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Francisco R Fields, Katelyn E Carothers, Rashna D Balsara, Victoria A Ploplis, Francis J Castellino, Shaun W Lee
Bacteriocins hold unprecedented promise as a largely untapped source of antibiotic alternatives in the age of multidrug resistance. Here, we describe the first approach to systematically design variants of a novel AS-48 bacteriocin homologue, which we have termed safencin AS-48, from Bacillus safensis, to gain insights into engineering improved activity of bacteriocins. A library of synthetic peptides in which systematic amino acid substitutions to vary the periodicity and abundance of polar, acidic, aliphatic, and hydrophobic residues were generated for a total of 96 novel peptide variants of a single bacteriocin candidate...
February 20, 2018: Journal of Antibiotics
Stephen A Jackson, Lisa Crossman, Eduardo L Almeida, Lekha Menon Margassery, Jonathan Kennedy, Alan D W Dobson
The genus Streptomyces produces secondary metabolic compounds that are rich in biological activity. Many of these compounds are genetically encoded by large secondary metabolism biosynthetic gene clusters (smBGCs) such as polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) which are modular and can be highly repetitive. Due to the repeats, these gene clusters can be difficult to resolve using short read next generation datasets and are often quite poorly predicted using standard approaches...
February 20, 2018: Marine Drugs
Benoit Chassaing, Eric Cascales
The intestinal microbiota plays an important role in health, particularly in promoting intestinal metabolic capacity and in maturing the immune system. The intestinal microbiota also mediates colonization resistance against pathogenic bacteria, hence protecting the host from infections. In addition, some bacterial pathogens deliver toxins that target phylogenetically related or distinct bacterial species in order to outcompete and establish within the microbiota. The most widely distributed weapons include bacteriocins, as well as contact-dependent growth inhibition and type VI secretion systems...
February 13, 2018: Trends in Microbiology
Hirotoshi Sushida, Naoki Ishibashi, Takeshi Zendo, Pongtep Wilaipun, Vichien Leelawatcharamas, Jiro Nakayama, Kenji Sonomoto
EnkT is a novel ATP-binding cassette (ABC) transporter responsible for secretion of four bacteriocins, enterocins NKR-5-3A, C, D, and Z (Ent53A, C, D, and Z), produced by Enterococcus faecium NKR-5-3. It is generally recognized that the secretion of a bacteriocin requires a dedicated ABC transporter, although molecular mechanisms of this secretion are yet to be revealed. In order to characterize the unique ability of EnkT to secrete multiple bacteriocins, the role of N-terminal leader peptides of bacteriocin precursors was evaluated using Ent53C precursor as a model...
February 13, 2018: Journal of Bioscience and Bioengineering
Johann Mignolet, Laetitia Fontaine, Andrea Sass, Catherine Nannan, Jacques Mahillon, Tom Coenye, Pascal Hols
Small distortions in transcriptional networks might lead to drastic phenotypical changes, especially in cellular developmental programs such as competence for natural transformation. Here, we report a pervasive circuitry rewiring for competence and predation interplay in commensal streptococci. Canonically, in streptococci paradigms such as Streptococcus pneumoniae and Streptococcus mutans, the pheromone-based two-component system BlpRH is a central node that orchestrates the production of antimicrobial compounds (bacteriocins) and incorporates signal from the competence activation cascade...
February 13, 2018: Cell Reports
Maarten G K Ghequire, Susan K Buchanan, René De Mot
Bacteria host an arsenal of antagonism-mediating molecules to combat for ecologic space. Bacteriocins represent a pivotal group of secreted antibacterial peptides and proteins assisting in this fight, mainly eliminating relatives. Colicin M, a model for peptidoglycan-interfering bacteriocins in Gram-negative bacteria, appears to be part of a set of polymorphic toxins equipped with such a catalytic domain (ColM) targeting lipid II. Diversifying recombination has enabled parasitism of different receptors and has also given rise to hybrid bacteriocins in which ColM is associated with another toxin module...
February 13, 2018: MBio
Jong-Hoon Lee, Sojeong Heo, Do-Won Jeong
BACKGROUND: Our previous comparative genomic analysis of Staphylococcus equorum KS1039 with five S. equorum strains illuminated the genomic basis of its safety and salt tolerance. However, a comprehensive picture of the cellular components and metabolic pathways involved in the degradation of macromolecules and development of sensory properties has not been obtained for S. equorum. Therefore, in this study, we examined the general metabolism of S. equorum based on information obtained from published complete genome sequences of six S...
February 13, 2018: BMC Genomics
Rodrigo Otávio Miranda, Maria Emilene Martino Campos-Galvão, Luís Augusto Nero
The use of nisin producers in foods is considered a mitigation strategy to control foodborne pathogens growth, such as Listeria monocytogenes, due to the production of this bacteriocin in situ. However, when the bacteriocin does not reach an adequate concentration, the target bacteria can develop a cross-response to different stress conditions in food, such as acid, thermal and osmotic. This study aimed to evaluate the interaction of a nisin-producing strain of Lactococcus lactis DY-13 and L. monocytogenes in BHI and skim milk, and its influence on general (sigB), acid (gadD2), thermal (groEL) and osmotic (gbu) stress-related genes of the pathogen...
March 2018: Food Research International
Géssica A Costa, Fernanda C P Rossatto, Aline W Medeiros, Ana Paula F Correa, Adriano Brandelli, Ana Paula G Frazzon, Amanda DE S DA Motta
The adhesion ability of bacteria to abiotic surfaces has important implications in food industries, because these organisms can survive for long periods through the biofilm formation. They can be transferred from one place to another in the industry causing contamination of the food processing environment. In this study, the antibacterial and antibiofilm activities of the antimicrobial peptide P34, characterized as a bacteriocin-like substance (BLS P34) were tested against planktonic and sessile cells of Staphylococcus aureus and Enterococcus faecalis isolated from foods...
February 1, 2018: Anais da Academia Brasileira de Ciências
A S Vasilchenko, A V Vasilchenko, A V Valyshev, E A Rogozhin
Discovery of a novel bacteriocin is always an event in sciences, since cultivation of most bacterial species is a general problem in microbiology. This statement is reflected by the fact that number of bacteriocins is smaller for tenfold comparing to known antimicrobial peptides. We cultivated Enterococcus faecium on simplified medium to reduce amount of purification steps. This approach allows to purify the novel heavy weight bacteriocin produced by E. faecium ICIS 7. The novelty of this bacteriocin, named enterocin-7, was confirmed by N-terminal sequencing and by comparing the structural-functional properties with available data...
February 8, 2018: Probiotics and Antimicrobial Proteins
Andrea Lauková, Eva Styková, Ivana Kubašová, Soňa Gancarčíková, Iveta Plachá, Dagmar Mudroňová, Anna Kandričáková, Renata Miltko, Grzegorz Belzecki, Igor Valocký, Viola Strompfová
Probiotic bacteria or their antimicrobial proteinaceous substances called bacteriocins (enterocins) hold promising prophylactic potential for animal breeding. This study present the results achieved after application of Enterocin M in horses. Enterocin M has never been applied to horses before. Clinically healthy horses (10) were involved in this pilot experiment. They were placed in the stables of the University of Veterinary Medicine and Pharmacy, Košice, Slovakia, with the approval of the University Ethics Committee...
February 7, 2018: Probiotics and Antimicrobial Proteins
Van Son Nguyen, Badreddine Douzi, Eric Durand, Alain Roussel, Eric Cascales, Christian Cambillau
The Type VI secretion system (T6SS) is a dynamic nanomachine present in many Gram-negative bacteria. Using a contraction mechanism similar to that of myophages, bacteriocins or anti-feeding prophages, it injects toxic effectors into both eukaryotic and prokaryotic cells. T6SS assembles three large ensembles: the trans-membrane complex (TMC), the baseplate and the tail. Recently, the tail structure has been elucidated by cryo electron microscopy (cryoEM) in extended and contracted forms. The structure of the trans-membrane complex has been deciphered using a combination of X-ray crystallography and EM...
February 1, 2018: Current Opinion in Structural Biology
Sai Nithya, T R Nimal, Gaurav Baranwal, Maneesha K Suresh, Anuj C P, V Anil Kumar, C Gopi Mohan, R Jayakumar, Raja Biswas
Lysostaphin (LST) is a bacteriocin that cleaves within the pentaglycine cross bridge of Staphylococcus aureus peptidoglycan. Previous studies have reported the high efficiency of LST even against multi drug resistant S. aureus including methicillin resistant S. aureus (MRSA). In this study, we have developed a new chitosan based hydrogel formulation of LST to exploit its anti-staphylococcal activity. The atomic interactions of LST with chitosan were studied by molecular docking studies. The rheology and the antibacterial properties of the developed LSTC gel were evaluated...
February 2, 2018: International Journal of Biological Macromolecules
Marina Giello, Antonietta La Storia, Francesca De Filippis, Danilo Ercolini, Francesco Villani
Lactobacillus curvatus 54M16 produced bacteriocins sak X, sak Tα, sak Tβ and sak P. The aim of this study was to investigate the anti-listerial activity of the bacteriocins-producing strain against Listeria monocytogenes in vitro co-culture experiments and during the manufacture of fermented sausages. In MRS broth, Lb. curvatus 54M16 was able to inhibit L. monocytogenes to undetectable levels after 48 h at 20 °C or 5 days at 15 °C. Anti-listerial activity was lower during the production of fermented sausages with pathogen inoculation at levels of approximately 4 Log CFU g-1...
June 2018: Food Microbiology
Garima Sharma, Shweta Dang, Sanjay Gupta, Reema Gabrani
OBJECTIVE: The aim of this study was to purify and characterize the bacteriocin from soil isolate Bacillus subtilis GAS101 and to determine its antimicrobial as well as antibiofilm potential. Purified bacteriocin was further analyzed and evaluated for mammalian cell cytotoxicity and possible mode of action. MATERIAL AND METHODS: Bacteriocin from B. subtilis GAS101 (animal husbandry soil isolate) was partially purified and checked for antimicrobial and antibiofilm activity against Gram-positive and Gram-negative bacteria...
January 31, 2018: Medical Principles and Practice: International Journal of the Kuwait University, Health Science Centre
Izildinha Moreno, Elza Teresinha Grael Marasca, Patrícia Blumer Zacarchenco Rodrigues de Sá, Josiane de Souza Moitinho, Miriam Gonçalves Marquezini, Márcia Regina Cucatti Alves, Renata Bromberg
In this study, the probiotic potential of five bacteriocin-producing lactic acid bacteria (LAB) strains, isolated from meat products, was investigated. They were presumptively identified as Lactococcus lactis subsp. cremoris CTC 204 and CTC 483, L. lactis subsp. hordinae CTC 484, and Lactobacillus plantarum CTC 368 and CTC 469 according to morphological, biochemical, and physiological characteristics. Analysis of genetic variability (random amplified polymorphic (RAPD)-PCR) and whole-cell proteins (SDS-PAGE) revealed similarity between Lactobacillus strains and variability among Lactococcus strains...
February 2, 2018: Probiotics and Antimicrobial Proteins
Patricia Castellano, Natalia Peña, Mariana Pérez Ibarreche, Fernando Carduza, Trinidad Soteras, Graciela Vignolo
Dipping solutions containing bacteriocins produced by Lactobacillus curvatus CRL705 and Lactobacillus sakei CRL1862 (Bact705/1862), nisin and organic acids (lactic acid, LA; acetic acid, AA) were tested alone or in combination against Listeria monocytogenes inoculated by immersion on vacuum-packaged frankfurters stored at 10 °C during 36 days. LA/AA solution (2.5% v/v each) reduced pathogen population by 1.50 log10 CFU/ml during storage. Semi-purified Bact705/1862 prevented L. monocytogenes growth, while nisin was not able to avoid its regrowth after 20 days...
February 2018: Journal of Food Science and Technology
Márcia Oliveira, Vânia Ferreira, Rui Magalhães, Paula Teixeira
Naturally fermented meat sausages have a long tradition in Mediterranean countries and are one of the most important groups of traditional foods consumed throughout Europe. Despite all the advances in food science and technology and increased regulatory requirements and concerns for safety and quality during the last decades, the challenge to control important foodborne pathogens in this type of meat products still persists. Simultaneously, growing consumer interest in safe, high quality and minimal processed products, with less additives/preservatives have driven the food industry and scientists in a crusade for innovative technologies to maintain the safety of these products by natural means...
January 2018: Food Research International
Myrna Olvera-García, Alejandro Sanchez-Flores, Maricarmen Quirasco Baruch
Enterococcus spp. are present in the native microbiota of many traditional fermented foods. Their ability to produce antibacterial compounds, mainly against Listeria monocytogenes, has raised interest recently. However, there is scarce information about their proteolytic and lipolytic potential, and their biotechnological application is currently limited because enterococcal strains have been related to nosocomial infections. In this work, next-generation sequencing and optimised bioinformatic pipelines were used to annotate the genomes of two Enterococcus strains-one E...
January 25, 2018: Applied Microbiology and Biotechnology
En Yang, Lihua Fan, Jinping Yan, Yueming Jiang, Craig Doucette, Sherry Fillmore, Bradley Walker
There has been continued interest in bacteriocins research from an applied perspective as bacteriocins have potential to be used as natural preservative. Four bacteriocinogenic lactic acid bacteria (LAB) strains of Lactobacillus curvatus (Arla-10), Enterococcus faecium (JFR-1), Lactobacillus paracasei subsp. paracasei (JFR-5) and Streptococcus thermophilus (TSB-8) were previously isolated and identified in our lab. The objective of this study was to determine the optimal growth conditions for both LAB growth and bacteriocins production...
January 24, 2018: AMB Express
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