Anti-infective Agents Research Articles

In silico Exploration of the Therapeutic Potential of Alkaloids as Anti-infective Agents

Background: Alkaloids are important phytoconstituents obtained from various plant sources. Methods: The main objective of the study was to evaluate the anti-infective potential of alkaloids against 14α-demethylase, transpeptidase, and omicron spike protein using molecular docking studies. The potential constituents were identified and an ADMET study was performed. Results: The study concluded that reserpine and tubocurarine exhibited potential activity against the three tested enzymes with good ADMET profile. Conclusion: Reserpine and tubocurarine can further be explored to attain new candidates as antiinfective agents.

A liquid chromatography-tandem mass spectrometry method to determine total matrine residues in edible porcine tissues and its application in a tissue residue depletion study

Matrine (MT), a phytochemical with various anti-infective activities, is expected to become a therapeutic agent against bacterial, viral, and parasitic infections in pigs. However, food safety risks associated with MT have not yet been evaluated. In the present study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to determine total MT residues in edible porcine tissues. The tissue samples were hydrolyzed with trypsin to release non-extractable MT. The hydrolysates were extracted with a trichloroacetic acid solution. Tissue extracts were purified using solid-phase extraction and subjected to LC-MS/MS. The method was fully validated according to the United States Food and Drug Administration (USFDA) guidelines and applied to investigate the tissue residue depletion of MT in pigs. Significant accumulation of MT was observed in edible porcine tissues. Notably, MT showed no persistent tissue residue in this study and could be accepted as a safe anti-infective agent in pigs.

Drugs Targeting Sirtuin 2 Exhibit Broad-Spectrum Anti-Infective Activity.

Direct-acting anti-infective drugs target pathogen-coded gene products and are a highly successful therapeutic paradigm. However, they generally target a single pathogen or family of pathogens, and the targeted organisms can readily evolve resistance. Host-targeted agents can overcome these limitations. One family of host-targeted, anti-infective agents modulate human sirtuin 2 (SIRT2) enzyme activity. SIRT2 is one of seven human sirtuins, a family of NAD+-dependent protein deacylases. It is the only sirtuin that is found predominantly in the cytoplasm. Multiple, structurally distinct SIRT2-targeted, small molecules have been shown to inhibit the replication of both RNA and DNA viruses, as well as intracellular bacterial pathogens, in cell culture and in animal models of disease. Biochemical and X-ray structural studies indicate that most, and probably all, of these compounds act as allosteric modulators. These compounds appear to impact the replication cycles of intracellular pathogens at multiple levels to antagonize their replication and spread. Here, we review SIRT2 modulators reported to exhibit anti-infective activity, exploring their pharmacological action as anti-infectives and identifying questions in need of additional study as this family of anti-infective agents advances to the clinic.

What is confirmed in the treatment of sepsis? : An update

Sepsis is defined as "being evoked as a life-threatening organ dysfunction caused by an inadequate host response to infection". The most recent German S3 guidelines were published in 2018 and the Surviving Sepsis Campaign (SSC) last published the current recommendations for the treatment of sepsis and septic shock in 2021. This article explores and discusses which evidence in the treatment of sepsis and septic shock has been confirmed. Discussion of the 2018 German S3 guidelines, supplementation of the content of the 2021 international guidelines and recent research results since 2021. The primary objective for managing sepsis and septic shock still includes rapid identification, early initiation of anti-infective treatment, and focus cleansing when feasible. In addition, the focus is on hemodynamic stabilization, including the early use of vasopressors for prevention of hypervolemia and, if necessary, the use of organ support procedures. Supportive treatment, such as the administration of corticosteroids and the use of apheresis, can be advantageous in specific scenarios. The focus is increasingly shifting towards post-intensive care unit (ICU) follow-up care, improving the quality of life after surviving sepsis and the close involvement of relatives of the patient. Despite the fact that considerable progress has been made in understanding the pathophysiology and treatment of sepsis, the early administration of anti-infective agents, focus control, nuanced volume therapy and the use of catecholamines continue to be fundamental to sepsis management. New recommendations emphasize the early use of vasopressors (primarily norepinephrine) and the administration of corticosteroids, especially in cases of septic shock and pneumonia.

Role of Natural Phytoconstituents as a Potential Bioenhancer of Anti-Cancer and Anti-Microbial Agents: Spotlight on the Mechanism of Action, Clinical Studies and Patents

A drug design strategy with reduced side effects and economic feasibility is desirable for fatal diseases. Increasing the bioavailability of a drug using a bioenhancer is a smart strategy. Herbal/natural bioenhancers with no probable side effects are an ideal choice to enhance the pharmacokinetics of a therapeutic drug synergistically. The mechanism of bioenhancers relies on the retention of the drug molecule in the cell without causing any changes in the metabolic activity. Most of the herbal bioenhancers achieve this feat by inhibiting metabolic enzymes such as cytochrome P450 and Uridine 5′-diphospho-glucuronosyltransferase. The efflux pump p-glycoprotein, responsible for removal of xenobiotics, is also inhibited by herbal/natural bioenhancers. The increased bioavailability because of the higher Cmax and tmax of chemotherapeutics or anti-infectious agents such as rifampicin can result in a lower drug dosage regimen. The reduction in drug dosage is directly linked to fewer side effects and economic viability. Further, there is a significant effort in clinical trials to incorporate bioenhancers in drug regimens for cancer. The role of herbal/natural bioenhancers and their potential to augment the bioavailability of therapeutics used in cancer and infectious diseases, with a focus on the mechanisms of action, clinical studies and patents, have been summarized in this review article.

Anti-infective properties of mung bean (Vigna radiata (L.)R. Wilczek) coat extract on Pseudomonas aeruginosa-infected Caenorhabditis elegans: Transcriptomics and pathway analysis

Ethnopharmacological relevanceMung bean coat has long been known for its wide-ranging health benefits, including antibacterial, anti-inflammatory, and immune-modulatory properties. For many years in China, mung beans have been employed in the therapeutic management of inflammation induced by pathogenic bacteria infection, yet the precise underlying protective mechanisms remain to be comprehensively elucidated. Aim of the studyGiven the growing concern over antibiotic resistance, there is a necessity to explore new anti-infective agents. Here, the anti-infective properties of Mung bean coat extract (MBCE) were investigated using a model of Pseudomonas aeruginosa-infected nematodes. Materials and methodsThe protective effects of MBCE on Pseudomonas aeruginosa (PA14) infected nematodes were assessed by lifespan assay, reactive oxygen species (ROS) levels, transcriptomics, and Quantitative real-time PCR (qRT-PCR). ResultsMBCE significantly improved the survival rates and reduced ROS levels in infected worms. Transcriptomic profiling disclosed predominant KEGG pathway enrichments in immune responses, energy metabolism processes such as oxidative phosphorylation and the tricarboxylic acid cycle, alongside aging-related neurodegenerative diseases and longevity regulatory pathways like PI3K-AKT, MAPK, mTOR, and FOXO. qRT-PCR validation showed that MBCE upregulated antimicrobial peptides (spp-3, lys-1, lys-7, abf-2, cnc-2, nlp-33, clec-85), gram-negative responses (irg-3, src-2, grd-3, col-179), and mitochondrial function (mev-1) gene expressions, while downregulated insulin signaling-related (age-1, akt-1, akt-2, daf-15) gene expressions. Mutant strains lifespan analysis indicated that the nsy-1, sek-1, pmk-1, daf-2, aak-2, sir-2.1, and skn-1 were necessary for lifespan extension mediated by MBCE under PA14 infection, but not clk-1, isp-1, mev-1, or daf-16. ConclusionCollectively, our findings suggested that MBCE increased the survival rates of PA14-infected worms by activating downstream antimicrobial and antioxidant gene expressions through modulation of MAPK, daf-2, aak-2, sir-2.1, and skn-1 pathways. The research underscored the potential of natural plant compounds to strengthen the body's defenses against infections, potentially mitigating harmful ROS levels and improving survival. Additionally, these findings elucidated the mechanisms by which these plant-derived compounds enhance the immune system, implying their potential utility as dietary supplements or as an alternative to conventional antibiotics.

Novel antimicrobial peptides based on Protegrin-1: In silico and in vitro assessments

The development of antibiotic resistance has caused significant health problems. Antimicrobial peptides (AMPs) are considered next-generation antibiotics. Protegrin-1 (PG-1) is a β-hairpin AMP with a membrane-binding capacity. This study used twelve PG-1 analogs with different amino acid substitutions. Coarse-grained molecular dynamics (MD) simulations were used to assess these analogs, and their physicochemical properties were computed using the Antimicrobial Peptide Database. Three AMPs, PEP-D, PEP-C, and PEP-H, were chosen and synthesized for antibacterial testing. The microbroth dilution technique and hemolytic assays evaluated the antimicrobial efficacy and cellular toxicity. The checkerboard method was used to test the combined activity of AMP and standard antibiotics. Cell membrane permeability and electron microscopy were used to evaluate the mode of action. The chemical stability of the selective AMP, PEP-D, was assessed by a validated HPLC method. PEP-D consists of 16–18 amino acid residues and has a charge of +7 and a hydrophobicity of 44 %, similar to PG-1. It can efficiently inactivate bacteria by disrupting cell membranes and significantly reducing hemolytic activity. Chemical stability studies indicated that AMP was stable at 40 °C for six months under autoclave conditions. This study could introduce the potential therapeutic application of selective AMP as an anti-infective agent.

Pathogen-induced diseases of the spinal cord and adjacent structures

Pathogen-induced myelitis is an inflammatory disease of the spinal cord that can be caused by various pathogens including viruses, bacteria, fungi or parasites. The most frequent viral pathogens include herpes and enteroviruses, while bacterial myelitis can be caused by, e.g., Mycobacterium tuberculosis, Borrelia burgdorferi and Treponema pallidum. Fungi such as Candida and Aspergillus and parasites such as Toxoplasma gondii and schistosomes can also cause myelitis. The main symptom is subacute paraplegia with motor, sensory and autonomic deficits to varying degrees, often accompanied by fever and ageneral malaise. Following athorough clinical examination and review of the medical history diagnostic imaging procedures, such as magnetic resonance imaging (MRI) along with cerebrospinal fluid analysis and blood tests that include antibody testing are warranted. The treatment is directed at the cause of the myelitis and mostly with anti-infective agents but for some viral pathogens no specific treatment is available and the only option is asymptomatic treatment. The prognosis is very variable and depends on the etiology and severity of the disease. Afast diagnosis and targeted treatment are crucial to achieve agood outcome.

In vitro Tolerance of Staphylococcus haemolyticus and Candida albicans Biofilms to Dalbavancin and Anidulafungin

Background: Concerns about infections resulting from bacterial biofilm formation in invasive devices such as catheters and prostheses are becoming widespread in the public health domain. Staphylococcus haemolyticus, a coagulase-negative bacterium, and Candida albicans, a yeast, have become recurrent pathogens of these diseases because their presence in these devices enhances the likelihood of infection. It is believed that these microorganisms produce biofilms, which complicate treatment and slow the patient´s recuperation. Dalba-vancin is a semisynthetic, lipoglycopeptide-class antibiotic utilized as an anti-infective agent to break down gram-positive bacteria biofilms. Anidulafungin is an echinocandin class anti-fungal medication that works very well against resistant yeast strains and removes biofilms. Objective: This study aims to examine the anti-infective agents´ tolerance to the biofilms of Staphylococcus haemolyticus and Candida albicans. Methods: Polymicrobial biofilms were grown in a CDC Biofilm Reactor (CBR) for use in in vitro experiments. Results: When dalbavancin maintained its antibiotic activities against Staphylococcus hae-molyticus in comparison with their activity against the sessile forms, the antifungal anidula-fungin lost efficacy in eliminating Candida albicans. Conclusion: The planktonic forms of microbes are examined in relation to the tolerance to these anti-infective drugs.

Anticipating Viral Challenges: A Perspective on Phytochemicals Against Existing and Emerging Viruses

Abstract: Viral infections impact millions of individuals annually and in 2018, the WHO called for global preparedness to address potential high-mortality pathogens, referred to as "Pathogen X," which can include fungi, viruses, parasites, or prions. The constant evolution of RNA viruses leads to continually changing variants, challenging the effectiveness of vac-cines and drugs. In underserved healthcare regions, plant-based phytochemicals offer prom-ise in combating viral diseases due to their ready availability, proven effectiveness, and low toxicity. Amidst the evolving virus variants and recurring fatal outbreaks, especially in re-source-constrained regions, phytochemicals hold promise as potential anti-infective agents. This review delves into plant-based antivirals, aiming to update plant-derived antiviral com-pounds' status against existing and emerging viruses from 2019 to 2023. The study aimed to identify active components from medicinal plants with IC50 and EC50 values against human-infecting viruses. It utilized in vitro and in vivo methods to predict phytochemical mechanisms and enhance bioavailability. Among the phytochemicals studied as antivirals, Emodin, Quercetin, Myricetin, Resveratrol, and Silymarin demonstrated efficacy against multiple viruses. Notably, certain plant compounds were effective against multiple viruses and could serve as potential antiviral treatments. Overall, the review illustrates that harness-ing plant-derived compounds shows promise in combating current and evolving infectious threats.

Does the Incorporation of Graphene Oxide into PMMA Influence its Antimicrobial Activity?

The increase in infectious diseases mediated by oral bacteria has been one of the most potent threats to human health, specifically to the elderly. Researchers seek to incorporate antimicrobial nanomaterials into PMMA to control the colonization of microorganisms and reduce deadly diseases. To conduct a systematic review to answer the question: "Does graphene oxide incorporated into polymethylmethacrylate influence its antimicrobial activity?" The electronic search was performed in PubMed, Embase, Web of Science, Scopus, and Google Scholar databases, and articles published until October 2021 were selected. The search terms were: ("acrylic resin" OR PMMA) AND (graphene OR "oxide graphene") AND (antimicrobial OR antibacterial OR "anti-infective agent"). The risk of bias analysis of the articles was performed using the quasi-experimental study assessment tool adapted from the JBI. Two hundred and fifty-nine articles were found in the databases. After removing the duplicates, 245 were analyzed by title and abstract. Of these, 06 were selected for full reading, of which 03 met the eligibility criteria and were included in this systematic review. This systematic review's findings can infer that the incorporation of graphene in the form of graphene-based coatings to PMMA showed antimicrobial effectiveness.

PVC membrane bulk optode incorporating 4-nitrobenzo-15-crown-5 and sodium tetrakis(1-imidazolyl) borate for the pico-molar determination of silver ion in pharmaceutical formulation

Silver ion (Ag+) is of harmful effects to both environment and human health. Ag+ soluble compounds and salts is used in treating mental illness, epilepsy, nicotine addiction, gastroenteritis, and infectious diseases, including syphilis and gonorrhea, and as anti-infective dermatological agent for controlling nose bleeding. However, high Ag+ doses cause several harmful effects to human health such as irreversible pigmentation of skin and eye, and problems to liver and kidney. A bulk membrane Optode is proposed in this work to measure the Ag+ concentration in the pharmaceutical formulations. The membrane optode is prepared from the ionophore 4-nitobenzo-15-crown-5, the ion-exchanger sodium tetrakis (imidazolyl) borate, the plasticizer o-nitrophenyl octyl ether, and the chromoionophore ETH 5294; these components are dissolved in the PVC/THF slurry to form the membrane. The optode is studied by atomic force microscope and UV–visible spectrophotometer, and its spectrum exhibits two maximum wavelengths of 550 and 665 nm, and response for Ag+ at these maximum wavelengths is reproducible in the concentration range of 10–11 to 10–8 M using acetate buffer of pH 5.0, with very low detection limit of 8.8 × 10–12 M. The most important feature in this work is the selectivity improvement for Ag+ over all interfering ions; the selectivity coefficient logarithm logKAg+,cationopt\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${logK}_{Ag+, cation}^{opt}$$\\end{document} is found to be − 4.3 for Cu2+, − 5.6 for Ni2+ and − 5.0 for Cd2+. The response mechanism is studied by FTIR, and it depends on ion-exchange of Ag+ and sodium imidazolyl borate, followed by the host–guest complexation between Ag+ and the crown ionophore, which is accompanied by concomitant deprotonation of the chromoionphore. The optode has a response time of 2–3 min within lifetime of 10 days with the same response. The optode can be applied successfully for Ag+ determination in the pharmaceutical formulation, PinkEye Relief® eye drop, which is used for treating inflammation, redness and water discharge of the eye; the high recovery and low standard deviation of the results using calibration curve method confirm the accuracy and precision of the proposed optode for its application in real samples.

From Traditional Use to Modern Evidence: The Medicinal Chemistry of Antimalarials from Genus Artemisia.

While the use of plants in traditional medicine dates back to 1500 B.C., modern advancements led to the development of innovative therapeutic techniques. On the other hand, in the field of anti-infective agents, lack of efficacy and the onset of resistance stimulate the search for novel agents. Genus Artemisia is one of the most diverse among perennial plants with a variety of species, properties, and chemical components. The genus is known for its therapeutic values and, in particular, for its role in the origin of antimalarial agents derived from artemisinin. In this review, we aim to provide an updated overview of the evolution of natural and natureinspired compounds related to the genus Artemisia that have been proven, in vitro and in vivo, to possess antimalarial properties. An overview of the chemical composition and a description of the ethnopharmacological aspects will be presented, as well as an updated report on in vitro and in vivo evidence that allowed the translation of artemisinin and its derivatives from traditional chemistry into modern medicinal chemistry. The biological and structural properties will be discussed, also dedicating attention to the challenging tasks that still are open, such as the identification of optimal combination strategies, the routes of administration, and the full assessment of the mechanism of action.

Chemical optimization and derivatization of micrococcin p2 to target multiple bacterial infections: new antibiotics from thiopeptides.

Antimicrobial resistance poses a significant threat to humanity, and the development of new antibiotics is urgently needed. Our research has focused on thiopeptide antibiotics such as micrococcin P2 (MP2) and derivatives thereof as new anti-infective agents. Thiopeptides are sulfur-rich, structurally complex substances that exhibit potent activity against Gram-positive pathogens and Mycobacteria species, including clinically resistant strains. The clinical development of thiopeptides has been hampered by the lack of efficient synthetic platforms to conduct detailed structure-activity relationship studies of these natural products. The present contribution touches upon efficient synthetic routes to MP2 that laid the groundwork for clinical translation. The medicinal chemistry campaign on MP2 has been guided by computational molecular dynamic simulations and parallel investigations to improve drug-like properties, such as enhancing the aqueous solubility and optimizing antibacterial activity. Such endeavors have enabled identification of promising lead compounds, AJ-037 and AJ-206, against Mycobacterium avium complex (MAC). Extensive in vitro studies revealed that these compounds exert potent activity against MAC species, a subspecies of non-tuberculous mycobacteria (NTM) that proliferate inside macrophages. Two additional pre-clinical candidates have been identified: AJ-024, for the treatment of Clostridioides difficile infections, and AJ-147, for methicillin-resistant Staphylococcus aureus impetigo. Both compounds compare quite favorably with current first-line treatments. In particular, the ability of AJ-147 to downregulate pro-inflammatory cytokines adds a valuable dimension to its clinical use. In light of above, these new thiopeptide derivatives are well-poised for further clinical development.

Repurposing Anidulafungin for Alzheimer's Disease via Fragment-Based Drug Discovery.

The misfolding and aggregation of beta-amyloid (Aβ) peptides have been implicated as key pathogenic events in the early stages of Alzheimer's disease (AD). Inhibiting Aβ aggregation represents a potential disease-modifying therapeutic approach to AD treatment. Previous studies have identified various molecules that inhibit Aβ aggregation, some of which share common chemical substructures (fragments) that may be key to their inhibitory activity. Employing fragment-based drug discovery (FBDD) methods may facilitate the identification of these fragments, which can subsequently be used to screen new inhibitors and provide leads for further drug development. In this study, we used an in silico FBDD approach to identify 17 fragment clusters that are significantly enriched among Aβ aggregation inhibitors. These fragments were then used to screen anti-infective agents, a promising drug class for repurposing against amyloid aggregation. This screening process identified 16 anti-infective drugs, 5 of which were chosen for further investigation. Among the 5 candidates, anidulafungin, an antifungal compound, showed high efficacy in inhibiting Aβ aggregation in vitro. Kinetic analysis revealed that anidulafungin selectively blocks the primary nucleation step of Aβ aggregation, substantially delaying Aβ fibril formation. Cell viability assays demonstrated that anidulafungin can reduce the toxicity of oligomeric Aβ on BV2 microglia cells. Molecular docking simulations predicted that anidulafungin interacted with various Aβ species, including monomers, oligomers, and fibrils, potentially explaining its activity against Aβ aggregation and toxicity. This study suggests that anidulafungin is a potential drug to be repurposed for AD, and FBDD is a promising approach for discovering drugs to combat Aβ aggregation.

Synthesis of Dual-Responsive Amphiphilic Glycomacromolecules: Controlled Release of Glycan Ligands via pH and UV Stimuli.

This work presents a versatile strategy for the synthesis of dual stimuli-responsive amphiphilic glycomacromolecules with tailored release properties. Amphiphilic precision glycomacromolecules (APGs) derived from tailor-made building blocks using solid phase polymer synthesis form glycofunctionalized micelles, a versatile class of materials with applications in drug delivery, as antiinfection agents as well as simple cell mimetics. In this work, this concept is extended by integrating cleavable building blocks into APGs now allowing stimuli-responsive release of glycan ligands or destruction of the micelles. This study incorporates a newly designed acid-labile building block, 4-(4-(((((9H-fluoren-9-yl)methoxy)carbonyl)amino)methyl)-1,3-dioxolan-2-yl)benzoic acid (DBA), suitable also for other types of solid phase or amide chemistry, and an established UV-cleavable 2-nitrobenzyl linker (PL). The results demonstrate that both linkers can be cleaved independently and thus allow dual stimuli-responsive release from the APG micelles. By choosing the APG design e.g., placing the cleavable linkers between glycomacromolecular blocks presenting different types of carbohydrates, they can tune APG and micellar stability as well as the interaction and cluster formation with a carbohydrate-recognizing lectin. Such dual-responsive glycofunctionalized micelles have wide potential for use in drug delivery applications or for the development as anti-adhesion agents in antiviral and antibacterial treatments.

Intersite communication in dimeric enzymes highlighted by structural and thermodynamic analysis of didansyltyrosine binding to thymidylate synthases

Intersite communication in dimeric enzymes, triggered by ligand binding, represents both a challenge and an opportunity in enzyme inhibition strategy. Though often understestimated, it can impact on the in vivo biological mechansim of an inhibitor and on its pharmacokinetics. Thymidylate synthase (TS) is a homodimeric enzyme present in almost all living organisms that plays a crucial role in DNA synthesis and cell replication. While its inhibition is a valid strategy in the therapy of several human cancers, designing specific inhibitors of bacterial TSs poses a challenge to the development of new anti-infective agents. N,O-didansyl-l-tyrosine (DDT) inhibits both Escherichia coli TS (EcTS) and Lactobacillus casei TS (LcTS). The available X-ray structure of the DDT:dUMP:EcTS ternary complex indicated an unexpected binding mode for DDT to EcTS, involving a rearrangement of the protein and addressing the matter of communication between the two active sites of an enzyme dimer. Combining molecular-level information on DDT binding to EcTS and LcTS extracted from structural and FRET-based fluorometric evidence with a thermodynamic characterization of these events obtained by fluorometric and calorimetric titrations, this study unveiled a negative cooperativity between the DDT bindings to the two monomers of each enzyme dimer. This result, complemented by the species-specific thermodynamic signatures of the binding events, implied that communication across the protein dimer was triggered by the first DDT binding. These findings could challenge the conventional understanding of TS inhibition and open the way for the development of novel TS inhibitors with a different mechanism of action and enhanced efficacy and specificity.

Strategic Single-Residue Substitution in the Antimicrobial Peptide Esc(1-21) Confers Activity against Staphylococcus aureus, Including Drug-Resistant and Biofilm Phenotype.

Staphylococcus aureus, a bacterium resistant to multiple drugs, is a significant cause of illness and death worldwide. Antimicrobial peptides (AMPs) provide an excellent potential strategy to cope with this threat. Recently, we characterized a derivative of the frog-skin AMP esculentin-1a, Esc(1-21) (1) that is endowed with potent activity against Gram-negative bacteria but poor efficacy against Gram-positive strains. In this study, three analogues of peptide 1 were designed by replacing Gly8 with α-aminoisobutyric acid (Aib), Pro, and dPro (2-4, respectively). The single substitution Gly8 → Aib8 in peptide 2 makes it active against the planktonic form of Gram-positive bacterial strains, especially Staphylococcus aureus, including multidrug-resistant clinical isolates, with an improved biostability without resulting in cytotoxicity to mammalian cells. Moreover, peptide 2 showed a higher antibiofilm activity than peptide 1 against both reference and clinical isolates of S. aureus. Peptide 2 was also able to induce rapid bacterial killing, suggesting a membrane-perturbing mechanism of action. Structural analysis of the most active peptide 2 evidenced that the improved biological activity of peptide 2 is the consequence of a combination of higher biostability, higher α helical content, and ability to reduce membrane fluidity and to adopt a distorted helix, bent in correspondence of Aib8. Overall, this study has shown how a strategic single amino acid substitution is sufficient to enlarge the spectrum of activity of the original peptide 1, and improve its biological properties for therapeutic purposes, thus paving the way to optimize AMPs for the development of new broad-spectrum anti-infective agents.

Impact of the COVID-19 Pandemic on Pharmacist Interventions: A Retrospective Study with Inpatients in a University Hospital.

Despite growing interest in understanding the challenges faced by multidisciplinary health teams during the COVID-19 pandemic, there is a lack of studies specifically focusing on changes in pharmacist interventions and drug-related problems. To analyze and compare the interventions performed by pharmacists during comprehensive medication management in the adult intensive care unit and general internal medicine ward of the University Hospital of the University of São Paulo, Brazil, for defined periods before the onset of the COVID-19 pandemic and during the pandemic itself. All pharmacist interventions performed in relation to inpatient prescriptions from March to December 2019 (before the pandemic) and from March to December 2021 (during the pandemic) were collected and tabulated. These interventions were then classified according to the Pharmaceutical Care Network Europe (PCNE) system, version 9.1, and categorized based on first-level codes of the Anatomical Therapeutic Chemical classification system. The analysis revealed substantial changes in the patterns of pharmacist interventions and the therapeutic classes of drugs for COVID-19-positive and COVID-19-negative patients during the pandemic relative to patients in the pre-pandemic period. Among COVID-19-positive patients, interventions were predominantly related to enhancing patient safety (PCNE code P2), drug selection (C1), dose selection (C3), prescribing and dispensing processes (C5), the drug-use process (C6), and patient transfers between different levels of care (C8). The drug-related problems addressed by pharmacist interventions primarily involved COVID-19-positive patients in the pandemic period and were related to systemic hormonal preparations (excluding sex hormones and insulins), anti-infective agents for systemic use, nervous system and drugs for the blood and blood-forming organs. The results of this study highlight the adaptability and competence of pharmacists in responding to critical scenarios such as the COVID-19 pandemic. These scenarios are characterized by new work dynamics, the hiring of additional professionals, an increase in the number of beds, the rapid evolution of evidence-based information, and drug shortages that necessitate the use of alternative medications. Pharmacists play a crucial role in ensuring patient safety during these difficult times.

Strathclyde minor groove binders (S-MGBs) with activity against Acanthamoeba castellanii.

Acanthamoeba spp. is the causative agent of Acanthamoeba keratitis and granulomatous amoebic encephalitis. Strathclyde minor groove binders (S-MGBs) are a promising new class of anti-infective agent that have been shown to be effective against many infectious organisms. To synthesize and evaluate the anti-Acanthamoeba activity of a panel of S-MGBs, and therefore determine the potential of this class for further development. A panel of 12 S-MGBs was synthesized and anti-Acanthamoeba activity was determined using an alamarBlue™-based trophocidal assay against Acanthamoeba castellanii. Cross-screening against Trypanosoma brucei brucei, Staphylococcus aureus and Escherichia coli was used to investigate selective potency. Cytotoxicity against HEK293 cells allowed for selective toxicity to be measured. DNA binding studies were carried out using native mass spectrometry and DNA thermal shift assays. S-MGB-241 has an IC50 of 6.6 µM against A. castellanii, comparable to the clinically used miltefosine (5.6 µM) and negligible activity against the other organisms. It was also found to have an IC50 > 100 µM against HEK293 cells, demonstrating low cytotoxicity. S-MGB-241 binds to DNA as a dimer, albeit weakly compared to other S-MGBs previously studied. This was confirmed by DNA thermal shift assay with a ΔTm = 1 ± 0.1°C. Together, these data provide confidence that S-MGBs can be further optimized to generate new, potent treatments for Acanthameoba spp. infections. In particular, S-MGB-241, has been identified as a 'hit' compound that is selectively active against A. castellanii, providing a starting point from which to begin optimization of DNA binding and potency.