Enhancement of the antibacterial activity of an E. faecalis strain by the heterologous expression of enterocin A

Publication date: Available online 10 July 2018Source: Journal of BiotechnologyAuthor(s): Carlos Eduardo Serrano-Maldonado, Maricarmen QuirascoAbstractThe genus Enterococcus occurs as native microbiota of fermented products due to its broad environmental distribution and its resistance to salt concentrations. Enterococcus faecalis F, a non-pathogenic strain isolated from a ripened cheese, has demonstrated useful enzymatic capabilities, a probiotic behavior and antibacterial activity against some food-borne pathogens, mainly due to peptidoglycan hydrolase activity. Its use as a natural pathogen-control agent could be further enhanced through the production of a bacteriocin, e.g. Enterocin A, because of its remarkable antilisterial activity. In this work, a markerless allelic insertion method was used to obtain an enterococcal strain capable of producing a functional enterocin. Agar diffusion tests showed that the recombinant strain was active against Staphylococcus aureus, Listeria monocytogenes and the pathogenic strain E. faecalis V583. When grown in liquid culture together with L. monocytogenes, it attained a two-log reduction of the pathogen counts in lesser time relative to the native strain. Because the DNA construction is integrated into the chromosome, the improved strain avoids the use of antibiotics as selective pressure; besides, it does not require an inductor because of the inclusion of a constitutive promoter in the construction. Its technological and antibacteri...
Source: Journal of Biotechnology - Category: Biotechnology Source Type: research

Related Links:

The objective of this study was to investigate the effect of photodynamic inactivation, using two xanthene dyes (rose bengal and erythrosine) as photosensitizing agents and green LED as a light source, against Staphylococcus aureus, Listeria innocua, Enterococcus hirae and Escherichia coli in both planktonic and biofilm states. Both photosensitizing agents were able to control planktonic cells of all bacteria tested. The treatments altered the physicochemical properties of cells surface and also induced potassium leakage, indicating damage of cell membranes. Although higher concentrations of the photosensitizing agents (ra...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research
C, Capita R, Alonso-Calleja C Abstract The biofilms formed by Salmonella Hadar (SH174), Listeria monocytogenes (LM6), methicillin-resistant Staphylococcus aureus (MRSA125) and vancomycin-resistant Enterococcus faecium (VRE61s) on polystyrene and glass after 24 h and 72 h of incubation at 37 °C were examined by confocal laser scanning microscopy (CLSM) after staining with SYTO9 and propidium iodide (PI). A lower average biovolume (P 
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
Authors: Cao J, Gao S, Chen J, Zhu B, Min R, Wang P Abstract The present study prepared 2 types of DNA diagnostic chips based on 16S ribosomal DNA (rDNA) and 18S-28S rDNA, and evaluated their values in the detection of pathogens in intracranial bacterial/fungal infections. A total of 14 probes of bacteria (Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Haemophilus influenza, Stenotrophomonas maltophilia, Neisseria meningitidis, Enterobacter spp., Enterococcus faecalis, Enterococcus faecium, Listeria monocytogenes, Staphylococcus aureus, Streptococcus pneumonia and coagulase...
Source: Experimental and Therapeutic Medicine - Category: General Medicine Tags: Exp Ther Med Source Type: research
Publication date: August 2018Source: Journal of Environmental Chemical Engineering, Volume 6, Issue 4Author(s): Mohamed Azab El-Liethy, Khalid Z. Elwakeel, Mohammed S. AhmedAbstractMagnetic disinfectants were achieved through the polymerization of thiourea and formaldahyde in the presence of magnetite nano particles (MTUF), the as-prepared MTUF was loaded with Ag(I) or Au(III). The obtained disinfectants (MTUF-Ag and MTUF-Au) were test for some selected pathogenic strains deactivation. The toxicity of MTUF before and after Ag(I) or Au(II) loading was estimated. The antimicrobial activity tests of MTUF-Ag and MTUF-Au were c...
Source: Journal of Environmental Chemical Engineering - Category: Chemistry Source Type: research
Abstract One-pot synthesis of a new magnetic disinfectant was achieved through the polymerization of thiourea and formaldehyde in the presence of magnetite nanoparticles (MTUF). The obtained magnetic chelating resin was loaded with Ag(I) ions. This material was tested as a disinfectant for water pathogenic microorganism's deactivation. The toxicity of MTUF before and after Ag(I) loading was estimated. The antimicrobial activity tests of MTUF-Ag were carried out against Escherichia coli, Salmonella Typhimurium, and Pseudomonas aeruginosa as examples of Gram-negative bacteria; Listeria monocytogenes, Staphylococcus ...
Source: Environmental Science and Pollution Research International - Category: Environmental Health Authors: Tags: Environ Sci Pollut Res Int Source Type: research
Abstract The bacteriocin enterocin-B contains broad anti-microbial spectrum against several gram positive, negative pathogenic bacteria was cloned, overexpressed and purified from Enterococcus faecium por1. The molecular weight of the bacteriocin enterocin-B was observed around 7.2 kDa and interacting, formation of heterodimer with another bacteriocin enterocin-A from the same organism by protein-protein docking and molecular dynamics simulation studies. The heterodimer of bacteriocin enterocin-A + B exhibited potential anti-bacterial, anti-biofilm activity against Staphylococcus aureus, Listeria monocytogen...
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Tags: Int J Biol Macromol Source Type: research
This study evaluated the effect of a novel formulation for starter culture associated with specific ripening conditions (NoNit™ technology) vs. a commercial» starter on the fate of selected pathogens and hygiene indicators during the fermentation and ripening of experimentally spiked salame nostrano (Italian dry sausage). Selected strains of Staphylococcus aureus 27R, Escherichia coli CSH26 K 12, Listeria innocua ATCC 33090 and Salmonella Derby 27 were inoculated into salami batter and challenged with two formulations of starter cultures (a commercial formulation and the NoNit™ formulation, consisting of ...
Source: Meat Science - Category: Food Science Source Type: research
Publication date: Available online 3 January 2018 Source:Microbial Pathogenesis Author(s): Shuai Wei, Ramachandran Chelliah, Byung-Jae Park, Joong-Hyun Park, Fereidoun Forghani, Youn-Seo Park, Min-Seok Cho, Dong-Suk Park, Deog-Hwan Oh The aim of the study was to identify and evaluate specific biomarkers to differentiate within Bacillus cereus group species from contaminated food samples with the use of real-time PCR. A total of 120 strains, comprising of 28 reference, 2 type, 78 wild strains of B. cereus and B. thuringiensis along with 12 strains representing 2 bacterial groups – B. mycoides, B. pseudomycoides, B. w...
Source: Microbial Pathogenesis - Category: Infectious Diseases Source Type: research
Conclusion: The presence of virulence genes in E. faecalis TA102 calls for careful monitoring of Enterococcus isolates for their safety parameters. PMID: 29238458 [PubMed]
Source: Iranian Journal of Microbiology - Category: Microbiology Tags: Iran J Microbiol Source Type: research
Abstract Host cell adhesion assays that provide quantitative insight on the potential of lactic acid bacteria (LAB) to inhibit adhesion of intestinal pathogens can be leveraged for the development of niche-specific anti-adhesion therapy. Herein, we report a dual-colour flow cytometry (FCM) analysis to assess the ability of probiotic Lactobacillus plantarum strains to impede adhesion of Enterococcus faecalis, Listeria monocytogenes and Staphylococcus aureus onto HT-29 cells. FCM in conjunction with a hierarchical cluster analysis could discern the anti-adhesion potential of L. plantarum strains, wherein the efficac...
Source: Microbiology - Category: Microbiology Authors: Tags: Microbiology Source Type: research
More News: Biotechnology | Enterococcus | Environmental Health | Listeria | Probiotics | Sodium Chloride | Staphylococcus Aureus