Linear and Polyvalent Peptides with Potent Antimicrobial Activity Against Sensitive and Multidrug-Resistant E. c oli Clinical Isolates.

Peptides containing the sequences RRWQWR and RRWQWRMKKLG derived from Bovine lactoferricin (LfcinB) were synthesized and their antibacterial effect against reference strains and sensitive and resistant clinical isolates of E. coli was evaluated. Tetra-branched multiple antigen peptide (MAP) ((RRWQWR)-K-Ahx-C) exhibited significant antibacterial activity against sensitive, resistant, and multidrug-resistant clinical isolates of E.

Antifungal Synergy: Mechanistic Insights into the R-1-R Peptide and Extract as Potent Therapeutics against spp. through Proteomics.

Previous reports have demonstrated that the peptide derived from LfcinB, R-1-R, exhibits anti- activity, which is enhanced when combined with an extract from the plant. However, the mechanism of action remains unexplored. In this research, a proteomic study was carried out, followed by a bioinformatic analysis and biological assays in both the SC5314 strain and a fluconazole-resistant isolate of after incubation with R-1-R.

Exploring the Potential Mechanism of Action of Piperine against and Targeting Its Virulence Factors.

Plant-derived compounds have proven to be a source of inspiration for new drugs. In this study, piperine isolated from the fruits of showed anti- activity. Furthermore, the mechanisms of action of piperine and its impact on virulence factors in , which have not been comprehensively understood, were also assessed.

Combining the Peptide RWQWRWQWR and an Ethanolic Extract of Enhances the Activity against Sensitive and Resistant and Strains.

The antifungal activity of palindromic peptide RWQWRWQWR and its derivatives was evaluated against clinical isolates of and . Also, ethanolic extracts of leaves and stem were evaluated. Furthermore, combinations of peptide, extract, and/or fluconazole (FLC) were evaluated.

Non-natural amino acids into LfcinB-derived peptides: effect in their (i) proteolytic degradation and (ii) cytotoxic activity against cancer cells.

The dimeric peptide [F]: (RRWQWRKKLG)-K-Ahx has exhibited a potent cytotoxic effect against breast cancer cell lines, with position 26 (F) being the most relevant for anti-cancer activity. In this investigation, six analogues of the [F] peptide were synthesized in which the 26th position was replaced by non-natural hydrophobic amino acids, finding that some modifications increased the resistance to proteolytic degradation exerted by trypsin or pepsin. Additionally, these modifications increased the cytotoxic effect against breast cancer cells and generated cell death mediated by apoptosis pathways, activating caspases 8 and 9, and did not compromise the integrity of the cytoplasmic membrane.

Proteomics and Genetic Approaches Elucidate the Circulation of Low Variability Staphylococcus aureus Strains on Colombian Dairy Farms.

Staphylococcus aureus is one of the most prevalent pathogens causing bovine mastitis in the world, in part because of its ease of adaptation to various hosts and the environment. This study aimed to determine the prevalence of S. aureus in Colombian dairy farms and its relationship with the causal network of subclinical mastitis.

Peptide-Resorcinarene Conjugates Obtained via Click Chemistry: Synthesis and Antimicrobial Activity.

Antimicrobial resistance (AMR) is one of the top ten threats to public health, as reported by the World Health Organization (WHO). One of the causes of the growing AMR problem is the lack of new therapies and/or treatment agents; consequently, many infectious diseases could become uncontrollable. The need to discover new antimicrobial agents that are alternatives to the existing ones and that allow mitigating this problem has increased, due to the rapid and global expansion of AMR.

The structure of associations: Method insights from analyzing 28 clinical isolates of Cryptococcus neoformans.

Clinical isolates of a fungal pathogen from a single region or country often exhibit structural clonality or phylogenetic clustering at the sequence or MLST level; such population structure can persist also in larger samples. In efforts to improve causal understanding of pathogenesis at the molecular level, genome-wide association screening methods initially designed for other kingdoms have been applied to fungi. The example of a Colombian dataset of 28 clinical Cryptococcus neoformans VNI isolates indicates where the output from standard pipelines may need to be analyzed in new ways in order to efficiently extract hypotheses for experiments from fungal genotype-phenotype data.

A Landscape of the Genomic Structure of in Colombian Isolates.

species complexes are recognized as environmental fungi responsible for lethal meningoencephalitis in immunocompromised individuals. Despite the vast knowledge about the epidemiology and genetic diversity of this fungus in different regions of the world, more studies are necessary to comprehend the genomic profiles across South America, including Colombia, considered to be the second country with the highest number of Cryptococcosis. Here, we sequenced and analyzed the genomic architecture of 29 Colombian isolates and evaluated the phylogenetic relationship of these strains with publicly available genomes.

Changes in Length and Positive Charge of Palindromic Sequence RWQWRWQWR Enhance Cytotoxic Activity against Breast Cancer Cell Lines.

Breast cancer is one of the main causes of premature death in women; current treatments have low selectivity, generating strong physical and psychological sequelae. The palindromic peptide R-1-R (RWQWRWQWR) has cytotoxic activity against different cell lines derived from cancer and selectivity against noncancerous cells. To determine if changes in the charge/length of this peptide increase its activity, six peptides were obtained by SPPS, three of them with addition of Arg at the N, C-terminal or both and three with deletion of Arg at the N, C-terminal or both.

In Vitro Antifungal Activity of Chimeric Peptides Derived from Bovine Lactoferricin and Buforin II against var. .

Cryptococcosis is associated with high rates of morbidity and mortality. The limited number of antifungal agents, their toxicity, and the difficulty of these molecules in crossing the blood-brain barrier have made the exploration of new therapeutic candidates against a priority task. To optimize the antimicrobial functionality and improve the physicochemical properties of AMPs, chemical strategies include combinations of peptide fragments into one.

Chimeric Peptides Derived from Bovine Lactoferricin and Buforin II: Antifungal Activity against Reference Strains and Clinical Isolates of spp.

Antimicrobial peptides (AMPs) are considered to be a valuable source for the identification and/or design of promising candidates for the development of antifungal treatments, since they have advantages such as lower tendency to induce resistance, ease of production, and high purity and safety. Bovine lactoferricin (LfcinB) and buforin II (BFII) are AMPs to which great antimicrobial potential has been attributed. The minimum motives with antimicrobial activity derived from LfcinB and BFII are RRWQWR and RLLR, respectively.

Evaluation of Anti- Potential of Extract in Inhibiting Growth, Yeast-Hyphal Transition, Virulent Enzymes, and Biofilm Formation.

Due to the increased incidence of fungal infections and the emergence of antifungal resistance mainly by species, the need for safe and effective novel therapies is imperative. Consequently, plants and herbs are a powerful source to combat infections. Here, we evaluated the anti- potential of an ethanolic extract from The phytochemical analysis of revealed bioactive compounds such as alkaloids, terpenoids, and tannis.

Deciphering the Association among Pathogenicity, Production and Polymorphisms of Capsule/Melanin in Clinical Isolates of var. VNI.

Background: is an opportunistic fungal pathogen that can cause meningitis in immunocompromised individuals. The objective of this work was to study the relationship between the phenotypes and genotypes of isolates of clinical origin from different cities in Colombia.

Methods: Genome classification of 29 clinical isolates of var.

Head-to-head comparison of CLSI, EUCAST, Etest and VITEK®2 results for Candida auris susceptibility testing.

The susceptibility of 31 Candida auris clinical isolates was evaluated by four methods, namely the microdilution reference method according to Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines as well as Etest and VITEK®2. Essential agreement between the two reference methods was 90%. Etest showed a better overall agreement with the reference methods (94% and 81% for CLSI and EUCAST, respectively) than VITEK®2 (70% and 72%, respectively).

The Combination of Iron and Copper Increases Pathogenicity and Induces Proteins Related to the Main Virulence Factors in Clinical Isolates of var. .

Unlabelled: In fungi, metals are associated with the expression of virulence factors. However, it is unclear whether the uptake of metals affects their pathogenicity. This study aimed to evaluate the effect of iron/copper in modulating pathogenicity and proteomic response in two clinical isolates of with high and low pathogenicity.

Designing Chimeric Peptides: A Powerful Tool for Enhancing Antibacterial Activity.

Chimeric peptides containing short sequences derived from bovine Lactoferricin (LfcinB) and Buforin II (BFII) were synthetized using solid-phase peptide synthesis (SPPS) and characterized via reversed-phase liquid chromatography and mass spectrometry. The chimeras were obtained with high purity, demonstrating their synthetic viability. The chimeras' antibacterial activity against Gram-positive and Gram-negative strains was evaluated.

Development and Validation of an Library of Colombian Strains with MALDI-TOF MS to Improve Yeast Identification.

Unlabelled: Background: is characterized for having a high genetic variability among species. MALDI-TOF MS library contains spectra from only three strains of , which makes difficult the identification process and gives low scores at the species level. Our aim was to construct and validate an internal library to improve identification with Colombian clinical strains.

as a Novelty Model of Host-Pathogen Interaction for CBS 1878 and CBS 1879.

and are lipophilic and lipid dependent yeasts, associated with the skin microbiota in humans and domestic animals, respectively. Although they are commensals, under specific conditions they become pathogens, causing skin conditions, such as pityriasis versicolor, dandruff/seborrheic dermatitis, folliculitis in humans, and dermatitis and otitis in dogs. Additionally, these species are associated with fungemia in immunocompromised patients and low-weight neonates in intensive care units with intravenous catheters or with parenteral nutrition and that are under-treatment of broad-spectrum antibiotics.

Selective cytotoxic effect against the MDA-MB-468 breast cancer cell line of the antibacterial palindromic peptide derived from bovine lactoferricin.

The cytotoxic effect against the breast cancer cell line MDA-MB-468 of the palindromic peptide LfcinB (21-25): RWQWRWQWR and its analogous peptides, obtained alanine scanning, was evaluated. The results indicate that the palindromic peptide exhibited a concentration-dependent cytotoxic effect against this cell line. The cytotoxic effect of the palindromic peptide was fast and selective and was sustained for up to 48 h of treatment.

Colonization by Pneumocystis jirovecii in patients with chronic obstructive pulmonary disease: association with exacerbations and lung function status.

Exposure to Pneumocystis jirovecii (P. jirovecii) can lead to a wide variety of presenting features ranging from colonization in immunocompetent patients with lung disease, to invasive infections in immunocompromised hosts. Colonization by this fungus in patients with chronic obstructive pulmonary disease (COPD) could be associated with higher rates of exacerbations and impaired lung function in these patients.

Genotypic Diversity Is Independent of Pathogenicity in Colombian Strains of and in .

Cryptococcosis is a potentially fatal opportunistic mycosis that affects the lungs and central nervous system. It has been suggested that certain strains of may have the potential to be more virulent according to the molecular type. This study aims to investigate the association between virulence in the model and genotypic diversity of Colombian clinical and environmental isolates of .

Candida albicans cell shaving uncovers new proteins involved in cell wall integrity, yeast to hypha transition, stress response and host-pathogen interaction.

The ability to switch from yeast to hyphal growth is essential for virulence in Candida albicans. The cell surface is the initial point of contact between the fungus and the host. In this work, a free-gel proteomic strategy based on tryptic digestion of live yeast and hyphae cells and protein identification using LC-MS/MS methodology was used to identify cell surface proteins.