Browsing by Subject "Antimicrobial activity"

Now showing 1 - 5 of 5
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    Antibacterial potential of commercial and wild lactic acid bacteria strains isolated from ovine and caprine raw milk against Mycoplasma agalactiae
    (Frontiers Media, 2023-06-22) Toquet, Marion; Bataller, Esther; Gomis Almendro, Jesús; Sánchez López, Antonio; Toledo-Perona, Raquel; de la Fe Rodríguez, Christian; Corrales Romero, Juan Carlos; Gómez-Martin, Ángel; Sanidad Animal
    Introduction: The complexity of fighting contagious agalactia (CA) has raised the necessity of alternative antimicrobial therapies, such as probiotics. Lactic acid bacteria (LAB) are present in the mammary gland of small ruminants and their antimicrobial effect have been previously described against species like Mycoplasma bovis but never against Mycoplasma agalactiae (Ma). This in vitro study aims to evaluate the antimicrobial activity against Ma of ovine and caprine LAB strains and a human commercial probiotic (L2) of Lactobacillus spp. Methods: A total of 63 possible LAB strains were isolated from nine ovine and caprine farms in Spain, three isolates (33B, 248D, and 120B) from the 63 strains were selected, based on their capacity to grow in a specific medium in vitro, for an in vitro experiment to assess their antimicrobial activity against Ma in Ultra High Temperature (UHT) processed goat milk (GM). A women commercial vaginal probiotic was also included in the study. The inoculum of L2 was prepared at a concentration of 3.24 × 108  CFU/mL and the average concentration of the inoculum of the wild LAB varied from 7.9 × 107 to 8.4 × 108  CFU/mL. Results: The commercial probiotic L2 significantly reduced the concentration of Ma to 0.000 log CFU/mL (p < 0.001), strain 33B reduced it from 7.185 to 1.279 log CFU/mL (p < 0.001), and 120B from 6.825 to 6.466 log CFU/mL (p < 0.05). Strain 248D presented a bacteriostatic effect in GM. Moreover, the three wild strains and the commercial probiotic produced a significative reduction of the pH (p < 0.001). Discussion: This is the first in vivo report of the antimicrobial potential of LAB strains against Ma and its interaction. Our results support possible future alternative strategies to antibiotic therapy, previously not contemplated, to fight CA in small ruminants. Further studies are necessary to elucidate the action mechanisms through which these LAB are able to inhibit Ma and to assess the safety of using these strains in possible in vivo studies.
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    Data set of Novel hepcidin genes in Gilthead Seabream: implications for immune response and iron metabolism
    (2025-04-24) García Navarro, Laura; Serna Duque, Jhon; Cuesta Peñafiel, Alberto; Esteban Abad, María de los Ángeles; Biología Celular e Histología
    Results of Synteny and phylogeny analysis of hamp2.0 and hamp2.15 in the class Actinopterygii, Bactericidal activity of HAMP2α or HAMP2Ω, Cytotoxicity activity of HAMP2α or HAMP2Ω. And a QuantStudio™ 5 Real-Time PCR System (Applied Biosystems).
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    Effect of pine bark extract and its phenolic compounds on selected pathogenic and probiotic bacterial strains
    (Frontiers, 2024-03-27) Sánchez Moya, Teresa; López Nicolás, Rubén; Peso Echarri, Patricia; González-Bermúdez, Carlos A.; Frontela-Saseta, Carmen; Tecnología de Alimentos, Nutrición y Bromatología
    Introduction: Inflammatory bowel disease (IBD) comprises a heterogeneous group of chronic diseases as ulcerative colitis (UC) and Crohn’s disease (CD). IBD is the result of a dysregulation of intestinal homeostasis with a host’s loss of tolerance toward normal enteric microflora. Plant-based extracts as phenolic compounds can play a role by modulating the intestinal inflammation response. Methods: The in vitro antimicrobial activity of French maritime pine bark extract (PBE) and its phenolic constituents has been investigated in this study. Furthermore, the ability of PBE and phenolic compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid and taxifolin) to modulate the microbiota has been assessed. Results: Phenolic compounds and PBE showed a great inhibitory effect on the pathogens growth at the highest concentration assessed (1.25 mg/mL). The growth of E. sakazakii and E. faecalis were affected by the effect of caffeic acid and ferulic acid. Taxifolin showed a very strong activity against Listeria sp. (with a reduction ~98%). Gallic acid revealed antibacterial effect on S. aureus at different concentrations. The inhibitory effect of PBE was highly significant on the growth of E. coli O157:H7. PBE, caffeic acid and chlorogenic acid seem to provide the greatest beneficial effect on the probiotic bacteria. However, the highest concentrations of taxifolin may have impaired the growth of beneficial microbiota. Conclusion: Present findings could be of interest for considering PBE and/or its phenolic constituents as protectors against gastrointestinal disturbances which lead to ulcerative colitis and Crohn’s disease.
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    Modification of chicha gum: antibacterial activity, ex vivo mucoadhesion, antioxidant activity and cellular viability
    (Elsevier, 2022-12-21) Freitas, Alessandra R.; Ribeiro, António J.; Ribeiro, Alessandra B.; Collado-González, Mar; Silva, Luís R.; Alves, Luís; Melro, Elodie; Antunes, Filipe E.; Veiga, Francisco; Morais, Alan I. S.; Bezerra, Roosvelt D. S.; Soares-Sobrinho, José L.; Osajima, Josy A.; Silva-Filho, Edson C.; Biología Celular e Histología
    The aim of the present work was to modify the exuded gum of Sterculia striata tree by an amination reaction. The viscosity and zero potential of the chicha gum varied as a function of pH. The modification was confirmed by Xray diffraction (XRD), infrared spectroscopy (FTIR), size exclusion chromatography (SEC), zeta potential, thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Furthermore, the chemical modification changed the molar mass and surface charge of the chicha gum. In addition, the gums were used in tests for ex vivo mucoadhesion strength, antibacterial activity against the standard strain of Staphylococcus aureus (ATCC 25923), inhibitory activity of α-glucosidase, antioxidant capacity, and viability of Caco-2 cells. Through these tests, it was found that amination caused an increase in the mucoadhesive and inhibitory activity of chicha gum against the bacterium Staphylococcus aureus. In addition, the gums (pure and modified) showed antioxidant capacity and an inhibitory effect against the α-glucosidase enzyme and did not show cytotoxic potential.
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    The Pseudoalteromonas luteoviolacea L-amino Acid Oxidase with Antimicrobial Activity Is a Flavoenzyme
    (MDPI, 2018) Andreo-Vidal, Andrés; Sanchez-Amat, Antonio; Campillo-Brocal, Jonatan C.; Genética y Microbiología
    The marine environment is a rich source of antimicrobial compounds with promising pharmaceutical and biotechnological applications. The Pseudoalteromonas genus harbors one of the highest proportions of bacterial species producing antimicrobial molecules. For decades, the presence of proteins with L-amino acid oxidase (LAAO) and antimicrobial activity in Pseudoalteromonas luteoviolacea has been known. Here, we present for the first time the identification, cloning, characterization and phylogenetic analysis of Pl-LAAO, the enzyme responsible for both LAAO and antimicrobial activity in P. luteoviolacea strain CPMOR-2. Pl-LAAO is a flavoprotein of a broad substrate range, in which the hydrogen peroxide generated in the LAAO reaction is responsible for the antimicrobial activity. So far, no protein with a sequence similarity to Pl-LAAO has been cloned or characterized, with this being the first report on a flavin adenine dinucleotide (FAD)-containing LAAO with antimicrobial activity from a marine microorganism. Our results revealed that 20.4% of the sequenced Pseudoalteromonas strains (specifically, 66.6% of P. luteoviolacea strains) contain Pl-laao similar genes, which constitutes a well-defined phylogenetic group. In summary, this work provides insights into the biological significance of antimicrobial LAAOs in the Pseudoalteromonas genus and shows an effective approach for the detection of novel LAAOs, whose study may be useful for biotechnological applications.