Antimicrobial peptides

Bovine mastitis is a frequent infection in lactating cattle, causing great economic losses. Staphylococcus aureus represents the main etiological agent, which causes recurrent and persistent intramammary infections because conventional antibiotics are ineffective against it. Mastoparan-like peptides are multifunctional molecules with broad antimicrobial potential, constituting an attractive alternative. Nevertheless, their toxicity to host cells has hindered their therapeutic application. Previously, our group engineered three mastoparan-L analogs, namely mastoparan-MO, mastoparan-R1, and [I5 , R8 ] MP, to improve cell selectivity and potential...

The nuclear factor binding the κ light chain in B-cells (NFκB) is involved in a wide range of cellular processes including development, growth, innate immunity, and sleep. However, genetic studies of the role of specific NFκB transcription factors in sleep have been limited. Drosophila fruit flies carry three genes encoding NFκB transcription factors, Dorsal, Dorsal Immunity Factor (Dif), and Relish. We previously found that loss of the Relish gene from fat body suppressed daily nighttime sleep, and abolished infection-induced sleep...

BACKGROUND: Diosmetin is an O-methylated flavone and the aglycone part of the flavonoid glycosides diosmin that occurs naturally in citrus fruits. Pharmacologically, diosmetin is reported to exhibit anticancer, antimicrobial, antioxidant, oestrogenic, and anti-inflammatory activities. OBJECTIVE: This comprehensive review was aimed to critically explore diverse pharmacological activities exhibited by diosmetin. Along with that, this review can also identify potential research areas with an elucidation of the multifactorial underlying signaling mechanism of action of diosmetin in different diseases...

Lactiplantibacillus plantarum BRD3A was isolated from Atingba, a traditional fermented rice-based beverage of Manipur. Its genomic sequence has 13 contigs and its genome size is 3,320,817 bp with a guanine-cytosine (GC) ratio of 44.6%. It comprises 3185 genes including 3112 coding sequences (CDSs), 73 RNAs (including 66 tRNAs and others), and one clustered regularly interspaced short palindromic repeat (CRISPR) array. A comparative and phylogenetic analysis with the Lp. plantarum genome shows that this strain has close similarity with other Lp...

OBJECTIVE: Today, designing nanofibers with antibacterial properties using electrospinning technology is one of the attractive approaches for wound healing. METHODS: & analysis : This study aims to fabricate a nanocomposite from polyethylene oxide (PEO) coated with copper nanoparticles (NPs) and defensin peptide with wound healing and antimicrobial properties in different ratios of CuNPs/defensin (2/0 mg), (1.5/0.5 mg), and (1/1 mg) in the fixed contain polymer (98 mg)...

The fig-milk dessert, a traditional and nutritionally rich treat infused with bioactive compounds, was subjected to a comprehensive analysis in this study. The novelty of this research lies in the investigation of the in vitro antioxidant, anticancer, and antimicrobial potential of the fig-milk dessert. This was accomplished through the utilization of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, Annexin/propidium iodide staining, microtiter plate-based assay and agar well diffusion, respectively, for the first time...

The interaction between pathogens and vectors' physiology can impact parasite transmission. Studying this interaction at the molecular level can help in developing control strategies. We study leishmaniases, diseases caused by Leishmania parasites transmitted by sand fly vectors, posing a significant global public health concern. Lipophosphoglycan (LPG), the major surface glycoconjugate of Leishmania, has been described to have several roles throughout the parasite's life cycle, both in the insect and vertebrate hosts...

Agricultural crops are targeted by various pathogens (fungi, bacteria, and viruses) and pests (herbivorous arthropods). Antimicrobial and insecticidal peptides are increasingly recognized as eco-friendly tools for crop protection due to their low propensity for resistance development and the fact that they are fully biodegradable. However, historical challenges have hindered their development, including poor stability, limited availability, reproducibility issues, high production costs, and unwanted toxicity...

Atopic dermatitis (AD) is a relapsing inflammatory skin condition that has become a global health issue with complex etiology and mounting prevalence. The association of AD with skin and gut microbiota has been revealed by virtue of the continuous development of sequencing technology and genomics analysis. Also, the gut-brain-skin axis and its mutual crosstalk mechanisms have been gradually verified. Accordingly, the microbiota-skin-gut axis also plays an important role in allergic skin inflammation. Herein, we reviewed the relationship between the microbiota-skin-gut axis and AD, explored the underlying signaling molecules and potential pathways, and focused on the potential mechanisms of probiotics, antimicrobial peptides (AMPs), coagulase-negative staphylococci transplantation, fecal microbiota transplantation, AMPs, and addition of essential fatty acids in alleviating AD, with the aim to provide a new perspective for targeting microbiota in the treatment of allergic skin inflammation...

BACKGROUND: This study addresses the urgent need for infection control agents driven by the rise of drug-resistant pathogens such as Acinetobacter baumannii. Our primary aim was to develop and assess a novel endolysin, Tha-PA90, designed to combat these challenges. METHODS: Tha-PA90 incorporates an antimicrobial peptide (AMP) called thanatin at its N-terminus, enhancing bacterial outer membrane permeability and reducing host immune responses. PA90 was selected as the endolysin component...

Bacterial resistance and excessive inflammation are common issues that hinder wound healing. Antimicrobial peptides (AMPs) offer a promising and versatile antibacterial option compared to traditional antibiotics, with additional anti-inflammatory properties. However, the applications of AMPs are limited by their antimicrobial effects and stability against bacterial degradation. TFNAs are regarded as a promising drug delivery platform that could enhance the antibacterial properties and stability of nanodrugs...

Cyclopeptides isolated from a variety of plants are a class of cyclic nitrogen-containing compounds, and they are primarily formed by peptide bonds between amino acids, generally containing 2 to 37 L-configuration encoded or non-encoded amino acid residues. Cyclopeptides have significant values in scientific research as natural small-molecule metabolites produced by plants. The available studies have revealed that such natural products are ubiquitous in plants, which mainly include cyclic dipeptides, cyclic tetrapeptides, cyclic pentapeptides, cyclic hexapeptides, cyclic heptapeptides, cyclic octapeptides, cyclic nonapeptides, and cyclic decapeptides...

Due to rapidly emerging resistance to single-site fungicides in fungal pathogens of plants, there is a burgeoning need for safe and multisite fungicides. Plant antifungal peptides with multisite modes of action (MoA) have potential as bioinspired fungicides. Medicago truncatula defensin MtDef4 was previously reported to exhibit potent antifungal activity against fungal pathogens. Its MoA involves plasma membrane disruption and binding to intracellular targets. However, specific biochemical processes inhibited by this defensin and causing cell death have not been determined...

Nanohydrogel wound healing refers to the use of nanotechnology-based hydrogel materials to promote the healing of wounds. Hydrogel dressings are made up of a three-dimensional network of hydrophilic polymers that can absorb and retain large amounts of water or other fluids. Nanohydrogels take this concept further by incorporating nanoscale particles or structures into the hydrogel matrix. These nanoparticles can be made of various materials, such as silver, zinc oxide, or nanoparticles derived from natural substances like chitosan...

Mycobacterium abscessus is increasingly recognized as an emerging opportunistic pathogen causing severe lung diseases and cutaneous infections. However, treatment of M. abscessus infections remains particularly challenging, largely due to intrinsic resistance to a wide panel of antimicrobial agents. New therapeutic alternatives are urgently needed. Herein, we show that, upon limited irradiation with a blue-light source, newly developed porphyrin-peptide cage-type photosensitizers exert a strong bactericidal activity against smooth and rough variants of M...

INTRODUCTION: Different active and passive strategies have been developed to fight against pathogenic bacteria. Those actions are undertaken to reduce the bacterial burden while minimizing the possibilities to develop not only antimicrobial resistance but also antimicrobial side-effects such as allergic or hypersensitivity reactions. AREAS COVERED: We have reviewed preclinical results that evidence that targeted antimicrobial therapies outperform non-targeted ones...

BACKGROUND: Vitamin D plays crucial roles in immune cell function, including macrophage activation, immune response modulation, and antimicrobial peptide production. Low vitamin D levels can result in reduced immune response, heightened inflammation, and impaired organ function, thereby exacerbating sepsis severity and impacting patient prognosis. This study investigates the influence of vitamin D binding protein expression and vitamin D levels on the mortality of septic patients. METHODS: This analytical observational study employs a case-control approach and involves patients at the Critical Care Unit of Dr...

The ability to sense and respond to host defenses is essential for pathogen survival. Some mechanisms involve two-component systems (TCS) that respond to host molecules, such as antimicrobial peptides (AMPs) and activate specific gene regulatory pathways to aid in survival. Alongside TCSs, bacteria coordinate cell division proteins, chaperones, cell wall sortases and secretory translocons at discrete locations within the cytoplasmic membrane, referred to as functional membrane microdomains (FMMs). In Group A Streptococcus (GAS), the FMM or "ExPortal" coordinates protein secretion, cell wall synthesis and sensing of AMP-mediated cell envelope stress via the LiaFSR three-component system...

Biofilms are complex communities of microorganisms enclosed in a self-produced extracellular matrix, posing a significant threat to different sectors, including healthcare and industry. This review provides an overview of the challenges faced due to biofilm formation and different novel strategies that can combat biofilm formation. Bacteria inside the biofilm exhibit increased resistance against different antimicrobial agents, including conventional antibiotics, which can lead to severe problems in livestock and animals, including humans...

INTRODUCTION: Various strategies have been researched to enhance the susceptibility of biofilms, given their tolerance to antibiotics. This study evaluated the effect of the antimicrobial peptide nisin in association with antibiotics used in regenerative endodontics, exploring different treatment times and biofilm growth conditions. METHODS: A mixture of ten bacterial species was cultivated on dentin specimens anaerobically for 21 days. Biofilms were treated with 1 mL of high-purity nisin Z (nisin ZP, 200 μg/mL) and a triple antibiotic mixture (TAP: ciprofloxacin + metronidazole + minocycline, 5mg/ mL), alone or in combination...