AmpClass: an Antimicrobial Peptide Predictor Based on Supervised Machine Learning.

In the last decades, antibiotic resistance has been considered a severe problem worldwide. Antimicrobial peptides (AMPs) are molecules that have shown potential for the development of new drugs against antibiotic-resistant bacteria. Nowadays, medicinal drug researchers use supervised learning methods to screen new peptides with antimicrobial potency to save time and resources.

De novo design of short antimicrobial lipopeptides.

The increase in bacterial resistance to antibiotics available leads to the search for new compounds with antimicrobial potential, such as peptides and lipopeptides. In this work, eight short lipopeptides with the structural pattern Cn-X1 X2 X3-NH2 were de novo designed, synthesized by Fmoc solid phase and characterized by instrumental techniques. The results of the in vitro tests indicated that two of them, LIP 4 and LIP 12 display antibacterial activity against 4 pathogenic bacteria with minimum inhibitory concentrations (MIC) between 9.

Cytolytic activity of peptides derived from the Cry11Bb insecticidal toxin of B. thuringiensis subsp. medellin.

A few Bacillus thuringiensis Cry proteins, known as parasporins, have demonstrated cell proliferation inhibition of human cancer cells in vitro after protease activation. In this work, eight peptides derived from the Cry11Bb protoxin produced by B. thuringiensis subsp.

Design of antimicrobial and cytolytic peptides by computational analysis of bacterial, algal, and invertebrate proteomes.

The increase of antibiotic resistance in bacterial species has raised the need to search for novel antimicrobial molecules. Antimicrobial peptides are molecules that commonly display an amphipathic character. In this work, we developed a computational strategy to search for new peptide sequences within the proteome of any organism that includes in-house developed software and the use of artificial intelligence tools available online.

Toxic Activity, Molecular Modeling and Docking Simulations of Cry11 Toxin Variants Obtained via DNA Shuffling.

The Cry11 family belongs to a large group of δ-endotoxins that share three distinct structural domains. Among the dipteran-active toxins referred to as three-domain Cry11 toxins, the Cry11Aa protein from subsp. () has been the most extensively studied.

A case of incidental infection of Hepatitis E virus (HEV) genotype 1 in a domestic pig.

Hepatitis E virus (HEV) infection involving zoonotic genotypes is a public health problem in high-income and non-endemic developing countries. Herein we report the detection of a human genotype 1 (HEV-1) strain infecting a domestic pig, which is not considered a natural reservoir of this genotype. Viral load was quantified in stool by Real-Time qPCR and sequence analyses were performed.

In silico design of polycationic antimicrobial peptides active against Pseudomonas aeruginosa and Staphylococcus aureus.

Antimicrobial peptides (AMPs) have the potential to become valuable antimicrobial drugs in the coming years, since they offer wide spectrum of action, rapid bactericidal activity, and low probability for resistance development in comparison with traditional antibiotics. The search and improvement of methodologies for discovering new AMPs to treat resistant bacteria such as Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa are needed for further development of antimicrobial products. In this work, the software Peptide ID 1.

In-silico design and molecular docking evaluation of peptides derivatives from bacteriocins and porcine beta defensin-2 as inhibitors of Hepatitis E virus capsid protein.

Hepatitis E virus (HEV) is considered the main etiological agent that causes acute hepatitis. It is estimated that 20 million cases occur annually worldwide, reaching mortality rates of 28% in pregnant women. To date, available treatments and vaccines have not been entirely effective.

DNA secondary structure formation by DNA shuffling of the conserved domains of the Cry protein of .

Background: The Cry toxins, or δ-endotoxins, are a diverse group of proteins produced by . While DNA secondary structures are biologically relevant, it is unknown if such structures are formed in regions encoding conserved domains of Cry toxins under shuffling conditions. We analyzed 5 holotypes that encode Cry toxins and that grouped into 4 clusters according to their phylogenetic closeness.

InverPep: A database of invertebrate antimicrobial peptides.

Objectives: The aim of this work was to construct InverPep, a database specialised in experimentally validated antimicrobial peptides (AMPs) from invertebrates.

Methods: AMP data contained in InverPep were manually curated from other databases and the scientific literature. MySQL was integrated with the development platform Laravel; this framework allows to integrate programming in PHP with HTML and was used to design the InverPep web page's interface.

Enzymatic hydrolysis of molecules associated with bacterial quorum sensing using an acyl homoserine lactonase from a novel Bacillus thuringiensis strain.

N-acyl homoserine lactones are key components of quorum sensing, the bacterial communication system. This communication mechanism regulates the expression of genes, including those involved in virulence and biofilm formation. This system can be interrupted by the action of enzymes that hydrolyze the signaling molecules.

Electrical hypothesis of toxicity of the Cry toxins for mosquito larvae.

Many electrical properties of insect larval guts have been studied, but their importance for toxicity of the Cry-type toxins has never been reported in the literature. In the present work, we observed potential-dependent permeabilization of plasma membrane by several polycationic peptides derived from the Cry11Bb protoxin. The peptide BTM-P1d, all D-type amino acid analogue of the earlier reported peptide BTM-P1, demonstrated high membrane-permeabilizing activity in experiments with isolated rat liver mitochondria, RBC (red blood cells) and mitochondria in homogenates of Aedes aegypti larval guts.

Treatment of an Aedes aegypti colony with the Cry11Aa toxin for 54 generations results in the development of resistance.

To study the potential for the emergence of resistance in Aedes aegypti populations, a wild colony was subjected to selective pressure with Cry11Aa, one of four endotoxins that compose the Bacillus thuringiensis serovar israelensis toxin. This bacterium is the base component of the most important biopesticide used in the control of mosquitoes worldwide. After 54 generations of selection, significant resistance levels were observed.

Genetic and metabolic biodiversity of Trichoderma from Colombia and adjacent neotropic regions.

The genus Trichoderma has been studied for production of enzymes and other metabolites, as well as for exploitation as effective biological control agents. The biodiversity of Trichoderma has seen relatively limited study over much of the neotropical region. In the current study we assess the biodiversity of 183 isolates from Mexico, Guatemala, Panama, Ecuador, Peru, Brazil and Colombia, using morphological, metabolic and genetic approaches.

Potential-dependent permeabilization of plasma membrane by the peptide BTM-P1 derived from the Cry11Bb1 protoxin.

The peptide BTM-P1, which is derived from the amino acid sequence of the Cry11Bb1 protoxin, is able to permeabilize mitochondrial membranes and reveals antimicrobial activity. In this work we demonstrated that the permeabilizing activity of BTM-P1 for the plasma membrane of rat red blood cells increased in a dose-dependent manner for the concentration range of 1-4 microg/ml. Using osmotic protectants, the radius of pores formed at 4 microg/ml BTM-P1 was determined as 0.

Immigration of Bacillus thuringiensis to bean leaves from soil inoculum or distal plant parts.

Aims: We addressed the process of immigration of Bacillus thuringiensis from soil to leaves and its capacity to grow on bean diffusate medium (BDM), a medium designed to simulate the nutrient composition of the phylloplane.

Methods And Results: Two different B. thuringiensis strains were inoculated into soils, onto seeds or onto lower leaves of bean plants to determine if they were able to disperse to upper leaves under controlled conditions.

Modeling of growth and sporulation of Bacillus thuringiensis in an intermittent fed batch culture with total cell retention.

An extended dynamical model for growth and sporulation of Bacillus thuringiensis subsp. kurstaki in an intermittent fed-batch culture with total cell retention is proposed. This model differs from reported models, by including dynamics for natural death of cells and substrate consumption for cell maintenance.

B. thuringiensis is a poor colonist of leaf surfaces.

The ability of several Bacillus thuringiensis strains to colonize plant surfaces was assessed and compared with that of more common epiphytic bacteria. While all B. thuringiensis strains multiplied to some extent after inoculation on bean plants, their maximum epiphytic population sizes of 10(6) cfu/g of leaf were always much less than that achieved by other resident epiphytic bacteria or an epiphytically fit Pseudomonas fluorescens strain, which attained population sizes of about 10(7) cfu/g of leaf.

BTM-P1 polycationic peptide biological activity and 3D-dimensional structure.

The novel BTM-P1 peptide interferes with energetic processes in mitochondria; its antimicrobial activity against Gram-positive and Gram-negative bacteria is described here. BTM-P1 three-dimensional structure was determined by 1H NMR to explain its biological mechanisms and membrane activity. Structural data indicated that BTM-P1 can form an alpha-helix; circular dichroism analysis confirmed the peptide's propensity to behave as a typical transmembrane helix in a lipidic environment.

Diversity of Colombian strains of Bacillus thuringiensis with insecticidal activity against dipteran and lepidopteran insects.

Aim: To evaluate the genetic and molecular diversity and insecticidal activity of Bacillus thuringiensis isolates from all the natural regions of Colombia.

Methods And Results: A total of 445 isolates from a collection of B. thuringiensis were characterized.

Co-expression of the mosquitocidal toxins Cyt1Aa and Cry11Aa from Bacillus thuringiensis subsp. israelensis in Asticcacaulis excentricus.

The cyt1Aa gene from Bacillus thuringiensis subsp. israelensis (Bti), whose product synergizes other mosquitocidal toxins, and functions as a repressor of resistance developed by mosquitoes against Bacilli insecticides, was introduced into the aquatic Gram-negative bacterium Asticcacaulis excentricus alongside the cry11Aa gene. The genes were introduced as an operon, but although mRNA was detected for both genes, no Cyt1Aa toxin was detected.

Long-lasting effects of a Bacillus thuringiensis serovar israelensis experimental tablet formulation for Aedes aegypti (Diptera: Culicidae) control.

Dengue is a growing public health problem in many tropical and subtropical countries worldwide. At present, the only method of controlling or preventing the disease is to eliminate its vector, Aedes aegypti (L.) (Diptera: Culicidae).

Immune response in mice and cattle after immunization with a Boophilus microplus DNA vaccine containing bm86 gene.

Plasmid pBMC2 encoding antigen Bm86 from a Colombian strain of cattle tick Boophilus microplus, was used for DNA-mediated immunization of BALB/c mice, employing doses of 10 and 50microg, delivered by intradermic and intramuscular routes. Anti-Bm86 antibody levels were significantly higher compared to control mice treated with PBS. In the evaluation of immunoglobulin isotypes, significant levels of IgG2a and IgG2b were observed in mice immunized with 50microg of pBMC2.

Genetic variability of Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) populations from Latin America is associated with variations in susceptibility to Bacillus thuringiensis cry toxins.

Bacillus thuringiensis strains isolated from Latin American soil samples that showed toxicity against three Spodoptera frugiperda populations from different geographical areas (Mexico, Colombia, and Brazil) were characterized on the basis of their insecticidal activity, crystal morphology, sodium dodecyl sulfate-polyacrylamide gel electrophoresis of parasporal crystals, plasmid profiles, and cry gene content. We found that the different S. frugiperda populations display different susceptibilities to the selected B.