Benefits and Inputs From Lactic Acid Bacteria and Their Bacteriocins as Alternatives to Antibiotic Growth Promoters During Food-Animal Production

Resistance to antibiotics is escalating and threatening humans and animals worldwide. Different countries have legislated or promoted the ban of antibiotics as growth promoters in livestock and aquaculture to reduce this phenomenon. Therefore, to improve animal growth and reproduction performance and to control multiple bacterial infections, there is a potential to use probiotics as non-antibiotic growth promoters. Lactic acid bacteria (LAB) offer various advantages as potential probiotics and can be considered as alternatives to antibiotics during food-animal production. LAB are safe microorganisms with abilities to produce different inhibitory compounds such as bacteriocins, organic acids as lactic acid, hydrogen peroxide, diacetyl, and carbon dioxide. LAB can inhibit harmful microorganisms with their arsenal, or through competitive exclusion mechanism based on competition for binding sites and nutrients. LAB endowed with specific enzymatic functions (amylase, protease…) can improve nutrients acquisition as well as animal immune system stimulation. This review aimed at underlining the benefits and inputs from LAB as potential alternatives to antibiotics in poultry, pigs, ruminants, and aquaculture production

Purification et caractérisations du mode d'action et de l'innocuité de l'entérocine S37, une bactériocine produite par Enterococcus faecalis S37

La sécurité et l hygiène des aliments est une préoccupation majeure des sociétés modernes. Le développement de bactéries pathogènes des aliments à l instar de Camplyobacter jejuni et Listeria monocytogenes exige la recherche de nouvelles méthodes de lutte contre ces microorganismes. Les bactériocines produites par les bactéries lactiques constituent une alternative intéressante qu il convient de continuer d explorer et valoriser. Dans cette thèse, nous nous sommes intéressés à l écosystème digestif du poulet en vue d isoler de nouvelles bactéries lactiques bactériocinogènes. Il résulte de notre étude une prédominance du genre Lactobacillus. Parmi les bactéries lactiques bactériocinogènes identifiées, il y a Enterococcus faecalis S37 qui présente une activité anti-Listeria forte et anti-Campylobacter variable. Cette activité est attribuée à la production d une bactériocine nommée entérocine S37. Nous avons purifié l entérocine S37 par des méthodes chromatographiques et caractérisé son mode d action. L entérocine S37 a un poids moléculaire compris entre 4 et 6 kDa, elle résiste aux traitements thermiques et pH extrêmes. Elle est active principalement contre les souches de Listeria monocytogenes et Enterococcus faecalis. Le mode d action de l entérocine S37, étudié grâce à l utilisation de modulateurs de canaux potassiques a montré une interaction avec les canaux potassiques ATP dépendants provoquant la fuite d ions K+ et des molécules d ATP intracellulaires. Par ailleurs, l innocuité de l entérocine S37 a été démontrée sur un modèle cellulaire entérocitaire Caco- 2/TC7 différenciées, faisant de cette bactériocine un candidat potentiel pour une utilisation en prévention de ces microorganismes. Nous avons également montré que la combinaison de la nisine A et/ou pédiocine PA-1 avec la polymyxine E permet un effet additif et/ou synergique sur des souches résistantes de Listeria monocytogenes.Development of foodborne pathogens such as Campylobacter jejuni and Listeria monocytogenes encourages the search of novel technologies in order to fight against the aforementioned bacteria. Bacteriocins produced by lactic acid bacteria stand as an interesting issue. In this project we studied and established the lactic acid bacteria present in chicken digestive tract. Consequently, the genus Lactobacillus was the predominant one, and Enterococcus faecalis S37 exhibited antagonism against Listeria monocytogenes while an unstable anti-Campylobacter activity was observed. This strain produces a bacteriocin, named enterocin S37, which was purified by a set of chromatographical methods. Enterocin S37 has a molecular weight comprised between 4 and 6 kDa, and a good resistance to elevated temperatures and pH extremes. Enterocin S37 was active against listerial and enterococcal strains. The mode of action of enterocin S37 was studied by using different potassium channels modulators. Such investigations concluded to ATP-dependent potassium channels interaction of enterocin S37, leading to leakage of K+ and intracellular ATP. Furthermore we established that enterocin S37 did not affect differentiated Caco-2/TC7 cells arguing on the capacities of enterocin S37 to be used in prevention of the aforementioned bacteria and certain infection. Additionally, we demonstrated the synergistic effect of nisin A and pediocin PA-1, when combined with polymyxin E (antibiotic) against resistant and sensitive listerial strains.NANTES-BU Sciences (441092104) / SudocSudocFranceF

Broadening and enhancing bacteriocins activities by association with bioactive substances

International audienceBacteriocins are antimicrobial peptides some of which are endowed with antiviral, anticancer and antibiofilm properties. These properties could be improved through synergistic interactions of these bacteriocins with other bioactive molecules such as antibiotics, phages, nanoparticles and essential oils. A number of studies are steadily reporting the effects of these combinations as new and potential therapeutic strategies in the future, as they may offer many incentives over existing therapies. In particular, bacteriocins can benefit from combination with nanoparticles which can improve their stability and solubility, and protect them from enzymatic degradation, reduce their interactions with other molecules and improve their bioavailability. Furthermore, the combination of bacteriocins with other antimicrobials is foreseen as a way to reduce the development of antibiotic resistance due to the involvement of several modes of action. Another relevant advantage of these synergistic combinations is that it decreases the concentration of each antimicrobial component, thereby reducing their side effects such as their toxicity. In addition, combination can extend the utility of bacteriocins as antiviral or anticancer agents. Thus, in this review, we report and discuss the synergistic effects of bacteriocin combinations as medicines, and also for other diverse applications including, antiviral, antispoilage, anticancer and antibiofilms

Lacticaseicin as a novel emerging bacteriocin with clinical future

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Potentiating effects of leaderless enterocin DD14 in combination with methicillin on clinical methicillin-resistant Staphylococcus aureus S1 strain

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Clusters of Lactobacillus Strains from Vegetal Origins Are Associated with Beneficial Functions: Experimental Data and Statistical Interpretations

Nine strains of Lactiplantibacillus plantarum and one strain of Lacticaseibacillus paracasei that were recently isolated from prickly pears, fresh figs and blackberries, which are traditionally and largely consumed fruits in Kabylia (north of Algeria), were studied here for their antagonism and antioxidant properties as well as for production of exopolysaccharides. With respect to their inhibitory properties, these strains were tested against three food representative pathogens including Escherichia coli ATCC 8739, Staphylococcus aureus 2S6 and Listeria monocytogenes 162. The antagonism of these pathogens was attributable to lactic acid production, present in the cell free supernatant, at concentrations ranging from 9 to 16.74 g/L. The anti-adhesive properties observed on polystyrene or eukaryotic Caco-2 cells were exerted in a strain dependent-manner. Indeed, the scores obtained ranged from 27% to 75% for S. aureus 2S6, 54% to 95% for L. monocytogenes 162, and 50% to 97% for E. coli ATCC 8739. The co-aggregation of these Lactobacillus strains with the aforementioned target bacteria appeared to be exerted in a strain-dependent manner, with noticeably the upmost rate for Lb. paracasei FB1 on S. aureus 2S6. Interestingly, these novel Lactobacillus strains were able to produce a large amount (315.55 to 483.22 mg/L) of exopolysaccharides, and showed a significant scavenging activity on the 2,2-di-phényl-2-picrylhydrazyle (DPPH) synthetic free radical with rates of 51% to 56%. Of note, the highest antioxidant activity was observed for Lb. paracasei FB1 using the culture supernatants, intact cells or the intracellular extract. The statistical analysis of these data using the principal component analysis (ACP) enabled us to establish three distinct clusters with potential applications as bioprotective and/or probiotic agents, following further evaluation

Draft Genome Sequence of Enterococcus faecalis DD14, a Bacteriocinogenic Lactic Acid Bacterium with Anti- Clostridium Activity

International audienceABSTRACT We report the draft genome sequence of Enterococcus faecalis DD14, a strain isolated from meconium of a healthy newborn at Roubaix Hospital (France). The strain displayed antagonism against a set of Gram-positive bacteria through concomitant production of lactic acid and bacteriocin. The genome has a size of 2,893,365 bp and a 37.3% G+C ratio and is predicted to contain at least 2,755 coding sequences and 62 RNAs

Safety and antagonism relevance of Trichosporon asahii ICVY021 isolated from she-camel milk.

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Lactecaseicin 30: One of the bacteriocins from Lacticaseibacillus paracasei CNCM I-5369 and its engineered variants revealed activity against Gram-negative bacteria

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Impact of seasonality and environmental conditions on yeast diversity from camel’s milk collected in Algeria

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