Study of the Antibacterial Activity of Rich Polyphenolic Extracts Obtained from Cytisus scoparius against Foodborne Pathogens.

Natural extracts containing high polyphenolic concentrations may act as good antimicrobials for their antibacterial and antibiofilm activity. The present research characterizes two hydro-organic extracts with high polyphenolic content, obtained from the shrub Cytisus scoparius as antipathogenic candidates. As a result of their own composition, both extracts, LE050 and PG050, have shown pronounced bioactivities with potential uses, especially in agricultural, livestock production, food manufacturing, and pharmaceutical industries. Polyphenolic compounds were extracted by using adjusted hydro-organic solvent mixtures. These extracts' in vitro antimicrobial activity was evaluated on Gram-positive and Gram-negative pathogenic bacteria, giving special attention to those involved in food contamination. Due to this, the biofilm dispersion was assessed on Listeria monocytogenes, Staphylococcus aureus and Pseudomonas aeruginosa. The extracts showed antimicrobial activity against the pathogenic species tested, presenting IC50 values between 0.625-20% v/v. Different behaviors have been detected between both extracts, probably linked to their distinct polyphenol composition, being LE050 extract the one with most promising bioactive applications. Finally, the results from the biofilm dispersion assays reveal that the extracts exhibit a good antibiofilm activity against the pathogenic bacteria tested.

Antibacterial Activity against Clinical Strains of a Natural Polyphenolic Extract from Albariño White Grape Marc.

Infections caused by multidrug-resistant bacteria are becoming increasingly frequent and sometimes difficult to treat due to the limited number of antibiotics active against them. In addition, they can spread between countries and/or continents, which is a problem of great relevance worldwide. It is, therefore, urgent to find alternatives to treat infections caused by multidrug-resistant bacteria. This study aimed at exploring a possible therapeutic alternative in the fight against antibiotic resistance. Based on the known antibacterial capacity of polyphenols, we tested the antimicrobial activity of a polyphenolic extract of Albariño white grape marc on clinical strains since research on such bacteria has been very scarce until now. First, the extract was obtained using a medium-scale ambient temperature (MSAT) system, which is an efficient and sustainable extractive method. The determinations of the polyphenolic content of the extract and its antioxidant capacity showed good results. Using chromatographic and mass spectrometric tools, 13 remarkable polyphenols were detected in the extract. The antibacterial activity of our grape marc extract against nineteen clinical strain isolates, some of which are multidrug-resistant, was evaluated by means of the calculation of half of the maximum inhibitory concentration (IC50) and the value of the minimum bactericidal concentrations (MBCs). In conclusion, the extract showed effectiveness against all clinical strains tested, regardless of their level of antibiotic resistance, and shows promise in the fight against antibiotic resistance.

Antimicrobial Activity of Polyphenols and Natural Polyphenolic Extracts on Clinical Isolates.

Antibiotic resistance is a growing global problem that affects people, animals, the environment, and the economy. Many clinically relevant bacteria have become resistant to antibiotics, and this fact is emerging as one of the major threats to public health. The lack of new antibiotics, which is due to their time-consuming and costly development, exacerbates the problem. Therefore, it is necessary to identify new antimicrobial agents to treat bacterial and fungal infections. Plant extracts, which are valuable sources of bioactive compounds, mainly polyphenols, play an important role as a new strategy to combat pathogenic microorganisms. There is an extensive body of supporting evidence for the potent antibacterial and antifungal activities of polyphenols. Furthermore, some polyphenols show a synergistic effect when combined with antibiotics and antifungals, suggesting a promising alternative for therapeutic strategies against antibiotic resistance. However, only a few articles are found when searching the antibacterial or antifungal activities of polyphenols employing clinical isolates. Hence, this review focuses on the antimicrobial activity of polyphenols and extracts rich in polyphenols on clinical isolates, organized according to the World Health Organization priority pathogens classification.

Polyphenolic content and bioactivities of Crataegus oxyacantha L. (Rosaceae).

Solid-Liquid Extraction (SLE) using solvent of different polarities (CHCl3, EtOAc, and n-BuOH) has been applied to leaves and fruits from (Crataegus oxyacantha L.), a deciduous shrub with an expected rich phytochemical profile. The total polyphenols content and the radical scavenging activity of each extract were evaluated. These extracts were analyzed by HPLC-DAD and rutin, quercetin-3-glucoside, caftaric and caffeic acid had been positively identified. The phytochemical study of the ethyl acetate extract of C. oxyacantha, led to the isolation and structural elucidation of quercetin (1); quercetin-3-O-ß-glucoside (2); epicatechin (3); naringenin (4), reported for the first time from this species except caffeic acid and epicatechin. These compounds were identified by 1D and 2D NMR combined analysis as well as by MS and UV.The antimicrobial activity of these extracts has also been tested, showing strong antibacterial activity-solvent dependent-against Gram positive bacteria. Additionally, bactericidal power was demonstrated in fruit extracts.

Exploring the powerful phytoarsenal of white grape marc against bacteria and parasites causing significant diseases.

Natural extracts containing high polyphenolic concentration possess antibacterial, anti-parasitic and fungicidal activities. The present research characterises two extracts based on white grape marc, a winemaking by-product, describing their physicochemical features and antimicrobial capacities. The main components of these extracts are phenolic acids, flavan-3-ols and their gallates and flavonols and their glycosides. As a result of this complex composition, the extracts showed pronounced bioactivities with potential uses in agricultural, pharmaceutical and cosmetic industries. Polyphenol compounds were extracted by using hydro-organic solvent mixtures from the by-product of Albariño white wines (Galicia, NW Spain) production. The in vitro antimicrobial activity of these extracts was evaluated on Gram-positive and Gram-negative bacteria and Apicomplexan and Oomycota parasites. Microbial species investigated are causing agents of several human and animal diseases, such as foodborne illnesses (Bacillus cereus, Escherichia coli, Salmonella enterica, and Toxoplasma gondii), skin infections and/or mastitis (Staphylococcus aureus and Streptococcus uberis), malaria (Plasmodium falciparum) and plant infections as "chestnut ink" or "root rot" (Phytophthora cinnamomi). Both extracts showed activity against all the tested species, being nontoxic for the host. So, they could be used for the development of biocides to control a wide range of pathogenic agents and contribute to the enhancement of winemaking industry by-products.

Bacteriophages and Lysins as Possible Alternatives to Treat Antibiotic-Resistant Urinary Tract Infections.

Urinary tract infections represent a major public health problem as the rapid emergence of antibiotic-resistant strains among uropathogens is causing the failure of many current treatments. The use of bacteriophages (phages) and their derivatives to combat infectious diseases is an old approach that has been forgotten by the West for a long time, mostly due to the discovery and great success of antibiotics. In the present so-called "post-antibiotic era", many researchers are turning their attention to the re-discovered phage therapy, as an effective alternative to antibiotics. Phage therapy includes the use of natural or engineered phages, as well as their purified lytic enzymes to destroy pathogenic strains. Many in vitro and in vivo studies have been conducted, and these have proved the great potential for this therapy against uropathogenic bacteria. Nevertheless, to date, the lack of appropriate clinical trials has hindered its widespread clinic application.

A Hundred Years of Bacteriophages: Can Phages Replace Antibiotics in Agriculture and Aquaculture?

Agriculture, together with aquaculture, supplies most of the foodstuffs required by the world human population to survive. Hence, bacterial diseases affecting either agricultural crops, fish, or shellfish not only cause large economic losses to producers but can even create food shortages, resulting in malnutrition, or even famine, in vulnerable populations. Years of antibiotic use in the prevention and the treatment of these infections have greatly contributed to the emergence and the proliferation of multidrug-resistant bacteria. This review addresses the urgent need for alternative strategies for the use of antibiotics, focusing on the use of bacteriophages (phages) as biocontrol agents. Phages are viruses that specifically infect bacteria; they are highly host-specific and represent an environmentally-friendly alternative to antibiotics to control and kill pathogenic bacteria. The information evaluated here highlights the effectiveness of phages in the control of numerous major pathogens that affect both agriculture and aquaculture, with special emphasis on scientific and technological aspects still requiring further development to establish phagotherapy as a real universal alternative to antibiotic treatment.

Fabrication of Zn-Sr-doped laser-spinning glass nanofibers with antibacterial properties.

The morphology and dimensions of bioactive materials are essential attributes to promote tissue culture. Bioactive materials with nanofibrous structure have excellent potential to be used as bone-defect fillers, since they mimic the collagen in the extracellular matrix. On the other hand, bioactive glasses with applications in regenerative medicine may present antibacterial properties, which depend on glass composition, concentration and the microorganisms tested. Likewise, their morphology may influence their antibacterial activity too. In the present work, the laser-spinning technique was used to produce bioactive glass nanofibers of two different compositions: 45S5 Bioglass® and ICIE16M, bioactive glass doped with zinc and strontium. Their antibacterial activity against Staphylococcus aureus was tested by culturing them in dynamic conditions. Bacterial growth index profiles during the first days of experiment can be explained by the variations in the pH values of the media. The bactericidal effect of the doped nanofibers at longer times is justified by the release of zinc and strontium ions. Cytotoxicity was analyzed by means of cell viability tests performed with BALB/3T3 cell line.

Paenibacillus favisporus sp. nov., a xylanolytic bacterium isolated from cow faeces.

During a search for xylan-degrading micro-organisms, a sporulated bacterium was recovered from recent and old cow dung and rectal samples. The isolates were identified as members of a novel species of the genus Paenibacillus, based on 16S rRNA gene sequences. According to the results of phylogenetic analysis, the most closely related species was Paenibacillus azoreducens. Phenotypic and chemotaxonomic analyses and DNA-DNA hybridization experiments also showed that the isolates belonged to a novel species of the genus Paenibacillus. The novel species is a facultatively anaerobic, motile, Gram-variable, sporulated rod. The spores of this rod-shaped micro-organism occur in slightly swollen sporangia and are honeycomb-shaped. The main fatty acid is anteiso-branched C(15:0). Growth was observed with many carbohydrates, including xylan, as the only carbon source and gas production was not observed from glucose. The novel species produces a wide variety of hydrolytic enzymes, such as xylanases, cellulases, amylases, gelatinase, urease and beta-galactosidase. On the contrary, it does not produce caseinase, phenylalanine deaminase or lysine decarboxylase. According to the data obtained in this work, the strains belong to a novel species, for which the name Paenibacillus favisporus sp. nov. is proposed (type strain, GMP01T=LMG 20987T=CECT 5760T).