asymptomatic parasite carriage in patients who have been treated may have implications for drug-resistant parasites being introduced into high-transmissions settings.

Crystal-Structures-Guided Design of Fragment-Based Drugs for Inhibiting the Main Protease of SARS-CoV-2

Since the beginning of the COVID-19 pandemic, researchers and scientists across the globe are racing to find a cure for the highly contagious infectious disease caused by the SARS-CoV-2 virus. Despite many promising ongoing progress, there are currently no FDA approved drugs to treat infected patients. Among the various protein targets of SARS-CoV-2 virus, the main protease (Mpro) has attracted most interests. Recently, the crowdsourcing of drug discovery for inhibiting Mpro have yielded a plenty of drug fragments resolved inside the active site of Mpro via the crystallography method. Following the principle of fragment-based drug design (FBDD), we are motivated to design a potent drug molecule through merging several of these newly discovered drug fragments. Among various designed ligands, we found that B19 by merging three fragments JFM, U0P and HWH is the most stable one, evidenced through extensive (~10 μs totally) all-atom molecular dynamics simulation. We further estimated that the binding free energy of B19 is comparable or even a little better than that of a native protein ligand processed by Mpro. Our promising results suggest that B19 can potentially be an efficacious drug molecule for inhibiting Mpro of SARS-CoV-2.

Evaluation of the Laxative activity of Saponin Enriched Hydroethanolic Pericarp extract of Sapindus emarginatus in Animal models

Background: Constipation is a common, predominant, chronic gastrointestinal functional disorder. The drugs available to treat constipation are limited because of their side effects in long term use. So we need of efficacious drug to treat constipation. Sapindus emarginatus Vahl belongs to the family Sapindaceae, commonly known as soapnut. Traditionally used for the antipruritic, antifertility, constipation, and anti-inflammatory agents. Objective: The present study was undertaken to evaluate the laxative activity of hydroethanolic pericarp extract of Sapindus emarginatus (HESE) in animal models. Methods: The saponin content in extract was measured by gravimetric analysis. The laxative activity of hydroethanolic pericarp extract of Sapindus emarginatus is evaluated by the weight of feces matter, charcoal meal hyperperistalsis test, and loperamide induced constipation model. Results: The saponin content of the soapnut pericarp was 13.48 % and the extract was found to be 11.92 %. The results obtained from these models showed a significant dose-dependent increase in fecal weight, peristalsis index, and moisture content compared to control animals. Conclusion: The present study concluded that the oral administration of HESE showed a significant laxative activity by using different animal models. The presence of triterpene saponins is responsible for this activity. Further studies are needed to confirm their mechanism behind the laxative effect. The administration of extract was found to be a valid candidate in constipation therapy.