In Vitro and In Vivo Demonstration of Ultraefficient and Broad-Spectrum Antibacterial Agents for Photodynamic Antibacterial Chemotherapy

2021 ◽  
Vol 13 (10) ◽  
pp. 11588-11596
Author(s):  
Qicai Xiao ◽  
Bingjie Mai ◽  
Yichu Nie ◽  
Chuang Yuan ◽  
Menghua Xiang ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antibacterial Agents ◽  
Antibacterial Chemotherapy

scholarly journals In VitroandIn VivoCharacterization of the Novel Oxabicyclooctane-Linked Bacterial Topoisomerase Inhibitor AM-8722, a Selective, Potent Inhibitor of Bacterial DNA Gyrase

2016 ◽  
Vol 60 (8) ◽  
pp. 4830-4839 ◽  
Author(s):  
Christopher M. Tan ◽  
Charles J. Gill ◽  
Jin Wu ◽  
Nathalie Toussaint ◽  
Jingjun Yin ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antibacterial Agents ◽  
Cell Activity ◽  
Dna Gyrase ◽  
Topoisomerase Iv ◽  
Bacterial Dna ◽  
Whole Cell ◽  
Content Type

ABSTRACTOxabicyclooctane-linked novel bacterial topoisomerase inhibitors (NBTIs) represent a new class of recently described antibacterial agents with broad-spectrum activity. NBTIs dually inhibit the clinically validated bacterial targets DNA gyrase and topoisomerase IV and have been shown to bind distinctly from known classes of antibacterial agents directed against these targets. Herein we report the molecular, cellular, andin vivocharacterization of AM-8722 as a representative N-alkylated-1,5-naphthyridone left-hand-side-substituted NBTI. Consistent with its mode of action, macromolecular labeling studies revealed a specific effect of AM-8722 to dose dependently inhibit bacterial DNA synthesis. AM-8722 displayed greater intrinsic enzymatic potency than levofloxacin versus both DNA gyrase and topoisomerase IV fromStaphylococcus aureusandEscherichia coliand displayed selectivity against human topoisomerase II. AM-8722 was rapidly bactericidal and exhibited whole-cell activity versus a range of Gram-negative and Gram-positive organisms, with no whole-cell potency shift due to the presence of DNA or human serum. Frequency-of-resistance studies demonstrated an acceptable rate of resistance emergencein vitroat concentrations 16- to 32-fold the MIC. AM-8722 displayed acceptable pharmacokinetic properties and was shown to be efficacious in mouse models of bacterial septicemia. Overall, AM-8722 is a selective and potent NBTI that displays broad-spectrum antimicrobial activityin vitroandin vivo.

Design, Synthesis, and Pharmacokinetic Evaluation of O-Carbamoyl Tizoxanide Prodrugs

2020 ◽  
Vol 16 ◽  
Author(s):  
Xi He ◽  
Wenjun Hu ◽  
Fanhua Meng ◽  
Xingzhou Li
Keyword(s):  
Plasma Concentration ◽  
Broad Spectrum ◽  
Plasma Concentrations ◽  
Antiviral Drug ◽  
Systemic Exposure ◽  
Pharmacokinetic Profile ◽  
Hydroxyl Group ◽  
First Pass

Background: The broad-spectrum antiparasitic drug nitazoxanide (N) has been repositioned as a broad-spectrum antiviral drug. Nitazoxanide’s in vivo antiviral activities are mainly attributed to its metabolitetizoxanide, the deacetylation product of nitazoxanide. In reference to the pharmacokinetic profile of nitazoxanide, we proposed the hypotheses that the low plasma concentrations and the low system exposure of tizoxanide after dosing with nitazoxanide result from significant first pass effects in the liver. It was thought that this may be due to the unstable acyloxy bond of nitazoxanide. Objective: Tizoxanide prodrugs, with the more stable formamyl substituent attached to the hydroxyl group rather than the acetyl group of nitazoxanide, were designed with the thought that they might be more stable in plasma. It was anticipated that these prodrugs might be less affected by the first pass effect, which would improve plasma concentrations and system exposure of tizoxanide. Method: These O-carbamoyl tizoxanide prodrugs were synthesized and evaluated in a mouse model for pharmacokinetic (PK) properties and in an in vitro model for plasma stabilities. Results: The results indicated that the plasma concentration and the systemic exposure of tizoxanide (T) after oral administration of O-carbamoyl tizoxanide prodrugs were much greater than that produced by equimolar dosage of nitazoxanide. It was also found that the plasma concentration and the systemic exposure of tizoxanide glucuronide (TG) were much lower than that produced by nitazoxanide. Conclusion: Further analysis showed that the suitable plasma stability of O-carbamoyl tizoxanide prodrugs is the key factor in maximizing the plasma concentration and the systemic exposure of the active ingredient tizoxanide.

scholarly journals Antibacterial Mechanisms and Efficacy of Sarecycline in Animal Models of Infection and Inflammation

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 439
Author(s):  
Christopher G. Bunick ◽  
Jonette Keri ◽  
S. Ken Tanaka ◽  
Nika Furey ◽  
Giovanni Damiani ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Bacterial Resistance ◽  
Antibiotic Use ◽  
In Vivo Studies ◽  
Infection Model ◽  
Severe Acne ◽  
Rat Paw Edema ◽  
Infection And Inflammation

Prolonged broad-spectrum antibiotic use is more likely to induce bacterial resistance and dysbiosis of skin and gut microflora. First and second-generation tetracycline-class antibiotics have similar broad-spectrum antibacterial activity. Targeted tetracycline-class antibiotics are needed to limit antimicrobial resistance and improve patient outcomes. Sarecycline is a narrow-spectrum, third-generation tetracycline-class antibiotic Food and Drug Administration (FDA)-approved for treating moderate-to-severe acne. In vitro studies demonstrated activity against clinically relevant Gram-positive bacteria but reduced activity against Gram-negative bacteria. Recent studies have provided insight into how the structure of sarecycline, with a unique C7 moiety, interacts with bacterial ribosomes to block translation and prevent antibiotic resistance. Sarecycline reduces Staphylococcus aureus DNA and protein synthesis with limited effects on RNA, lipid, and bacterial wall synthesis. In agreement with in vitro data, sarecycline demonstrated narrower-spectrum in vivo activity in murine models of infection, exhibiting activity against S. aureus, but reduced efficacy against Escherichia coli compared to doxycycline and minocycline. In a murine neutropenic thigh wound infection model, sarecycline was as effective as doxycycline against S. aureus. The anti-inflammatory activity of sarecycline was comparable to doxycycline and minocycline in a rat paw edema model. Here, we review the antibacterial mechanisms of sarecycline and report results of in vivo studies of infection and inflammation.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

scholarly journals Non-Toxic Virucidal Macromolecules Show High Efficacy Against Influenza Virus Ex Vivo and In Vivo

2020 ◽  
Author(s):  
Ozgun Kocabiyik ◽  
Valeria Cagno ◽  
Paulo Jacob Silva ◽  
Yong Zhu ◽  
Laura Sedano ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Viral Infections ◽  
Ex Vivo ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
New Class ◽  
Influenza Strain ◽  
Low Toxicity

AbstractInfluenza is one of the most widespread viral infections worldwide and represents a major public health problem. The risk that one of the next pandemics is caused by an influenza strain is very high. It is very important to develop broad-spectrum influenza antivirals to be ready for any possible vaccine shortcomings. Anti-influenza drugs are available but they are far from ideal. Arguably, an ideal antiviral should target conserved viral domains and be virucidal, i.e. irreversibly inhibit viral infectivity. Here, we describe a new class of broad-spectrum anti-influenza macromolecules that meets these criteria and displays exceedingly low toxicity. These compounds are based on a cyclodextrin core modified on its primary face with long hydrophobic linkers terminated in 6’sialyl-N-acetyllactosamine (6’SLN) or 3’SLN. SLN enables nanomolar inhibition of the viruses while the hydrophobic linkers confer irreversibility to the inhibition. The combination of these two properties allows for efficacy in vitro against several human or avian influenza strains, as well as against a 2009 pandemic influenza strain ex vivo. Importantly, we show that, in mice, the compounds provide therapeutic efficacy when administered 24h post-infection allowing 90% survival as opposed to no survival for the placebo and oseltamivir..

scholarly journals SCE-963, a New Broad-Spectrum Cephalosporin: In Vitro and In Vivo Antibacterial Activities

1978 ◽  
Vol 14 (4) ◽  
pp. 557-568 ◽  
Author(s):  
K. Tsuchiya ◽  
M. Kida ◽  
M. Kondo ◽  
H. Ono ◽  
M. Takeuchi ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antibacterial Activities

A review on Remdesivir: A broad-spectrum antiviral molecule for possible COVID-19 treatment

2021 ◽  
Vol 21 ◽  
Author(s):  
Jabeena Khazir ◽  
Tariq Maqbool ◽  
Bilal Ahmad Mir
Keyword(s):  
Clinical Trials ◽  
Broad Spectrum ◽  
Ebola Virus ◽  
Controlled Trial ◽  
In Vivo Studies ◽  
Therapeutic Drug ◽  
Viral Agent ◽  
Double Blind

: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus strain and the causative agent of COVID-19 was identified to have emerged in Wuhan, China, in December 2019 [1]. This pandemic situation and magnitude of suffering has led to global effort to find out effective measures for discovery of new specific drugs and vaccines to combat this deadly disease. In addition to many initiatives to develop vaccines for protective immunity against SARS-CoV-2, some of which are at various stages of clinical trials researchers worldwide are currently using available conventional therapeutic drugs with potential to combat the disease effectively in other viral infections and it is believed that these antiviral drugs could act as a promising immediate alternative. Remdesivir (RDV), a broad-spectrum anti-viral agent, initially developed for the treatment of Ebola virus (EBOV) and known to show promising efficiency in in vitro and in vivo studies against SARS and MERS coronaviruses, is now being investigated against SARS-CoV-2. On May 1, 2020, The U.S. Food and Drug Administration (FDA) granted Emergency Use Authorization (EUA) for RDV to treat COVID-19 patients [2]. A number of multicentre clinical trials are on-going to check the safety and efficacy of RDV for the treatment of COVID-19. Results of published double blind, and placebo-controlled trial on RDV against SARS-CoV-2, showed that RDV administration led to faster clinical improvement in severe COVID-19 patients compared to placebo. This review highlights the available knowledge about RDV as a therapeutic drug for coronaviruses and its preclinical and clinical trials against COVID-19.

scholarly journals A COMPARATIVE STUDY OF ANTIMICROBIAL PROFILE HAVING BROAD SPECTRUM BACTERIOCINS AGAINST ANTIBIOTICS

2017 ◽  
Vol 10 (9) ◽  
pp. 44 ◽  
Author(s):  
Sabiha Imran ◽  
Twinkle Gupta ◽  
Aarti Arora ◽  
Nilanjan Das
Keyword(s):  
Broad Spectrum ◽  
Cationic Peptides ◽  
Promising Alternative ◽  
Bacterial Diseases ◽  
Adverse Side Effects ◽  
Experimental Systems ◽  
Improper Use ◽  
Physical And Chemical

  Bacteriocins are ribosomally synthesized antimicrobial peptides produced by microbes owned by different eubacterial taxonomic branches. Most of them are small cationic membrane-active compounds that form pores in the targeted cells, disrupting membrane possibilities, and triggering cell fatality. The availability of small cationic peptides with antimicrobial activity is a protection strategy found not only in bacteria but also in plants and animals. The antibiotics which have extensive applications in the treatment of various bacterial diseases have developed alarming resistance against them in many pathogens due to improper use besides this antibiotics have adverse side effects also. There are an extensive variety of bacteriocins made by different bacterial genera have promising alternative to antibiotics that needs to be further studied to show the no existence of undesirable effects, which must be performed both in vitro and in vivo experimental systems. Most of the bacteriocin have narrow spectrum of their activity and effective only on the related species. There is an urgent need for the identification of broad-spectrum bacteriocins isolated from the species from different habitats that can be effective against both Gram-positive and Gram-negative pathogens. In this review, we focus on the main physical and chemical characteristics of broad-spectrum bacteriocin and discuss their application as an alternative option to antibiotics.

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