Marine Antimicrobial Peptides: Emerging Strategies Against Multidrug-Resistant and Biofilm-Forming Bacteria.

The global rise in antimicrobial resistance poses a major threat to public health, with multidrug-resistant bacterial infections expected to surpass cancer in mortality by 2050. As traditional antibiotic pipelines stagnate, novel therapeutic alternatives are critically needed. Antimicrobial peptides (AMPs), particularly those derived from marine organisms, have emerged as promising antimicrobial candidates due to their broad-spectrum activity, structural diversity, and distinctive mechanisms of action.

Hidden Allies: Decoding the Core Endohyphal Bacteriome of Aspergillus fumigatus.

Bacterial-fungal interactions that influence the behaviour of one or both organisms are common in nature. Well-studied systems include endosymbiotic relationships that range from transient to long-term associations. Diverse endohyphal bacteria associate with fungal hosts, emphasising the need to better comprehend the fungal bacteriome.

In Vivo Antimicrobial Activity of Nisin Z Against and Polyurea Pharmadendrimer PUREOEI Against from Diabetic Foot Infections.

Background/objectives: Diabetic foot infections (DFIs) are commonly associated with frequent hospitalizations, limb amputations, and premature death due to the profile of the bacteria infecting foot ulcers. DFIs are generally colonized by a polymicrobial net of bacteria that grows in biofilms, developing an increased antimicrobial resistance to multiple antibiotics. DFI treatment is a hurdle, and the need to develop new therapies that do not promote resistance is urgent.

Antibacterial Activity of ZnO Nanoparticles in a --Infected Model Is Tuned by Different Apple-Derived Phytocargos.

This research investigates pH changes during the green synthesis of ZnO nanoparticles (NPs) and emphasises its importance in their physicochemical, antibacterial, and biological properties. Varying the synthesis pH from 8 to 12 using "" apple extracts neither affected the morphology nor crystallinity of ZnO but impacted NP phytochemical loads. This difference is because alkaline hydrolysis of phytochemicals occurred with increasing pH, resulting in BE-ZnO with distinct phytocargos.

In-Silico Analysis Highlights the Existence in Members of Complex of a New Class of Adhesins Possessing Collagen-like Domains.

is a multi-drug-resistant lung pathogen. This species synthesizes various virulence factors, among which cell-surface components (adhesins) are critical for establishing the contact with host cells. This work in the first part focuses on the current knowledge about the adhesion molecules described in this species.

Increased Production of Pathogenic, Airborne Fungal Spores upon Exposure of a Soil Mycobiota to Chlorinated Aromatic Hydrocarbon Pollutants.

Organic pollutants are omnipresent and can penetrate all environmental niches. We evaluated the hypothesis that short-term (acute) exposure to aromatic hydrocarbon pollutants could increase the potential for fungal virulence. Specifically, we analyzed whether pentachlorophenol and triclosan pollution results in the production of airborne fungal spores with greater virulence than those derived from an unpolluted (Control) condition.

Effect of phage vB_EcoM_FJ1 on the reduction of ETEC O9:H9 infection in a neonatal pig cell line.

Enterotoxigenic Escherichia coli (ETEC) colonizes the intestine of young pigs causing severe diarrhoea and consequently bringing high production costs. The rise of antibiotic selective pressure together with ongoing limitations on their use, demands new strategies to tackle this pathology. The pertinence of using bacteriophages as an alternative is being explored, and in this work, the efficacy of phage vB_EcoM_FJ1 (FJ1) in reducing the load of ETEC EC43-Ph (serotype O9:H9 expressing the enterotoxin STa and two adhesins F5 and F41) was assessed.

Marine Sponge and Octocoral-Associated Bacteria Show Versatile Secondary Metabolite Biosynthesis Potential and Antimicrobial Activities against Human Pathogens.

Marine microbiomes are prolific sources of bioactive natural products of potential pharmaceutical value. This study inspected two culture collections comprising 919 host-associated marine bacteria belonging to 55 genera and several thus-far unclassified lineages to identify isolates with potentially rich secondary metabolism and antimicrobial activities. Seventy representative isolates had their genomes mined for secondary metabolite biosynthetic gene clusters (SM-BGCs) and were screened for antimicrobial activities against four pathogenic bacteria and five pathogenic strains.

Impact of Ca-Induced PI(4,5)P Clusters on PH-YFP Organization and Protein-Protein Interactions.

Despite its low abundance, phosphatidylinositol 4,5-bisphosphate (PI(4,5)P) is a key modulator of membrane-associated signaling events in eukaryotic cells. Temporal and spatial regulation of PI(4,5)P concentration can achieve localized increases in the levels of this lipid, which are crucial for the activation or recruitment of peripheral proteins to the plasma membrane. The recent observation of the dramatic impact of physiological divalent cation concentrations on PI(4,5)P clustering, suggests that protein anchoring to the plasma membrane through PI(4,5)P is likely not defined solely by a simple (monomeric PI(4,5)P)/(protein bound PI(4,5)P) equilibrium, but instead depends on complex protein interactions with PI(4,5)P clusters.

Core-shell polycationic polyurea pharmadendrimers: new-generation of sustainable broad-spectrum antibiotics and antifungals.

The efficacy of conventional antimicrobials is falling to critical levels and raising alarming concerns around the globe. In this scenery, engineered nanoparticles emerged as a solid strategy to fight growing deadly infections. Here, we show the and performance of pharmadendrimers, a novel class of engineered polyurea dendrimers that are synthetic mimics of antibacterial peptides, against a collection of both Gram-positive and Gram-negative bacteria and fungi.

Insights into the Antimicrobial Activities and Metabolomes of (, ) Species from the Rare Marine Biosphere.

Two novel natural products, the polyketide cuniculene and the peptide antibiotic aquimarin, were recently discovered from the marine bacterial genus Aquimarina. However, the diversity of the secondary metabolite biosynthetic gene clusters (SM-BGCs) in Aquimarina genomes indicates a far greater biosynthetic potential. In this study, nine representative Aquimarina strains were tested for antimicrobial activity against diverse human-pathogenic and marine microorganisms and subjected to metabolomic and genomic profiling.

Enhanced antibacterial activity of Rosehip extract-functionalized Mg(OH) nanoparticles: An in vitro and in vivo study.

The development of nanoparticles as antimicrobial agents against pathogenic bacteria has emerged as one of the leading global healthcare challenges. In this study, Mg(OH) NPs with controlled morphology and nanometric size, using two distinct counterions, chloride or nitrate, have been synthesized using Rosehip (RH) extract that has privileges beyond conventional chemical and physical methods. Various physicochemical techniques were used to characterize the RH-functionalized Mg-based NPs.

Cationic lipid-based formulations for encapsulation and delivery of anti-EFG1 2' OMethylRNA oligomer.

The effective protection and delivery of antisense oligomers to its site of action is a challenge without an optimal strategy. Some of the most promising approaches encompass the complexation of nucleic acids, which are anionic, with liposomes of fixed or ionizable cationic charge. Thus, the main purpose of this work was to study the complexation of cationic liposomes with anti-EFG1 2'OMe oligomers and evaluate the complex efficacy to control Candida albicans filamentation in vitro and in vivo using a Galleria mellonella model.

RNase R, a New Virulence Determinant of .

Pneumococcal infections have increasingly high mortality rates despite the availability of vaccines and antibiotics. Therefore, the identification of new virulence determinants and the understanding of the molecular mechanisms behind pathogenesis have become of paramount importance in the search of new targets for drug development. The exoribonuclease RNase R has been involved in virulence in a growing number of pathogens.

Third generation cephalosporin-resistant Klebsiella pneumoniae thriving in patients and in wastewater: what do they have in common?

Background: Klebsiella pneumoniae are ubiquitous bacteria and recognized multidrug-resistant opportunistic pathogens that can be released into the environment, mainly through sewage, where they can survive even after wastewater treatment. A major question is if once released into wastewater, the selection of lineages missing clinically-relevant traits may occur. Wastewater (n = 25) and clinical (n = 34) 3 generation cephalosporin-resistant K.

Anti- 2'-MethylRNA oligomer inhibits filamentation and attenuates the candidiasis in .

is a central transcriptional regulator of filamentation that is an important virulence factor of . This study serves to assess the applicability of the anti- 2'-MethylRNA oligomer for inhibiting filamentation and to attenuate candidiasis, using the model. For that, larvae infected with a lethal concentration of cells were treated with a single dose and with a double dose of the anti- 2'Me oligomer (at 40 and 100 nM).

Antisense locked nucleic acid gapmers to control Candida albicans filamentation.

Whereas locked nucleic acid (LNA) has been extensively used to control gene expression, it has never been exploited to control Candida virulence genes. Thus, the main goal of this work was to compare the efficacy of five different LNA-based antisense oligonucleotides (ASO) with respect to the ability to control EFG1 gene expression, to modulate filamentation and to reduce C. albicans virulence.

Burkholderia cenocepacia BCAM2418-induced antibody inhibits bacterial adhesion, confers protection to infection and enables identification of host glycans as adhesin targets.

Trimeric Autotransporter Adhesins (TAA) found in Gram-negative bacteria play a key role in virulence. This is the case of Burkholderia cepacia complex (Bcc), a group of related bacteria able to cause infections in patients with cystic fibrosis. These bacteria use TAAs, among other virulence factors, to bind to host protein receptors and their carbohydrate ligands.

Burkholderia cenocepacia transcriptome during the early contacts with giant plasma membrane vesicles derived from live bronchial epithelial cells.

Burkholderia cenocepacia is known for its capacity of adherence and interaction with the host, causing severe opportunistic lung infections in cystic fibrosis patients. In this work we produced Giant Plasma Membrane Vesicles (GPMVs) from a bronchial epithelial cell line and validated their use as a cell-like alternative to investigate the steps involved in the adhesion process of B. cenocepacia.

Role of CgTpo4 in Polyamine and Antimicrobial Peptide Resistance: Determining Virulence in .

is an emerging fungal pathogen whose success depends on its ability to resist antifungal drugs but also to thrive against host defenses. In this study, the predicted multidrug transporter CgTpo4 (encoded by ORF ) is described as a new determinant of virulence in , using the infection model . The gene was found to be required for the ability to kill .

Designing P. aeruginosa synthetic phages with reduced genomes.

In the era where antibiotic resistance is considered one of the major worldwide concerns, bacteriophages have emerged as a promising therapeutic approach to deal with this problem. Genetically engineered bacteriophages can enable enhanced anti-bacterial functionalities, but require cloning additional genes into the phage genomes, which might be challenging due to the DNA encapsulation capacity of a phage. To tackle this issue, we designed and assembled for the first time synthetic phages with smaller genomes by knocking out up to 48% of the genes encoding hypothetical proteins from the genome of the newly isolated Pseudomonas aeruginosa phage vB_PaeP_PE3.

Carbapenem-Resistant Clinical Isolates: In Vivo Virulence Assessment in and Potential Therapeutics by Polycationic Oligoethyleneimine.

, one of the most common pathogens found in hospital-acquired infections, is often resistant to multiple antibiotics. In fact, multidrug-resistant (MDR) producing KPC or OXA-48-like carbapenemases are recognized as a serious global health threat. In this sense, we evaluated the virulence of KPC(+) or OXA-48(+) aiming at potential antimicrobial therapeutics.

A new regulator in the crossroads of oxidative stress resistance and virulence in : The transcription factor CgTog1.

is a prominent pathogenic yeast which exhibits a unique ability to survive the harsh environment of host immune cells. In this study, we describe the role of the transcription factor encoded by the gene , here named CgTog1 after its ortholog, as a new determinant of virulence. Interestingly, Tog1 is absent in the other clinically relevant species (), being exclusive to .

Phenotypic characterization of trimeric autotransporter adhesin-defective bcaC mutant of Burkholderia cenocepacia: cross-talk towards the histidine kinase BCAM0218.

Burkholderia cenocepacia is a virulent species belonging to the Burkholderia cepacia complex (Bcc) and one of the most problematic agents of chronic lung infection in cystic fibrosis patients. B. cenocepacia possesses a large panel of virulence traits that include trimeric autotransporter adhesins (TAAs).

Antagonist biocompatibilities of Zn-based materials functionalized with physiological active metal oxides.

Zinc coated with nanostructured ZnO flowers has received increasing attention as a versatile biomaterial for medical applications. Whatsoever, the potential of these materials to meet specific medical requirements must be explored. Despite in its infancy, surface functionalization is the key strategy to achieve this goal.