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Background: Genus Bacillus is among the most widely studied bacteria used as probiotics in aquaculture. Besides its bioflocculant activity, it can offer other benefits, such as nitrogen recycling in the culture pond. Aim. To review the application of Bacillus in shrimp culture, particularly due to its bioflocculant effects on Biofloc systems. Development: Bacillus sp. produces a broad range of extracellular polymeric substances (EPS) and antimicrobial peptides against a variety of microorganisms, in addition to improving the immune response and growth of cultured animals and disease control. The bioflocculant potential of Bacillus species makes these bacteria good candidates for use in Penaeus vannamei cultures in Bioflock systems. Conclusions: However, new bioflocculant Bacillus strains must be isolated and characterized, along with an evaluation of the bioflocculant effect on Penaeus vannamei's metabolism and immune response. [ABSTRACT FROM AUTHOR]

Introduction: Actinobacteria, particularly Streptomyces species, have garnered significant attention in research due to their remarkable capacity to produce secondary metabolites through biosynthetic cluster gene (BCGs). These BCGs possess substantial medicinal potential on a global scale, especially in the post-Covid-19 era. Objective: This study aims to provide a comprehensive description of the latest and innovative bioactive peptides isolated from diverse species of the genus Streptomyces, highlighting their potential as candidates for the development of effective therapeutic drugs. Methodology: A literature search was conducted in the PubMed Central (PMC), ScienceDirect, ResearchGate, and Microbiology Society databases. Additionally, Research Rabbit, a bibliometric network software, focusing only on English-language publications between 2018 and 2023. The search terms employed included: Streptomyces, peptides, antimicrobial, antiviral, and antitumoral. Results: The findings of this state-of-the-art review present promising prospects for the vast array of substances derived from secondary metabolites produced by different species of Streptomyces, which hold potential for drug development. Noteworthy, compounds include antibacterial metabolites like gausemicin A-B and cadasides A-B, antiviral metabolites such as siamycin I and valinomycin, and taeanamides A-B and sungsanpin, exhibiting cytotoxicity against various tumor cell lines. Conclusion: Undoubtedly, Streptomyces is poised to play a pivotal role in combating drug resistance, given its extensive production of bioactive secondary metabolites, particularly antimicrobial peptides. These substances have demonstrated great promise as a compelling source for developing novel drugs targeting diverse microorganisms and relevant pathologies. [ABSTRACT FROM AUTHOR]

Cell cultures are a tool that allows the maintenance of cells in vitro preserving their physiological, biochemical and genetic characteristics to the maximum, which can present very diverse properties depending on the species, tissue of origin and the culture medium used. The use of dipteran cell cultures constitutes a valuable methodology in different disciplines, such as physiology, genetics, biochemistry and pathology; thus, for example, it has been possible to study various diseases of interest in both human and veterinary medicine. This review presents information on multiple cell lines of the order Diptera, which have been used to carry out studies of cell-cell interaction, intracellular flow of metabolites, production of bioinsecticides, viral amplification and production of antimicrobial peptides. In Colombia, 12 dipteran cell lines have been established, characterized and standardized, some of which have been used as substrates in studies of the biological cycle of parasites of the genus Leishmania, as well as in the evaluation of arbovirus susceptibility. In this trend, the information on cell lines derived from dipterans is analyzed and discussed in order to carry out this review of their characteristics and applications. [ABSTRACT FROM AUTHOR]

The article presents a literature review on the use of potato protein concentrate as an alternative to antibiotics in diets for weaned piglets. Possible alternatives are explored, such as antimicrobial peptides and plant-origin protease inhibitors, especially those derived from potatoes. Potato protein concentrate is highlighted as an ingredient with potential to be used in antibiotic-free diets, but more information is needed to verify its effectiveness. Additionally, potato proteins and their antimicrobial activity are mentioned, as well as studies showing improvements in productive performance and reduction of bacteria with the inclusion of potato protein in piglet diets. The use of chito-oligosaccharide as a substitute for growth promoters in weaned piglets is also analyzed. [Extracted from the article]

Introduction: Cnidarians depend on innate immunity for protection against both their own and external biological agents. It consists of three main immunological processes: 1) immune recognition, 2) intracellular signaling, and 3) effector response. Objective: To critically review current knowledge of the molecular repertoire involved in the immune response in cnidarians, its role in symbiosis, and possible biotechnological applications. Methods: We used keywords such as immunity, and immunological recognition in cnidarians, in the NCBI, Scielo and Google Scholar databases, for the last decade. Results: Cnidarian immune recognition consists of molecular pattern receptors and responses such as the mobilization of molecules to the site of infection, microbial ingestion, and the formation of molecules that activate signaling cascades. The signaling phase involves translation mediators that activate transcriptional genes and intracellular signaling cascades that initiate defenses. Effector responses include surface layer mucus, antimicrobial peptides, reactive oxygen species, and the cellular response mediated by phagocytosis. Conclusions: Immunity in Cnidaria is mediated by complex defense mechanisms composed of pathogen recognition receptors, intracellular signaling pathways, effector cells and molecules responsible for pathogen elimination, and recognition of symbionts. There is a potential for toxin compounds useful as antimicrobial molecules. [ABSTRACT FROM AUTHOR]

The review was elaborated to know the effect of fiber used as a prebiotic in broilers and laying hens. A review was made on the generalities of fiber and its benefits on immunity, digestive development, nutrient digestibility and productive performance. It was found that fiber as an additive can be included at levels lower than 3% to improve the immune response of the birds, increase the development of intestinal villi and the amount of cytokines that regulate chemotaxis, limiting the permeability of toxic substances to the bloodstream, and regulate the inflammatory response of the intestine. Fiber stimulates the intestinal microbiota by preventing the adherence and development of pathogenic bacteria, as well as the production of antimicrobial peptides. In addition, fiber can regulate intestinal motility, general microbiota, lipid accumulation in the liver, lower cholesterol, contribute to liver function, reduce pollutant emissions to the environment and improve nutrient absorption. Therefore, fiber can improve weight gain, feed conversion and gizzard muscle development. It is concluded that fiber as a prebiotic can be included in the poultry diet to replace synthetic additives to increase the productive performance of poultry. [ABSTRACT FROM AUTHOR]

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Escherichia coli O157: H7 is a pathogenic bacterium which is recognized for the ability to resist multiple antibiotics; accordingly, complications occur in the treatment of infections caused by this bacterium. The Ib-M1 peptide and the IONP @ Ib-M1 bioconjugate have emerged as a new antimicrobial alternatives against E. coli O157: H7. The mechanism of action of Ib-M1 and IONP @ Ib-M1 against this bacterium is still unknown; therefore, the goal of this research was to identify the change in the proteins profile of E. coli O157: H7 after treatment with Ib-M1 and IONP @ Ib-M1 as a first step to determine its mechanism of action. For this, the proteins were obtained first, and then a two-dimensional electrophoresis was performed to finally determine the variability of the protein profiles. Once the protein profiles were obtained, an analysis of variance (ANOVA) was carried out. 72 differentially expressed proteins were identified, which can be connected to the effect on the bacterium's growth in the presence of Ib-M1 and IONP @ Ib-M. These proteins are involved in acyl groups transfer processes (Yhbs protein), lipoprotein translocation (LolA protein) and amino acid transport (GpmA protein), among others. [ABSTRACT FROM AUTHOR]

Introduction: At the end of December 2019, a new coronavirus (SARS-CoV-2) was identified as the causative agent of a disease called COVID-19 by the World Health Organization. Objective: To describe the immunopathogenesis of COVID-19, as well as the pharmacological and toxicological aspects of the vaccine candidates. Methodological Design: A review of the main characteristics of SARS-CoV-2, morphology, structure, and mechanisms of entry and exit of the cell was carried out. Specific and non-specific immune responses were analyzed. Finally, an analysis of the pharmacological and toxicological aspects of the vaccine candidates used in the fight against COVID-19 was carried out. Conclusions: The invasion of the human body by the SARS-CoV-2 virus induces an immune response that may or may not be effective depending on internal factors or factors outside the host. The understanding of the immune response with the evaluation of the described cytokines may represent a useful scenario in the use of targets for effective therapies. Despite the advances in worldwide studies on the invasion mechanisms and defenses against SARS-CoV-2, there is still no effective therapy; other studies should be carried out that allow more effective directing of current treatments. In relation to this criterion, the pharmacological and toxicological aspects that the vaccine preparations could have on human health must be taken into account. [ABSTRACT FROM AUTHOR]

Microbial resistance has led to the search for innovative alternatives to contain it. One of the most promising ones is the use of peptides, not only due to their intrinsically antimicrobial characteristics, but also due to the synergistic and antagonistic interactions they present with other immunological mediators. These properties have enabled the creation of innate immune regulatory peptides, which represent a new immunomodulatory approach to treat infections. However, despite multiple attempts tested, only the designed with a high antimicrobial score have demonstrated effectiveness in phase three clinical trials. Yet, given their exceptionally wide spectrum of activity, a single peptide can have activity against Gram-negative bacterial, Gram-positive bacterial, fungi and even viruses and parasites, increasing the interest in researching these dynamic molecules. Furthermore, the CRISPR system enables the editing of bacterial genomes, which would make it posible to reduce their virulent activity and design antimicrobials based on programmable CRISPR-Cas 9 nucleases against specific targets. This system represent a promising path in the study of new alternatives with high potential to eliminate antibiotic resistance of highly pathogenic bacteria. Likewise, phage therapy, that is, the action of viruses that infect bacteria, used alone or in cocktails to increase their spectrum of action, taking advantage of their abundance in nature, given that it has been considered that each bacterium has a specific virus that it could be used as a potent antibacterial agent. Finally, as long as conventional antimicrobial treatments continue to be used used as the main means of containment, even when they are used correctly, the microevolution of bacteria will be itself sure to continue its own path. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lactic acid bacteria are known for their potential use in food preservation. Wild-type fruits of Ecuadorian Amazon tropical rainforest were used to isolate and identify new bacteriocinogenic lactic acid species. Among several isolates, Lactobacillus plantarum strain Gt4 (GenBank No. KY041689) showing highly inhibitory capacity was further characterized. Using agar-well diffusion assay, the crude-extract (CE) and precipitated bacteriocin (PP) derived from Gt4 strain displayed elevated antimicrobial activity towards several pathogenic bacteria. Its active principle was proteinaceous since the bacteriocin was inhibited by proteolytic enzymes and showed grater thermostability. Adsorption of the bacteriocin to pathogenic cells was increased when treated with EDTA, NaCl, Tween 20, at acidic pH and temperature of 37°C and 45°C. A decrease in adsorption was registered when cells were treated with SDS. Based on Tricine SDS-PAGE the estimated molecular weight was 10 kDa showing bactericidal mode of action. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (PAMs) play an important role in the innate defense systems of most organisms; they act against bacteria, fungi, viruses and parasites. The mechanism of action of cationic PAMs rely on their capacity to interact with the anionic microbial membrane surface. The cecropin family was identified as one of the most important peptides in insects. Such peptides do not contain cysteine residues and are classified as α-helical. To study the effect of the charge on the peptide structure, we introduced positive charge residues in the last 18 residues at the N-end of cecropin-D (WT) and evaluated the biological activity of the modified peptides. Two analogous peptides from cecropin-D were obtained by synthesis of a solid phase (SSP) with charges of +5 and +9. The analogous peptides were generated as followed: peptide +5 with three substitutions (E6R, E8R and Q12K) and peptide +9 with five substitutions (E1R, E6R, E8R, Q12K, and D16K). Antibacterial activity was evaluated to investigate the effects of the positive charge in these two analogue peptides against two groups of bacteria. The cationic peptides showed higher antimicrobial activity against Gram-negative and Gram-positive bacteria than the WT peptide. The 3D representations of the peptides showed that they have a-helical structure. Our results demonstrate that changes in the charge of peptides increase the antibacterial activity. [ABSTRACT FROM AUTHOR]

Treatment of bovine mastitis with antibiotic generates residues in milk that affects the quality of dairy products for the population feeding. The lactic acid bacteria have been proposed as an alternative to avoid use of antibiotics. The in vitro antimicrobial activity of six strains of Lactobacillus spp. was evaluated against bovine mastitis pathogens by diffusion on agar layers and disk diffusion of the supernatant. After neutralization with NaOH and heat (100 and 121°C for 5 min) and enzymatic treatments, the antagonistic activity of the cell-free supernatants of the three strains studied remained active. The inhibitory substances lactic acid (1.08 - 2.68 g.l-1) and hydrogen peroxide (0.05 - 0.26 g.l-1) were quantified. Four strains showed inhibitory potential against pathogenic strains of Staphylococcus spp. causing mastitis. The strain ML5 stood out for having greater inhibition halos (54-65 mm) against clinical isolates of pathogens such as Staphylococcus chromogenes and Staphylococcus hyicus, and, thus, showed to be a potential candidate to be evaluated in the prevention of bovine mastitis. [ABSTRACT FROM AUTHOR]

Copyright of FABICIB: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral is the property of Universidad Nacional del Litoral and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The great resistance to infectious process in skin is due, in part, to molecules named antimicrobial peptides (AMPs) that constitutes an important component responsible of mechanisms in innate immunity in this tissue. In this review the classification, structure and function of these molecules are shown, besides the information about the resistance mechanisms and their therapeutic potential. [ABSTRACT FROM AUTHOR]

The respiratory tract is one of the main apparatus which is in daily contact with a wide variety of microorganisms, however, only on a few occasions is infection establish because of its innate immune response. Respiratory tract epithelial cells play a very important role in avoiding infectious agent colonization of the lungs, since this kind of cell can recognize microbial molecules through very specialized receptors such as Toll-like. Moreover these cells posses a broad variety of molecules which are related to local immunity. Respiratory tract epithelial cells are capable of producing several chemokines, antimicrobial peptides and other pro-inflammatory molecules. [ABSTRACT FROM AUTHOR]

The article presents a study on the in vitro assay of the antimicrobial peptide melittin against different phytopathogenic bacteria. It is stated that the increasing resistance of plant-pathogenic bacteria and fungi to antibiotics and conventional pesticides has given way for the development of new compounds with novel targets of action. The aim of the study is to explore the advantages and limitations of the molecules of the peptides. Peptide melittin containing 26 amino acids was used to test the antibacterial properties against 39 strains belonging to plant pathogenic bacteria. Upon doing growth-inhibition assays, it was concluded that the degree of sensibility to melittin is a character showing a broad variation.