scholarly journals Deimmunized Lysostaphin Synergizes with Small-molecule Chemotherapies and Re-sensitizes MRSA to β-Lactam Antibiotics

2020 ◽  
pp. AAC.01707-20
Author(s):  
Yongliang Fang ◽  
Jack R. Kirsch ◽  
Liang Li ◽  
Seth A. Brooks ◽  
Spencer Heim ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Standard Of Care ◽  
Rapid Onset ◽  
Multidrug Resistant ◽  
Genetically Engineered ◽  
High Potency ◽  
Onset Of Action ◽  
New Antibiotics

There is an urgent need for novel agents to treat drug-resistant bacterial infections, such as multidrug-resistant Staphylococcus aureus (MRSA). Desirable properties for new antibiotics include high potency, narrow species selectivity, low propensity to elicit new resistance phenotypes, and synergy with standard of care (SOC) chemotherapies. Here, we describe analysis of the anti-MRSA potential exhibited by F12, an innovative anti-MRSA lysin that has been genetically engineered to evade detrimental antidrug immune responses in human patients. F12 possesses high potency and rapid onset of action, it has narrow selectivity against pathogenic Staphylococci, and it manifests synergy with numerous SOC antibiotics. Additionally, resistance to F12 and β-lactam antibiotics appears mutually exclusive, and importantly we provide evidence that F12 re-sensitizes normally resistant MRSA strains to β-lactams both in vitro and in vivo. These results suggest that combinations of F12 and SOC antibiotics could be a promising new approach to treating refractory S. aureus infections.

scholarly journals Evaluation of the Efficacy of a Bacteriophage in the Treatment of Pneumonia Induced by Multidrug ResistanceKlebsiella pneumoniaein Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Cao ◽  
Xitao Wang ◽  
Linhui Wang ◽  
Zhen Li ◽  
Jian Che ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Burst Size ◽  
Multidrug Resistant ◽  
Lung Lesion ◽  
Lytic Bacteriophage ◽  
Short Latent Period ◽  
Dose Dependent ◽  
Antibiotic Control

Multidrug-resistantKlebsiella pneumoniae(MRKP) has steadily grown beyond antibiotic control. However, a bacteriophage is considered to be a potential antibiotic alternative for treating bacterial infections. In this study, a lytic bacteriophage, phage 1513, was isolated using a clinical MRKP isolate KP 1513 as the host and was characterized. It produced a clear plaque with a halo and was classified as Siphoviridae. It had a short latent period of 30 min, a burst size of 264 and could inhibit KP 1513 growthin vitrowith a dose-dependent pattern. Intranasal administration of a single dose of 2 × 109 PFU/mouse 2 h after KP 1513 inoculation was able to protect mice against lethal pneumonia. In a sublethal pneumonia model, phage-treated mice exhibited a lower level ofK. pneumoniaeburden in the lungs as compared to the untreated control. These mice lost less body weight and exhibited lower levels of inflammatory cytokines in their lungs. Lung lesion conditions were obviously improved by phage therapy. Therefore, phage 1513 has a great effectin vitroandin vivo, which has potential to be used as an alternative to an antibiotic treatment of pneumonia that is caused by the multidrug-resistantK. pneumoniae.

scholarly journals Boromycin has Rapid-Onset Antibiotic Activity Against Asexual and Sexual Blood Stages of Plasmodium falciparum

2022 ◽  
Vol 11 ◽  
Author(s):  
Laís Pessanha de Carvalho ◽  
Sara Groeger-Otero ◽  
Andrea Kreidenweiss ◽  
Peter G. Kremsner ◽  
Benjamin Mordmüller ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Knowlesi ◽  
Rapid Onset ◽  
Multidrug Resistant ◽  
Antiplasmodial Activity ◽  
Onset Of Action ◽  
Streptomyces Antibioticus ◽  
Life Cycle Stages ◽  
Almost All

Boromycin is a boron-containing macrolide antibiotic produced by Streptomyces antibioticus with potent activity against certain viruses, Gram-positive bacteria and protozoan parasites. Most antimalarial antibiotics affect plasmodial organelles of prokaryotic origin and have a relatively slow onset of action. They are used for malaria prophylaxis and for the treatment of malaria when combined to a fast-acting drug. Despite the success of artemisinin combination therapies, the current gold standard treatment, new alternatives are constantly needed due to the ability of malaria parasites to become resistant to almost all drugs that are in heavy clinical use. In vitro antiplasmodial activity screens of tetracyclines (omadacycline, sarecycline, methacycline, demeclocycline, lymecycline, meclocycline), macrolides (oleandomycin, boromycin, josamycin, troleandomycin), and control drugs (chloroquine, clindamycin, doxycycline, minocycline, eravacycline) revealed boromycin as highly potent against Plasmodium falciparum and the zoonotic Plasmodium knowlesi. In contrast to tetracyclines, boromycin rapidly killed asexual stages of both Plasmodium species already at low concentrations (~ 1 nM) including multidrug resistant P. falciparum strains (Dd2, K1, 7G8). In addition, boromycin was active against P. falciparum stage V gametocytes at a low nanomolar range (IC50: 8.5 ± 3.6 nM). Assessment of the mode of action excluded the apicoplast as the main target. Although there was an ionophoric activity on potassium channels, the effect was too low to explain the drug´s antiplasmodial activity. Boromycin is a promising antimalarial candidate with activity against multiple life cycle stages of the parasite.

scholarly journals Clavanin A Improves Outcome of Complications from Different Bacterial Infections

2014 ◽  
Vol 59 (3) ◽  
pp. 1620-1626 ◽  
Author(s):  
Osmar N. Silva ◽  
Isabel C. M. Fensterseifer ◽  
Elaine A. Rodrigues ◽  
Hortência H. S. Holanda ◽  
Natasha R. F. Novaes ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Toxicity Tests ◽  
Cytotoxic Activities ◽  
Content Type ◽  
Wound Model ◽  
Acute Toxicity Tests

ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study, clavanin A, an antimicrobial peptide previously isolated from the marine tunicateStyela clava, was selected as a purposeful molecule that could be used in controlling infection and further synthesized. Clavanin A wasin vitroevaluated againstStaphylococcus aureusandEscherichia colias well as toward L929 mouse fibroblasts and skin primary cells (SPCs). Moreover, this peptide was challenged here in anin vivowound and sepsis model, and the immune response was also analyzed. Despite displaying clearin vitroantimicrobial activity toward Gram-positive and -negative bacteria, clavanin A showed no cytotoxic activities against mammalian cells, and in acute toxicity tests, no adverse reaction was observed at any of the concentrations. Moreover, clavanin A significantly reduced theS. aureusCFU in an experimental wound model. This peptide also reduced the mortality of mice infected withE. coliandS. aureusby 80% compared with that of control animals (treated with phosphate-buffered saline [PBS]): these data suggest that clavanin A prevents the start of sepsis and thereby reduces mortality. These data suggest that clavanin A is an AMP that could improve the development of novel peptide-based strategies for the treatment of wound and sepsis infections.

An Evaluation of Andursil – A New Antacid

1977 ◽  
Vol 5 (6) ◽  
pp. 99-104 ◽  
Author(s):  
G Beaumont ◽  
G I J Rigby ◽  
J Seldrup
Keyword(s):  
General Practitioner ◽  
Rapid Onset ◽  
Onset Of Action ◽  
Duration Of Effect ◽  
The Ideal

A number of characteristics of an ideal antacid are proposed. A new antacid formulation, Andursil, has been assessed both by in vitro and in vivo methods. Andursil has been found to compare favourably in its properties, with the profile of the ideal antacid. In a multicentre general practitioner trial it was found to be effective in relieving the symptoms of dyspepsia, to have a rapid onset of action and a satisfactory duration of effect, to be palatable and to be relatively free from undesirable effects.

An effective zinc phthalocyanine derivative against multidrug-resistant bacterial infection

2017 ◽  
Vol 21 (03) ◽  
pp. 205-210 ◽  
Author(s):  
Dong Wang ◽  
Yuxiang Zhang ◽  
Shufeng Yan ◽  
Zihan Chen ◽  
Yicai Deng ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Red Light ◽  
Multidrug Resistant ◽  
Zinc Phthalocyanine ◽  
In Vivo Studies ◽  
Infection Model ◽  
Clinical Test ◽  
Phthalocyanine Derivative

Bacterial skin and soft tissue infections are abundant worldwide. The rise in the incidence of multidrug-resistant (MDR) bacterial infections has made the need for alternative means of treatment more pressing. We herein report a zinc phthalocyanine derivative, pentalysine [Formula: see text]-carbonylphthalocyanine zinc (ZnPc-(Lys)[Formula: see text] and its strong capability of killing nosocomial MDR bacteria, including MDR-Escherichia coli and MDR-Acinetobacter baumannii. In vitro studies, we observed that ZnPc-(Lys)5 in micromolar concentrations killed above MDR bacteria in 6~6.5 log10 orders with only 5-min illumination of red light at a dosage of 12.75 J/cm[Formula: see text]. Further in vivo studies on a mouse infection model demonstrated that ZnPc-(Lys)5 efficiently inhibited the MDR bacterial growth after one-time photodynamic antibacterial therapy and, interestingly, significantly accelerated the wound healing. Putting together, our findings establish ZnPc-(Lys)5 as a potent antimicrobial candidate for the clinical test on localized infection.

Functional Nanomaterials for the Detection and Control of Bacterial Infections

2019 ◽  
Vol 19 (27) ◽  
pp. 2449-2475 ◽  
Author(s):  
Huiqiong Jia ◽  
Mohamed S. Draz ◽  
Zhi Ruan
Keyword(s):  
Bacterial Infections ◽  
Chemical Properties ◽  
Multidrug Resistant ◽  
Optimal Time ◽  
Resistant Bacteria ◽  
Functional Nanomaterials ◽  
Detection Techniques ◽  
Physical And Chemical

Infections with multidrug-resistant bacteria that are difficult to treat with commonly used antibiotics have spread globally, raising serious public health concerns. Conventional bacterial detection techniques are time-consuming, which may delay treatment for critically ill patients past the optimal time. There is an urgent need for rapid and sensitive diagnosis and effective treatments for multidrug-resistant pathogenic bacterial infections. Advances in nanotechnology have made it possible to design and build nanomaterials with therapeutic and diagnostic capabilities. Functional nanomaterials that can specifically interact with bacteria offer additional options for the diagnosis and treatment of infections due to their unique physical and chemical properties. Here, we summarize the recent advances related to the preparation of nanomaterials and their applications for the detection and treatment of bacterial infection. We pay particular attention to the toxicity of therapeutic nanoparticles based on both in vitro and in vivo assays. In addition, the major challenges that require further research and future perspectives are briefly discussed.

scholarly journals Fosfomycin

2016 ◽  
Vol 29 (2) ◽  
pp. 321-347 ◽  
Author(s):  
Matthew E. Falagas ◽  
Evridiki K. Vouloumanou ◽  
George Samonis ◽  
Konstantinos Z. Vardakas
Keyword(s):  
Bacterial Infections ◽  
Clinical Effectiveness ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Development Of Resistance ◽  
Extensively Drug Resistant ◽  
New Antibiotics

SUMMARYThe treatment of bacterial infections suffers from two major problems: spread of multidrug-resistant (MDR) or extensively drug-resistant (XDR) pathogens and lack of development of new antibiotics active against such MDR and XDR bacteria. As a result, physicians have turned to older antibiotics, such as polymyxins, tetracyclines, and aminoglycosides. Lately, due to development of resistance to these agents, fosfomycin has gained attention, as it has remained active against both Gram-positive and Gram-negative MDR and XDR bacteria. New data of higher quality have become available, and several issues were clarified further. In this review, we summarize the available fosfomycin data regarding pharmacokinetic and pharmacodynamic properties, thein vitroactivity against susceptible and antibiotic-resistant bacteria, mechanisms of resistance and development of resistance during treatment, synergy and antagonism with other antibiotics, clinical effectiveness, and adverse events. Issues that need to be studied further are also discussed.

scholarly journals Conjugative Delivery of CRISPR-Cas9 for the Selective Depletion of Antibiotic-Resistant Enterococci

2019 ◽  
Vol 63 (11) ◽  
Author(s):  
Marinelle Rodrigues ◽  
Sara W. McBride ◽  
Karthik Hullahalli ◽  
Kelli L. Palmer ◽  
Breck A. Duerkop
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Infections ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Conjugative Plasmid ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Resistance Determinants

ABSTRACT The innovation of new therapies to combat multidrug-resistant (MDR) bacteria is being outpaced by the continued rise of MDR bacterial infections. Of particular concern are hospital-acquired infections (HAIs) that are recalcitrant to antibiotic therapies. The Gram-positive intestinal pathobiont Enterococcus faecalis is associated with HAIs, and some strains are MDR. Therefore, novel strategies to control E. faecalis populations are needed. We previously characterized an E. faecalis type II CRISPR-Cas system and demonstrated its utility in the sequence-specific removal of antibiotic resistance determinants. Here, we present work describing the adaption of this CRISPR-Cas system into a constitutively expressed module encoded on a pheromone-responsive conjugative plasmid that efficiently transfers to E. faecalis for the selective removal of antibiotic resistance genes. Using in vitro competition assays, we show that these CRISPR-Cas-encoding delivery plasmids, or CRISPR-Cas antimicrobials, can reduce the occurrence of antibiotic resistance in enterococcal populations in a sequence-specific manner. Furthermore, we demonstrate that deployment of CRISPR-Cas antimicrobials in the murine intestine reduces the occurrence of antibiotic-resistant E. faecalis by several orders of magnitude. Finally, we show that E. faecalis donor strains harboring CRISPR-Cas antimicrobials are immune to uptake of antibiotic resistance determinants in vivo. Our results demonstrate that conjugative delivery of CRISPR-Cas antimicrobials may be adaptable for future deployment from probiotic bacteria for exact targeting of defined MDR bacteria or for precision engineering of polymicrobial communities in the mammalian intestine.

scholarly journals Formulation Development of Mouth Dissolving Film of Etoricoxib for Pain Management

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
K. Senthilkumar ◽  
C. Vijaya
Keyword(s):  
Pain Management ◽  
Immediate Release ◽  
Rapid Onset ◽  
Ease Of Use ◽  
Taste Masking ◽  
Formulation Development ◽  
Scanning Calorimetry ◽  
Onset Of Action

Etoricoxib is a potent, orally active, and highly selective COX-2 inhibitor that exhibits anti-inflammatory, analgesic, and antipyretic activities. The present research was undertaken to develop mouth dissolving films of etoricoxib to have rapid onset of action. Mouth dissolving film (MDF) is a better alternate to oral disintegrating tablets due to its novelty, ease of use, and the consequent patient compliance. Solubility enhancement and taste masking of etoricoxib were the two challenges solved by formulating drug-inclusion complex with beta-cyclodextrin (BCD). MDF prepared by solvent casting etoricoxib-BCD complex along with HPMC as film forming polymer was found to possess desirable physicomechanical properties. In vitro release of etoricoxib from MDF in simulated salivary fluid and 0.1 N HCl was more than 95% within 2 minutes. Taste masking and in vivo disintegration were in acceptable range as assessed by human volunteers. Etoricoxib MDF was further characterized by differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy. The index of analgesia shown by etoricoxib MDF was comparable to that of immediate release tablets (100% activity within 40 minutes) in animal studies. Conclusively, the present study documents the development of a commercially viable formula for an MDF of etoricoxib with rapidity in pain management.

scholarly journals Repurposing a peptide toxin from wasp venom into antiinfectives with dual antimicrobial and immunomodulatory properties

2020 ◽  
Vol 117 (43) ◽  
pp. 26936-26945
Author(s):  
Osmar N. Silva ◽  
Marcelo D. T. Torres ◽  
Jicong Cao ◽  
Elaine S. F. Alves ◽  
Leticia V. Rodrigues ◽  
...  
Keyword(s):  
Rational Design ◽  
Antibacterial Properties ◽  
Standard Of Care ◽  
Helical Structure ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Active Principle ◽  
Peptide Toxin

Novel antibiotics are urgently needed to combat multidrug-resistant pathogens. Venoms represent previously untapped sources of novel drugs. Here we repurposed mastoparan-L, the toxic active principle derived from the venom of the wasp Vespula lewisii, into synthetic antimicrobials. We engineered within its N terminus a motif conserved among natural peptides with potent immunomodulatory and antimicrobial activities. The resulting peptide, mast-MO, adopted an α-helical structure as determined by NMR, exhibited increased antibacterial properties comparable to standard-of-care antibiotics both in vitro and in vivo, and potentiated the activity of different classes of antibiotics. Mechanism-of-action studies revealed that mast-MO targets bacteria by rapidly permeabilizing their outer membrane. In animal models, the peptide displayed direct antimicrobial activity, led to enhanced ability to attract leukocytes to the infection site, and was able to control inflammation. Permutation studies depleted the remaining toxicity of mast-MO toward human cells, yielding derivatives with antiinfective activity in animals. We demonstrate a rational design strategy for repurposing venoms into promising antimicrobials.

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