Person: Bravo Vázquez, Daniel Antonio
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First Name
Daniel Antonio
Last Name
Bravo Vázquez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Biológicas
Department
Genética, Fisiología y Microbiología
Area
Microbiología
Identifiers
10 results
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Now showing 1 - 10 of 10
Item Combined Effect of High Pressure Processing with Enterocins or Thymol on the Inactivation of Listeria monocytogenes and the Characteristics of Sliced Dry-cured Ham(Food and Bioprocess Technology, 2018) Aida Pérez Baltar; Alejandro Serrano; Daniel Bravo; Raquel Montiel; Margarita Medina; Bravo Vázquez, Daniel AntonioThe effect of high pressure processing (HPP) at 450 MPa for 10 min, enterocins A and B, thymol, and their combinations on the inactivation of a four-strain cocktail of Listeria monocytogenes and the properties of sliced dry-cured ham during 30 days at 4 and 12 °C was investigated. Enterocins A and B initially reduced L. monocytogenes levels by more than 2.5 log units, but a regrowth was recorded during the storage. Individual treatments of thymol and HPP exhibited a low antimicrobial effect against the pathogen. A synergistic antibacterial activity against L. monocytogenes was observed when HPP was combined with enterocins A and B, preventing the recovery of the pathogen during all the storage period. Such combined treatment also maintained total viable counts (TVC) at low levels after 30 days at 4 and 12 °C. Minor changes were detected in pH, aw, color parameters, and shear strength values in dry-cured ham treated with enterocins A and B, thymol, HPP, and their combinations during the storage at both temperatures. Combination of HPP at 450 MPa for 10 min and enterocins A and B might be applied as a hurdle technology, since it reduced L. monocytogenes counts and spoilage bacteria, and slightly affected the characteristics of sliced dry-cured hamItem Cine en compañía para prevenir enfermedades(2023) Valderrama Conde, María José; Linares Gómez, María; Ayllón Santiago, Tania; De Francisco Martínez, Patricia; Bravo Vázquez, Daniel Antonio; López Ejeda, Noemí; Marrodán Serrano, María Dolores; Juan Chocano, María Del Carmen De; García Redondo, Alberto; Hernández Sánchez, María; López Vázquez de la Torre, Mª de la O ; Alonso Monge, Rebeca María Del Mar; Díez Orejas, Rosalía María; Navarro González De Mesa, Elisa; Ancos Pintado, Raquel ; Campo Moreno, Rosa del ; Rodríguez García, Alba ; García Vicente, Roberto ; Álvarez Sánchez-Redondo, Noemí ; Hernando Ospina, Natalia ; Rodríguez Solana, Patricia ; Pulido Vadillo, Mario ; León Rodríguez, Sergio ; Álvaro Llorente, Laura ; Pedrero Tomé, Roberto ; Alaminos Torres, AnaEl proyecto atiende la necesidad social de colectivos desfavorecidos o en riesgo de exclusión (sin hogar, presidiarios, discapacitados o enfermos mentales, mujeres) de ayuda al conocimiento sobre determinadas enfermedades que les afectan con una incidencia más alta que al resto de población (infecciosas, metabólicas, mentales, derivadas de consumo de drogas o alcohol o malnutrición). Adicionalmente, acusan carencias de compañía, entretenimiento o posibilidad de socialización, derivadas de sus circunstancias vitales. Los estudiantes que cursan titulaciones del ámbito de ciencias y ciencias de la salud profundizan en el aprendizaje de estas enfermedades realizando un servicio a estas personas de acompañamiento e información sobre prevención y/o tratamiento de las mismas. Trabajan en equipos multidisciplinares (distintas titulaciones y cursos) y desarrollan competencias profesionales en salud pública, así como transversales, como colaboración y coordinación en equipo, análisis crítico, expresión oral o diseño de materiales. Las actividades de servicio se llevan a cabo mediante visitas a los centros sociales asociados, donde se acompaña a los colectivos con proyección de películas sobre las enfermedades de interés, realización de juegos y coloquio. El proyecto comenzó en el curso 2017-18 (dentro de la convocatoria INNOVA) y ha ampliado el ámbito de conocimiento (bioquímica, biología molecular, epidemiología, microbiología, nutrición), facultades/organismos (Facultades de Biología, Farmacia, Medicina, Químicas, Hospitales 12 de Octubre y Ramón y Cajal), departamentos (Bioquímica y Biología molecular, Genética, Fisiología y Microbiología, Microbiología y Parasitología, Biodiversidad, Ecología y Evolución), asignaturas / titulaciones de los estudiantes, tipo de enfermedades abordadas y grupos y centros sociales atendido (distintas entidades y Ayuntamiento de Madrid).Item Phytoestrogen metabolism by lactic acid bacteria: Enterolignan production by Lactobacillus salivarius and Lactobacillus gasseri strains(Journal of Functional Foods, 2017) Ángela Peirotén; Inmaculada Álvarez; José Mª Landete.; Bravo Vázquez, Daniel AntonioPhytoestrogens are plant polyphenols similar to human estrogens. Isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria into equol, urolithins, and enterolignans, respectively, which are more bioavailable and bioactive, having beneficial effects on health. In this paper, we analysed the production of equol, 5-hydroxy-equol, enterodiol and enterolactone by 70 strains of Lactobacillus, Lactococcus and Enterococcus. Enterodiol and enterolactone production was found in Lactobacillus salivarius INIA P183, Lb. salivarius INIA P448 and Lactobacillus gasseri INIA P508, in levels around 46 mM and 6 mM respectively. However, we did not find neither equol nor 5-hydroxy-equol producing strains. Furthermore, analysis of the ellagic acid metabolism was extended to a total of 138 lactic acid bacteria strains, although none of them produced urolithins. This is the first time that simultaneous production of enterolactone and enterodiol is described in bacteria with probiotic potential, open their possible application in functional foods.Item Inactivation of Listeria monocytogenes during dry-cured ham processing.(International Journal of Food Microbiology, 2019) Montiel, Raquel; Peirotén, Ángela; Gaya, Pilar; Martinez-Suarez, Joaquín V.; Tapiador, Julio; Núñez, Manuel; Medina, Margarita; Bravo Vázquez, Daniel Antonio; Ortiz, Sagrario; ElsevierThe effect of Serrano and Iberian dry-cured ham processing and ripening on Listeria monocytogenes inactivation at the surface of whole hams was investigated. Salted hams were surface inoculated (6.5 log CFU) with a cocktail of 4 L. monocytogenes strains isolated from environment and products of a meat industry. Serrano and Iberian hams were ripened for 16 and 24 months, respectively. A decrease of at least 4.6 log units on the surface of Serrano ham was recorded after 4 months for L. monocytogenes counts, which remained under the detection limit thereafter. L. monocytogenes declined by >5 log units on the surface of Iberian ham during the first 9 months and was not detected afterwards. The higher nitrite content of Serrano ham might have accelerated the decrease of the pathogen. This study validates the inactivation of L. monocytogenes on the surface of whole dry-hams during extended ripening.Item Bile-induced promoters for gene expression in Lactobacillus strains(Applied genetics and molecular biotechnology, 2019) José Alberto Martínez Fernández; Ángela Peirotén; José María Landete; Bravo Vázquez, Daniel Antonio; Arqués Orobón, Juan LuisBioengineering of probiotics allows the improvement of their beneficial characteristics. In this work, we develop a molecular tool that would allow the activation of desirable traits in probiotics once they reach the intestine. The activity of upstream regions of bile-inducible genes of Lactobacillus casei BL23 and Lactobacillus plantarum WCFS1 was analyzed using plasmids encoding an anaerobic fluorescent protein as reporter. The promoter P16090 from Lb. casei BL23 was selected and its bile induction confirmed in Lb. casei BL23, Lb. plantarum WCFS1, and in Lactobacillus rhamnosus and Lactobacillus reuteri strains. However, the induction did not occur in Lactococcus lactis MG1363 or Bifidobacterium strains. Studies with different bile compounds revealed the importance of cholic acid in the bile induction process. Induction of fluorescence was also confirmed for transformed Lb. casei BL23 under simulated colonic conditions and in the presence of intestinal microbiota. The developed vector, pNZ:16090-aFP, constitutes a promising tool suitable for the expression of genes of interest under intestinal conditions in probiotic strains of the species Lb. casei, Lb. plantarum, Lb. rhamnosus, and Lb. reuteri.Item Bacterial metabolism as responsible of beneficial effects of phytoestrogens on human health(Critical Reviews in Food Science and Nutrition, 2019) Bravo Vázquez, Daniel Antonio; Peirotén, Ángela; Landete, José María; Taylor & FrancisPhytoestrogens (PE) are compounds found in plants such as soy (isoflavones), flax seeds and cereals (lignans) and pomegranates (ellagitannins). PE have shown estrogenic/antiestrogenic, antioxidant, anti-inflammatory, antineoplastic and apoptotic activities. The human studies are showing promising although inconsistent results about the beneficial effects of PE on ameliorating the menopausal symptoms or reducing the risk of certain cancers, cardiovascular disease or diabetes. The effects of PE on the organism are mediated by the intestinal microbiota, which transforms them into bioactive PE such as genistein, equol, enterolignans and certain urolithins. In this work, we review the most recent findings about the bacteria able to metabolize PE, together with the latest studies on the effects of PE on health. In addition, we describe the possible factors hindering the demonstration of the beneficial effect of PE on health, evincing the importance of measuring the actual circulating PE in order to encompass the variability of PE metabolism due to the intestinal microbiota. With this in mind, we also explore an approach to ensure the access to bioactive PE.Item Microcins, peptide antimicrobials from Enterobacterales in the eco-active intestinal chemosphere(Frontiers in Microbiology, 2019) Baquero, Fernando; Fernández. V F.; Baquero, María Rosario; Del Campo, Rosa; Bravo Vázquez, Daniel AntonioMicrocins are low-molecular-weight, ribosomally produced, highly stable, bacterial-inhibitory molecules involved in competitive, and amensalistic interactions between Enterobacteriaceae in the intestine. These interactions take place in a highly complex chemical landscape, the intestinal eco-active chemosphere, composed of chemical substances that positively or negatively influence bacterial growth, including those originated from nutrient uptake, and those produced by the action of the human or animal host and the intestinal microbiome. The contribution of bacteria results from their effect on the host generated molecules, on food and digested food, and organic substances from microbial origin, including from bacterial degradation. Here, we comprehensively review the main chemical substances present in the human intestinal chemosphere, particularly of those having inhibitory effects on microorganisms. With this background, and focusing on Enterobacteriaceae, the most relevant human pathogens from the intestinal microbiota, the microcin’s history and classification, mechanisms of action, and mechanisms involved in microcin’s immunity (in microcin producers) and resistance (non-producers) are reviewed. Products from the chemosphere likely modulate the ecological effects of microcin activity. Several cross-resistance mechanisms are shared by microcins, colicins, bacteriophages, and some conventional antibiotics, which are expected to produce cross-effects. Double-microcin-producing strains (such as microcins MccM and MccH47) have been successfully used for decades in the control of pathogenic gut organisms. Microcins are associated with successful gut colonization, facilitating translocation and invasion, leading to bacteremia, and urinary tract infections. In fact, Escherichia coli strains from the more invasive phylogroups (e.g., B2) are frequently microcinogenic. A publicly accessible APD3 database http://aps.unmc.edu/AP/ shows particular genes encoding microcins in 34.1% of E. coli strains (mostly MccV, MccM, MccH47, and MccI47), and much less in Shigella and Salmonella (<2%). Some 4.65% of Klebsiella pneumoniae are microcinogenic (mostly with MccE492), and even less in Enterobacter or Citrobacter (mostly MccS). The high frequency and variety of microcins in some Enterobacteriaceae indicate key ecological functions, a notion supported by their dominance in the intestinal microbiota of biosynthetic gene clusters involved in the synthesis of post-translationally modified peptide microcins.Item Genetic engineering as a powerful tool to improve probiotic strains(Biotechnology and Genetic Engineering Reviews, 2017) José M Landete; Bravo Vázquez, Daniel AntonioOver the last decade, there has been increasing interest in the use of probiotic microorganisms. However, certain doubts have arisen around probiotics, because of the beneficial effects of these microorganisms are not clear yet, and in many occasions those beneficial effects have not been proven. Therefore, it would be of interest if these probiotic strains were able to acquire new attributes to allow them improve and increase their beneficial characteristics. Genetic engineering can be used for human applications; for instance, the resistance to antibiotics is removed and the probiotic bacteria are modified in its own DNA. This process can be achieved by (1) the use of food-grade vectors derived from lactic acid bacteria and/or bifidobacteria cryptic plasmids, (2) the genes integration or deletion in the chromosome of the probiotic strain, by site-specific recombination using the attP/integrase system, or by homologous recombination, using either suicide vectors, (3) using the clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated (Cas) nuclease. Through genetic engineering, the knowledge of probiotic strains as well as its use could be improved, and the doubts about probiotics could be crumpedItem Influence of different lignan compounds on enterolignan production by Bifidobacterium and Lactobacillus strains(International Journal of Food Microbiology, 2018) Bravo Vázquez, Daniel Antonio; Peroitén, A.; Gaya, P.; Álvarez, I.; Landete, J.MEnterolignans, i.e. enterodiol and enterolactone, are polyphenols derived from the microbial metabolism of dietary lignans. They are considered phytoestrogens because of their estrogenic/antiestrogenic activity, which confers them benefits to human health when they reach sufficient levels in plasma. Hence, there is a great interest in studying the bacteria involved in enterolignan production. In the present study, three bifidobacterial strains (Bifidobacterium bifidum INIA P466, Bifidobacterium catenulatum INIA P732 and Bifidobacterium pseudolongum INIA P2) were found capable of producing low levels of enterodiol (2–11 μM) from lignan extracts; while another one (Bifidobacterium pseudocatenulatum INIA P946) was found to produce an important increment of the lignan secoisolariciresinol (SECO). Subsequently, the three enterodiol-producing bifidobacteria and another three Lactobacillus strains previously identified as enterolignans producers (Lactobacillus gasseri INIA P508, Lactobacillus salivarius INIA P448 and Lb. salivarius INIA P183), were tested on pure lignans yielding both enterodiol and enterolactone from secoisolariciresinol (SECO), while they did not metabolised the other lignan tested (i.e. matairesinol). B. catenulatum INIA P732 and Lb. gasseri INIA P508 were the strains that transformed the greatest percentage of SECO, yielding enterolactone concentrations above 2 mM. In addition, the formation of the intermediate compound dihydroxyenterodiol was observed as part of SECO transformation by all the strains. In this work, we have demonstrated for the first time how strains of Bifidobacterium and Lactobacillus are capable of carrying out the complete enterolignan metabolism, transforming a purified lignan (SECO) into enterodiol and enterolactone. The isolation and characterization of bacteria able to metabolize lignans and produce enterolignans, especially belonging to Bifidobacterium and Lactobacillus genera, is of biotechnological interest, because of their potential application in functional foods and as probiotics.Item Characterization of persistent Listeria monocytogenes strains from ten dry- cured ham processing facilities(Food Microbiology, 2020) D’Arrigo Matilde; Mateo-Vivaracho, Laura; Guillamón, Eva; Fernández León, María Fernanda; Bravo Vázquez, Daniel Antonio; Peirotén, Ángela; Medina, Margarita; García Lafuente, Ana; ElsevierThe majority of cases of listeriosis are associated with the consumption of contaminated food. Some strains of Listeria monocytogenes can persist over months or years in meat processing plants increasing the risk of product contamination. The presence of L. monocytogenes was examined in 10 dry-cured ham processing facilities. A total of 1801 samples were collected from environment and equipment, during processing (1095) and after cleaning and disinfection (706). These samples were taken from non-food contact (736) and food contact (1065) surfaces. In addition, 204 samples from ham surfaces were also analysed. Prevalence varied from 6% to 34% among facilities, and was higher during processing than after cleaning and disinfection (24.8% vs 11.0%) and from non-food than from food contact surfaces (22.6% vs 17.4%). L. monocytogenes serotype 1/2a was predominant (53.9%), followed by 1/2c (26.0%) and 1/2b (15.3%) and less frequently 4b (4.8%). A total of 142 different pulsotypes were registered. Potential persistent L.monocytogenes strains were isolated in 9 out the 10 facilities, with no more than 6 pulsotypes in a given plant. Two pulsotypes were common in different installations, detected before and after cleaning and disinfection, highlighting the importance of monitoring the presence of this pathogen in dry-cured ham processing environments.