LAB Bacteriocins Controlling the Food Isolated (Drug-Resistant) Staphylococci

Staphylococci are a group of microorganisms that can be often found in processed food and theymight pose a risk for human health. In this study we have determined the content of staphylococci in 7 different fresh goat-milk cheeses. These bacteria were present in all of them, ranging from 103 to 106 CFU/g based on growth on selective media. Thus, a set of 97 colonies was randomly picked for phenotypic and genotypic identification. They could be clustered by RAPD-PCR in 10 genotypes, which were assigned by 16S rDNA sequencing to four Staphylococcus species: Staphylococcus aureus, Staphylococcus chromogenes, S. simulans, and S. xylosus. Representative strains of these species (n = 25) were tested for antibiotic sensitivity, and 11 of them were resistant to at least one of the antibiotics tested, including erythromycin, amoxicillin-clavulanic acid and oxacillin. We also tested two bacteriocins produced by lactic acid bacteria (LAB), namely the circular bacteriocin AS-48 and the lantibiotic nisin. These peptides have different mechanism of action at the membrane level. Nevertheless, both were able to inhibit staphylococci growth at low concentrations ranging between 0.16–0.73μM for AS-48 and 0.02–0.23μM for nisin, including the strains that displayed antibiotic resistance. The combined effect of these bacteriocins were tested and the fractional inhibitory concentration index (FICI) was calculated. Remarkably, upon combination, they were active at the low micromolar range with a significant reduction of the minimal inhibitory concentration. Our data confirms synergistic effect, either total or partial, between AS-48 and nisin for the control of staphylococci and including antibiotic resistant strains. Collectively, these results indicate that the combined use of AS-48 and nisin could help controlling (pathogenic) staphylococci in food processing and preventing antibiotic-resistant strains reaching the consumer in the final products.This research was funded by the Spanish Ministry of Economy and Competitiveness (SAF2013-48971-C2-1-R project), including funds from the European Regional Development Fundings (ERDF) and the Research Group General (BIO160, UGR

Embedding Biomimetic Magnetic Nanoparticles Coupled with Peptide AS-48 into PLGA to Treat Intracellular Pathogens

Among the strategies employed to overcome the development of multidrug-resistant bacteria, directed chemotherapy combined with local therapies (e.g., magnetic hyperthermia) has gained great interest. A nano-assembly coupling the antimicrobial peptide AS-48 to biomimetic magnetic nanoparticles (AS-48-BMNPs) was demonstrated to have potent bactericidal effects on both Gram-positive and Gram-negative bacteria when the antimicrobial activity of the peptide was combined with magnetic hyperthermia. Nevertheless, intracellular pathogens remain challenging due to the difficulty of the drug reaching the bacterium. Thus, improving the cellular uptake of the nanocarrier is crucial for the success of the treatment. In the present study, we demonstrate the embedding cellular uptake of the original nano-assembly into THP-1, reducing the toxicity of AS-48 toward healthy THP-1 cells. We optimized the design of PLGA[AS-48-BMNPs] in terms of size, colloidal stability, and hyperthermia activity (either magnetic or photothermal). The stability of the nano-formulation at physiological pH values was evaluated by studying the AS-48 release at this pH value. The influence of pH and hyperthermia on the AS-48 release from the nano-formulation was also studied. These results show a slower AS-48 release from PLGA[AS-48-BMNPs] compared to previous nano-formulations, which could make this new nano-formulation suitable for longer extended treatments of intracellular pathogens. PLGA[AS-48-BMNPs] are internalized in THP-1 cells where AS-48 is liberated slowly, which may be useful to treat diseases and prevent infection caused by intracellular pathogens. The treatment will be more efficient combined with hyperthermia or photothermia.FEDER Operational ProgramProyectos de I + D + I, del Plan Andaluz de Investigacion, Desarrollo e Innovacion B-BIO-432-UGR20 B-BIO-268-UGR20 B-CTS-216-UGR20 A-FQM-492-UGR20Instituto de Salud Carlos III European Commission P20-00346 P20_00339 P20-00233Spanish Government PI20-01658Federation of European Microbiological Societies (FEMS) EC2019-005930-P PDC2021-121135.100 FEMS-GO-2020-20

Beneficial Shifts in the Gut Bacterial Community of Gilthead Seabream (Sparus aurata) Juveniles Supplemented with Allium-Derived Compound Propyl Propane Thiosulfonate (PTSO)

This study analyzes the potential use of an Allium-derived compound, propyl propane thiosulfonate (PTSO), as a functional feed additive in aquaculture. Gilthead seabream (Sparus aurata) juveniles had their diet supplemented with this Allium-derived compound (150 mg/kg of PTSO) and were compared with control fish. The effects of this organosulfur compound were tested by measuring the body weight and analyzing the gut microbiota after 12 weeks. The relative abundance of potentially pathogenic Vibrio and Pseudomonas in the foregut and hindgut of supplemented fish significantly decreased, while potentially beneficial Lactobacillus increased compared to in the control fish. Shannon’s alpha diversity index significantly increased in both gut regions of fish fed with a PTSO-supplemented diet. Regarding beta diversity, significant differences between treatments only appeared in the hindgut when minority ASVs were taken into account. No differences occurred in body weight during the experiment. These results indicate that supplementing the diet with Allium-derived PTSO produced beneficial changes in the intestinal microbiota while maintaining the productive parameters of gilthead seabream juveniles.AQUAHEALTH project (Operational Programme Smart Growth 2014-2020) IDI-20170032FEDER-INNTERCONECTA-CDTI 2018, Centro para el Desarrollo Industrial, Spanish Ministry of Economy and Competitiveness ITC-20181099Programa Operativo de Empleo Juvenil (Fondo Social Europeo, Junta de Andalucia) 612

Allium-Based Phytobiotic Enhances Egg Production in Laying Hens through Microbial Composition Changes in Ileum and Cecum

The misuse of antibiotics has led several countries to ban their use as prophylactics against bacterial diseases or as growth promoters in livestock and poultry. Phytobiotics (bioactive compounds extracted from plants) are one of the alternatives, due to their antimicrobial activity and its modulation of the gut microbiota and the improvement of productive properties. Garlic and onion extracts, rich in antimicrobial compounds, are of the most promising alternative to antibiotics. We supplemented a garlic- and onion-based product in the diet to laying hens at the beginning of their productive life. The group supplied with this product produced in one month more eggs and with bigger size. This increase in production was accompanied by changes in the bacterial community of the gut. These changes in the microbiota suggest an improvement in food digestibility, as the most important changes produced by these compounds occur in the most distal parts of the gut. The relative abundance of beneficial Lactococcus in the ileum and Lactobacillus in the cecum increased in the experimental group. Both genera are known to have beneficial effects on host. These results are very promising for the use of these compounds in poultry for short periods.Phytobiotics (bioactive compounds extracted from plants) are one of the explored alternatives to antibiotics in poultry and livestock due to their antimicrobial activity and its positive effects on gut microbiota and productive properties. In this study, we supplemented a product based on garlic and onion compounds in the diet to laying hens at the beginning of their productive life (from 16 to 20 weeks post-hatching). The experimental group showed a significant increase in the number of eggs laid and in their size, produced in one month compared to the control. This increase in production was accompanied by microbiota changes in the ileum and cecum by means of high throughput sequencing analyses. These bacterial shifts in the ileum were mainly the result of compositional changes in the rare biosphere (unweighted UniFrac), while in the cecum, treatment affected both majority and minority bacterial groups (weighted and unweighted UniFrac). These changes in the microbiota suggest an improvement in food digestibility. The relative abundance of Lactococcus in the ileum and Lactobacillus in the cecum increased significantly in the experimental group. The relative abundance of these bacterial genera are known to have positive effects on thSpanish Ministry of Science and Innovation, Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía)University of Granada-CEI BioTic (Project No. P-BS-37)INTERCONECTA program (Spanish Ministry of Economy and Competitiveness

Preclinical studies of toxicity and safety of the AS-48 bacteriocin

The in vitro antimicrobial potency of the bacteriocin AS-48 is well documented, but its clinical application requires investigation, as its toxicity could be different in in vitro (haemolytic and antibacterial activity in blood and cytotoxicity towards normal human cell lines) and in vivo (e.g. mice and zebrafish embryos) models. Overall, the results obtained are promising. They reveal the negligible propensity of AS-48 to cause cell death or impede cell growth at therapeutic concentrations and support the suitability of this peptide as a potential therapeutic agent against several microbial infections, due to its selectivity and potency at low concentrations. In addition, AS-48 exhibits low haemolytic activity in whole blood and does not induce nitrite accumulation in non-stimulated RAW macrophages, indicating a lack of pro-inflammatory effects. The unexpected heightened sensitivity of zebrafish embryos to AS-48 could be due to the low differentiation state of these cells. The low cytotoxicity of AS-48, the absence of lymphocyte proliferation in vivo after skin sensitization in mice, and the lack of toxicity in a murine model support the consideration of the broad spectrum antimicrobial peptideThis research was funded by the Spanish Ministry of Economy and Competitiveness (SAF2013-48971-C2-1-R, CSD2010-00065, and AGL2015-67995-C3-3-R, all including funds from the European Regional Development Funding, ERDF) and by the Research Groups (BIO160, CTS 944 and CTS 164, UGR) from Junta de Andalucía (Spain). The CIBER-EHD is funded by the Instituto de Salud Carlos III. RM-E is grateful for an FPU Grant (FPU14/01537) from the Ministry of Education, (Spain)

Derecho, género e igualdad : cambios en las estructuras jurídicas androcéntricas. Vol I

Este libro es el resultado de trabajos seleccionados del I Congreso Internacional Derecho, Género e Igualdad, realizado en el año 2009 en la Universidad de Barcelona por el Grupo Antígona y el Grupo Dones i Drets

Factores que condicionan la resistencia a la supresividad de las estirpes rho- en saccharomyces cerevisiae

La supresividad de las estirpes rho- de saccharomyces cerevisiae que se viene definiendo como la propiedad que algunos mutantes rho- poseen para eliminar o excluir el factor rho normal de los zigotos aportado por la estirpe rho+ frente a la que se determina ha sido el objeto de este trabajo asi como el estudio de los factores que de alguna manera afectan a dicha supresividad tales como la estabilidad respiratoria que presentan las estirpes rho+ en relacin con la resistencia a la supresividad la influencia del genomio mitocondrial rho- y la formula adecuada para el clculo de la misma as como al estudio de la influencia que puedan ejercer factores de tipo ambientalUniversidad de Granada, Departamento de Microbiologa.Leida el 31- 01-7

Synergy of the Bacteriocin AS-48 and Antibiotics against Uropathogenic Enterococci

The genus Enterococcus comprises a ubiquitous group of Gram-positive bacteria that can cause diverse health care-associated infections. Their genome plasticity enables easy acquisition of virulence factors as well as antibiotic resistances. Urinary tract infections (UTIs) and catheter-associated UTIs are common diseases caused by enterococci. In this study, Enterococcus strains isolated from UTIs were characterized, showing that the majority were E. faecalis and contained several virulence factors associated to a better colonization of the urinary tract. Their susceptibility against the bacteriocin AS-48 and several antibiotics was tested. AS-48 is a potent circular bacteriocin that causes bacterial death by pore formation in the cell membrane. The interest of this bacteriocin is based on the potent inhibitory activity, the high stability against environmental conditions, and the low toxicity. AS-48 was active at concentrations below 10 mg/L even against antibiotic-resistant strains, whereas these strains showed resistance to, at least, seven of the 20 antibiotics tested. Moreover, the e ect of AS-48 combined with antibiotics commonly used to treat UTIs was largely synergistic (with up to 100-fold MIC reduction) and only occasionally additive. These data suggest AS-48 as a potential novel drug to deal with or prevent enterococcal infections.Spanish Ministry of Economy and Competitiveness SAF2013-48971-C2-1-REuropean Union (EU)Research Group General (UGR) BIO16

Allium Extract Implements Weaned Piglet’s Productive Parameters by Modulating Distal Gut Microbiota

Antimicrobial resistance (AMR) has risen as a global threat for human health. One of the leading factors for this emergence has been the massive use of antibiotics growth-promoter (AGPs) in livestock, enhancing the spread of AMR among human pathogenic bacteria. Thus, several alternatives such as probiotics, prebiotics, or phytobiotics have been proposed for using in animal feeding to maintain or improve productive levels while diminishing the negative effects of AGPs. Reducing the use of antibiotics is a key aspect in the pig rearing for production reasons, as well as for the production of high-quality pork, acceptable to consumers. Here we analyze the potential use of Allium extract as an alternative. In this study, weaned piglets were fed with Allium extract supplementation and compared with control and antibiotic (colistin and zinc oxide) treated piglets. The effects of Allium extract were tested by analyzing the gut microbiome and measuring different productive parameters. Alpha diversity indices decreased significantly in Allium extract group in caecum and colon. Regarding beta diversity, significant differences between treatments appeared only in caecum and colon. Allium extract and antibiotic piglets showed better values of body weight (BW), average daily weight gain (ADG), and feed conversion ratio (FCR) than control group. These results indicate that productive parameters can be implemented by modifying the gut microbiota through phytobiotics such as Allium extract, which will drive to drop the use of antibiotics in piglet die

Composición para el tratamiento de infecciones bacterianas de la piel y mucosas

Número de publicación: ES2387425 B2. Número de solicitud: 201231060.Composición para el tratamiento de infecciones bacterianas de la piel y mucosas.La presente invención se refiere a una composición para el tratamiento y la profilaxis de infecciones bacterianas de la piel que comprenden la bacteriocina AS-48 en combinación con lisozima. Más concretamente, se trata de composiciones con los principios activos disueltos en extractos adecuados para las aplicaciones frente Propionibacterium acnes y Staphylococcus aureus, de forma estabilizada en un preparado farmacéuticamente aceptable.Universidad de Granad