scholarly journals Antibacterial Properties and Efficacy of a Novel SPLUNC1-Derived Antimicrobial Peptide, α4-Short, in a Murine Model of Respiratory Infection

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Shasha Jiang ◽  
Berthony Deslouches ◽  
Chen Chen ◽  
Matthew E. Di ◽  
Y. Peter Di
Keyword(s):  
Antimicrobial Peptides ◽  
Respiratory Infection ◽  
Broad Spectrum ◽  
Murine Model ◽  
White Blood Cells ◽  
Antibacterial Properties ◽  
Clinical Development ◽  
Health Crisis ◽  
Content Type

ABSTRACT Multidrug resistance (MDR) by bacterial pathogens constitutes a global health crisis, and resistance to treatment displayed by biofilm-associated infections (e.g., cystic fibrosis, surgical sites, and medical implants) only exacerbates a problem that is already difficult to overcome. Antimicrobial peptides (AMPs) are a promising class of therapeutics that may be useful in the battle against antibiotic resistance, although certain limitations have hindered their clinical development. The goal of this study was to examine the therapeutic potential of novel AMPs derived from the multifunctional respiratory host defense protein SPLUNC1. Using standard growth inhibition and antibiofilm assays, we demonstrated that a novel structurally optimized AMP, α4-short, was highly effective against the most common group of MDR bacteria while showing broad-spectrum bactericidal and antibiofilm activities. With negligible hemolysis and toxicity to white blood cells, the new peptide also demonstrated in vivo efficacy when delivered directly into the airway in a murine model of Pseudomonas aeruginosa-induced respiratory infection. The data warrant further exploration of SPLUNC1-derived AMPs with optimized structures to assess the potential application to difficult-to-cure biofilm-associated infections. IMPORTANCE The rise of superbugs underscores the urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs) have the ability to kill superbugs regardless of resistance to traditional antibiotics. However, AMPs often display a lack of efficacy in vivo. Sequence optimization and engineering are promising but may result in increased host toxicity. We report here the optimization of a novel AMP (α4-short) derived from the multifunctional respiratory protein SPLUNC1. The AMP α4-short demonstrated broad-spectrum activity against superbugs as well as in vivo efficacy in the P. aeruginosa pneumonia model. Further exploration for clinical development is warranted.

scholarly journals Engineered Cationic Antimicrobial Peptides (eCAPs) to Combat Multidrug-Resistant Bacteria

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 501 ◽  
Author(s):  
Berthony Deslouches ◽  
Ronald C. Montelaro ◽  
Ken L. Urish ◽  
Yuanpu P. Di
Keyword(s):  
Antimicrobial Peptides ◽  
De Novo ◽  
Multidrug Resistant ◽  
Clinical Development ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Health Crisis ◽  
Test Conditions ◽  
Reduced Activity

The increasing rate of antibiotic resistance constitutes a global health crisis. Antimicrobial peptides (AMPs) have the property to selectively kill bacteria regardless of resistance to traditional antibiotics. However, several challenges (e.g., reduced activity in the presence of serum and lack of efficacy in vivo) to clinical development need to be overcome. In the last two decades, we have addressed many of those challenges by engineering cationic AMPs de novo for optimization under test conditions that typically inhibit the activities of natural AMPs, including systemic efficacy. We reviewed some of the most promising data of the last two decades in the context of the advancement of the field of helical AMPs toward clinical development.

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.

scholarly journals Nanoparticles Enable Efficient Delivery of Antimicrobial Peptides for the Treatment of Deep Infections

2021 ◽  
Author(s):  
Yingxue Deng ◽  
Rui Huang ◽  
Songyin Huang ◽  
Menghua Xiong
Keyword(s):  
Antimicrobial Peptides ◽  
Broad Spectrum ◽  
Antimicrobial Properties ◽  
Therapeutic Index ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Efficient Delivery ◽  
Delivery Vehicles

Antimicrobial peptides (AMPs) have emerged as promising alternatives of traditional antibiotics against drug-resistant bacteria owing to their broad-spectrum antimicrobial properties and low tendency to drugresistance. However, their therapeutic efficacy in vivo, especially for infections in deep organs, is limited owing to their systemic toxicity and low bioavailability. Nanoparticles-based delivery systems offer a strategy to increase the therapeutic index of AMPs by preventing proteolysis, increasing the accumulation at infection sites, and reducing toxicity. Herein, we will discuss the current progress of using nanoparticles as delivery vehicles for AMPs for the treatment of deep infections.

scholarly journals Experimental Evolution In Vivo To Identify Selective Pressures during Pneumococcal Colonization

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Vaughn S. Cooper ◽  
Erin Honsa ◽  
Hannah Rowe ◽  
Christopher Deitrick ◽  
Amy R. Iverson ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Murine Model ◽  
Experimental Evolution ◽  
Nasal Colonization ◽  
Content Type ◽  
Selective Pressures ◽  
Specific Tissue ◽  
Tissue Tropisms ◽  
Insight Into

ABSTRACT Experimental evolution is a powerful technique to understand how populations evolve from selective pressures imparted by the surrounding environment. With the advancement of whole-population genomic sequencing, it is possible to identify and track multiple contending genotypes associated with adaptations to specific selective pressures. This approach has been used repeatedly with model species in vitro, but only rarely in vivo. Herein we report results of replicate experimentally evolved populations of Streptococcus pneumoniae propagated by repeated murine nasal colonization with the aim of identifying gene products under strong selection as well as the population genetic dynamics of infection cycles. Frameshift mutations in one gene, dltB, responsible for incorporation of d-alanine into teichoic acids on the bacterial surface, evolved repeatedly and swept to high frequency. Targeted deletions of dltB produced a fitness advantage during initial nasal colonization coupled with a corresponding fitness disadvantage in the lungs during pulmonary infection. The underlying mechanism behind the fitness trade-off between these two niches was found to be enhanced adherence to respiratory cells balanced by increased sensitivity to host-derived antimicrobial peptides, a finding recapitulated in the murine model. Additional mutations that are predicted to affect trace metal transport, central metabolism, and regulation of biofilm production and competence were also selected. These data indicate that experimental evolution can be applied to murine models of pathogenesis to gain insight into organism-specific tissue tropisms. IMPORTANCE Evolution is a powerful force that can be experimentally harnessed to gain insight into how populations evolve in response to selective pressures. Herein we tested the applicability of experimental evolutionary approaches to gain insight into how the major human pathogen Streptococcus pneumoniae responds to repeated colonization events using a murine model. These studies revealed the population dynamics of repeated colonization events and demonstrated that in vivo experimental evolution resulted in highly reproducible trajectories that reflect the environmental niche encountered during nasal colonization. Mutations impacting the surface charge of the bacteria were repeatedly selected during colonization and provided a fitness benefit in this niche that was counterbalanced by a corresponding fitness defect during lung infection. These data indicate that experimental evolution can be applied to models of pathogenesis to gain insight into organism-specific tissue tropisms.

Antimicrobial peptides in silkworm

2019 ◽  
Vol 69 (4) ◽  
pp. 391-410 ◽  
Author(s):  
Zhi Li ◽  
Yan Ma ◽  
Xuan Liu ◽  
Yi Li ◽  
Fangyin Dai
Keyword(s):  
Antioxidant Activity ◽  
Clinical Practice ◽  
Antimicrobial Peptides ◽  
Structure Function ◽  
Broad Spectrum ◽  
Antibacterial Properties ◽  
Antimicrobial Activities ◽  
Vital Role ◽  
Bacteria Resistance

Abstract Antimicrobial peptides (AMPs) are a type of small molecular proteins that play a vital role in the resistance to alien pathogens. AMPs are widespread in bacteria, archaea, protists, fungi, plants and animals. AMPs have a broad spectrum of antimicrobial activities and they rarely induce bacteria resistance; thus, they are thought to be good candidates for antibiotics in clinical practice. Recently, AMPs are increasingly attracting attention because of their outstanding features and functions. In addition to their known antibacterial properties, some kinds of AMPs have also been reported to have antiviral, anticancer, antiparasitic, and antioxidant activity. In this review, we introduce the diversity of AMPs, including their structure, function and related mechanisms. We focus primarily on recent studies of silkworm AMPs and summarize their classification, activities and possible mechanisms. Finally, based on the review, probable directions and perspectives for studies of the AMPs of silkworm are discussed and proposed.

scholarly journals Treatment of murine Candida krusei or Candida glabrata infection with L-743,872.

1997 ◽  
Vol 41 (9) ◽  
pp. 1937-1939 ◽  
Author(s):  
J R Graybill ◽  
R Bocanegra ◽  
M Luther ◽  
A Fothergill ◽  
M J Rinaldi
Keyword(s):  
Body Weight ◽  
Broad Spectrum ◽  
Candida Glabrata ◽  
Clinical Development ◽  
Candida Krusei ◽  
Murine Models ◽  
Fungal Cell ◽  
Significant Potential ◽  
Cell Counts

L-743,872 is a broad-spectrum pneumocandin antifungal drug developed by Merck Research Co., and in the present work it was evaluated in vivo in murine models of Candida krusei and Candida glabrata infection. Mice were infected intravenously with two isolates of C. krusei and treated with fluconazole or L-743,872. Fluconazole was beneficial only in immune-competent mice infected with isolate 94-2696. At > 0.5 mg/kg of body weight/day, L-743,872 was effective against both infecting isolates in immune-competent and immune-suppressed mice. Against C. glabrata, L-743,872 was effective, at doses > or = 0.5 mg/kg, in reducing fungal cell counts in the kidneys but not in the spleen. L-743,872 has significant potential for clinical development.

scholarly journals Efficacy of Bacteriophages in a Staphylococcus aureus Nondiabetic or Diabetic Foot Infection Murine Model

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
S. Albac ◽  
M. Medina ◽  
D. Labrousse ◽  
D. Hayez ◽  
D. Bonnot ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mouse Models ◽  
Murine Model ◽  
Phage Therapy ◽  
Single Injection ◽  
Antibacterial Efficacy ◽  
Content Type ◽  
Diabetic Foot Infection ◽  
Preclinical And Clinical Studies

ABSTRACT This study investigated the in vivo efficacy of three bacteriophages combined compared with linezolid in two mouse models (nondiabetic and diabetic) of Staphylococcus aureus foot infection. In both models, a single injection of bacteriophages in the hindpaw showed significant antibacterial efficacy. Linezolid was as effective as bacteriophages in nondiabetic animals but ineffective in diabetic animals. These findings further support preclinical and clinical studies for the development of phage therapy.

scholarly journals In Vivo Efficacy of Novel Monobactam LYS228 in Murine Models of Carbapenemase-Producing Klebsiella pneumoniae Infection

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
W. J. Weiss ◽  
M. E. Pulse ◽  
P. Nguyen ◽  
E. J. Growcott
Keyword(s):  
Klebsiella Pneumoniae ◽  
Clinical Development ◽  
Murine Models ◽  
Bacterial Burden ◽  
In Vivo Efficacy ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Infection Models ◽  
Resistant Strains

ABSTRACT LYS228 has potent antibacterial activity against carbapenem-resistant strains of Enterobacteriaceae. LYS228 was efficacious in neutropenic thigh models established with Klebsiella pneumoniae producing KPC-2 or NDM-1; pretreatment with uranyl nitrate considerably shifted calculated static doses of LYS228. In murine ascending pyelonephritis, LYS228 reduced bacterial burden in kidney, urine, and bladder. The successful treatment of murine infection models established with carbapenem-resistant K. pneumoniae further supports the clinical development of LYS228.

scholarly journals Efficacy of Humanized High-Dose Meropenem, Cefepime, and Levofloxacin against Enterobacteriaceae Isolates Producing Verona Integron-Encoded Metallo-β-Lactamase (VIM) in a Murine Thigh Infection Model

2015 ◽  
Vol 59 (11) ◽  
pp. 7145-7147 ◽  
Author(s):  
Islam M. Ghazi ◽  
Jared L. Crandon ◽  
Emil P. Lesho ◽  
Patrick McGann ◽  
David P. Nicolau
Keyword(s):  
Murine Model ◽  
Infection Model ◽  
High Dose ◽  
Content Type ◽  
High Mics

ABSTRACTWe aimed to describe thein vivoactivity of humanized pharmacokinetic exposures of meropenem and comparators against Verona integron-encoded metallo-β-lactamase (MBL) (VIM)-producingEnterobacteriaceaein a murine model. Levofloxacin activity was predicted by its MIC, and cefepime activity displayed variability, whereas meropenem produced a >1 log CFU reduction against all isolates despite high MICs indicative of resistance. Our results suggest that despitein vitroresistance, high-dose meropenem may be a possible option against infections caused byEnterobacteriaceaeproducing MBL-type carbapenemases.

scholarly journals Enantiomers of Nifurtimox Do Not Exhibit Stereoselective Anti-Trypanosoma cruzi Activity, Toxicity, or Pharmacokinetic Properties

2015 ◽  
Vol 59 (6) ◽  
pp. 3645-3647 ◽  
Author(s):  
Carolina B. Moraes ◽  
Karen L. White ◽  
Stéphanie Braillard ◽  
Catherine Perez ◽  
Junghyun Goo ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Murine Model ◽  
Therapeutic Benefit ◽  
Racemic Mixture ◽  
Content Type ◽  
Pharmacokinetic Properties

ABSTRACTWith the aim of improving the available drugs for the treatment of Chagas disease, individual enantiomers of nifurtimox were characterized. The results indicate that the enantiomers are equivalent in theirin vitroactivity against a panel ofTrypanosoma cruzistrains;in vivoefficacy in a murine model of Chagas disease;in vitrotoxicity and absorption, distribution, metabolism, and excretion characteristics; andin vivopharmacokinetic properties. There is unlikely to be any therapeutic benefit of an individual nifurtimox enantiomer over the racemic mixture.

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