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1.
J Appl Microbiol ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38925659

RESUMO

AIMS: This study aimed to prospect and isolate LAB from an artisanal cheese production environment, to assess their safety, and to explore their bacteriocinogenic potential against Listeria monocytogenes. METHODS AND RESULTS: Samples were collected from surfaces of an artisanal-cheese production facility and after rep-PCR and 16S rRNA sequencing analysis, selected strains were identified to be belonging to Lactococcus garvieae (1 strain) and Enterococcus faecium (14 isolates, grouped into 3 clusters) associated with different environments (worktables, cheese mold, ripening wooden shelves). All of them presented bacteriocinogenic potential against L. monocytogenes ATCC 7644 and were confirmed as safe (γ-hemolytic, not presenting antibiotic resistance, no mucus degradation properties and no proteolytic or gelatinase enzyme activity). Additionally, cell growth, acidification and bacteriocins production kinetics, bacteriocin stability in relation to different temperatures, pH and chemicals were evaluated. According to performed PCR all studied strains generated positive evidence for presence of entA and entP genes (for production of enterocins A and enterocins P, respectively). However, pediocin PA-1 associated gene were recorded only DNA from E. faecium ST02JL and Lc. garvieae ST04JL. CONCLUSIONS: It is worth considering the application of these safe LAB or their bacteriocins in situ as an alternative means of controlling L. monocytogenes in cheese production environments alone or in combination with other antimicrobials.

2.
Crit Rev Microbiol ; 49(5): 578-597, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35731254

RESUMO

There is almost a century since discovery of penicillin by Alexander Fleming, a century of enthusiasm, abuse, facing development of antibiotic-resistance and clear conclusion that the modern medicine needs a new type of antimicrobials. Bacteriocins produced by Gram-positive and Gram-negative bacteria, Archaea and Eukaryotes were widely explored as potential antimicrobials with several applications in food industry. In last two decades bacteriocins showed their potential as promising alternative therapeutic for the treatment of antibiotic-resistant pathogens. Bacteriocins can be characterised as highly selective antimicrobials and therapeutics with low cytotoxicity. Most probably in order to solve the problems associated with the increasing number of antibiotic-resistant bacteria, the application of natural or bioengineered bacteriocins in addition to synergistically acting preparations of bacteriocins and conventional antibiotics, can be the next step in combat versus drug-resistant pathogens. In this overview we focussed on diversity of specific lactic acid bacteria and their bacteriocins. Moreover, some additional examples of bacteriocins from non-lactic acid, Gram-positive and Gram-negative bacteria, Archaea and eukaryotic organisms are presented and discussed. Therapeutic properties of bacteriocins, their bioengineering and combined applications, together with conventional antibiotics, were evaluated with the scope of application in human and veterinary medicine for combating (multi-)drug-resistant pathogens.


Assuntos
Anti-Infecciosos , Bacteriocinas , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriocinas/farmacologia , Bacteriocinas/uso terapêutico , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Bactérias
3.
Foodborne Pathog Dis ; 20(7): 279-293, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37366658

RESUMO

Multidrug resistance in foodborne and clinical pathogens is a worldwide health problem. The urgent need for new alternatives to the existing antibiotics is emerging. Bacteriocin-like inhibitory substances can be considered part of the new generation of antimicrobials, which can be potentially applied in the food industry and health care practices. This study aimed to select Bacillus strains with antimicrobial activity against Staphylococcus spp. with future application in the formulation of pharmaceutical antimicrobial preparations. Putative antimicrobial agent-producing strains, previously isolated and preidentified as Bacillus spp. were profiled by repetitive element sequence-based polymerase chain reaction (rep-PCR) and 16s rRNA sequencing identified the strains as Bacillus tequilensis ST1962CD with 99.47% identity confidence and as Bacillus subtilis subsp. stercoris ST2056CD with 98.45% identity confidence. Both the selected Bacillus strains were evaluated via biomolecular and physiological approaches related to their safety and virulence, beneficial properties, enzyme production profile, and presence of corresponding genes for the production of antimicrobials and virulence. Both strains were confirmed to harbor srfa and sbo genes and be free of hemolysin binding component (B) and two lytic components (L1 and L2) [BL] and nonhemolytic enterotoxin-associated genes. Produced antimicrobial agents by strains ST1962CD and ST2056CD were partially purified through the combination of ammonium sulfate precipitation and hydrophobic-based chromatography on SepPakC18 and evaluated regarding their cytotoxicity. The dynamics of bacterial growth, pH change, accumulation of produced antimicrobials, and the mode of action were evaluated. Obtained results were pointing to the potential application of safe B. tequilensis ST1962CD and B. subtilis subsp. stercoris ST2056CD strains as functional beneficial microbial cultures that are putative producers of surfactin and/or subtilosin, as potent antimicrobials, for the treatment of some staphylococcal-associated infections. Expressed antimicrobials were shown to be not cytotoxic, and appropriate biotechnological approaches need to be developed for cost-effective production, isolation, and purification of expressed antimicrobials by studied strains.


Assuntos
Anti-Infecciosos , Bacillus , Bacteriocinas , Infecções Estafilocócicas , Humanos , Antibacterianos/farmacologia , Staphylococcus , RNA Ribossômico 16S/genética , Bacillus/genética , Bacillus/metabolismo , Bacteriocinas/farmacologia , Anti-Infecciosos/farmacologia , República da Coreia
4.
Crit Rev Microbiol ; 48(4): 513-530, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34620036

RESUMO

Representatives of the genus Bacillus are multifunctional microorganisms with a broad range of applications in both traditional fermentation and modern biotechnological processes. Bacillus spp. has several beneficial properties. They serve as starter cultures for various traditional fermented foods and are important biotechnological producers of enzymes, antibiotics, and bioactive peptides. They are also used as probiotics for humans, in veterinary medicine, and as feed additives for animals of agricultural importance. The beneficial effects of bacilli are well-reported and broadly acknowledged. However, with a better understanding of their positive role, many questions have been raised regarding their safety and the relevance of spore formation in the practical application of this group of microorganisms. What is the role of Bacillus spp. in the human microbial consortium? When and why did they start colonizing the gastrointestinal tract (GIT) of humans and other animals? Can spore-forming probiotics be considered as truly beneficial organisms, or should they still be approached with caution and regarded as "benefits with concerns"? In this review, we not only hope to answer the above questions but to expand the scope of the conversation surrounding bacilli probiotics.


Assuntos
Bacillus , Alimentos Fermentados , Probióticos , Animais , Bacillus/genética , Fermentação , Humanos , Esporos Bacterianos
5.
Crit Rev Toxicol ; 52(9): 731-741, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36757083

RESUMO

Mycotoxins in feedstuffs are considered as a principal worry by food safety authorities worldwide because most of them can be transferred from the feed to food commodities of animal origin, and further consumed by humans. Therefore, effective alternatives for the reduction of the impact of mycotoxins need to be applied in the feed production industry. Applications of beneficial microorganisms (probiotics) can be alternative and applied as feed additives in order to reduce or eliminate the toxic effects of mycotoxins on animals. The aim of this article is to provide information on the role of beneficial microorganisms (probiotics) and point out their role in the reduction of the effect of mycotoxin toxicity in farming animals (mammals and poultry). The objective was to provide a summary of the existing knowledge based on the application of different strains belonging to the group of lactic acid bacteria (LAB) or yeasts that are already or can be future employed in the feed industry, in order to reduce mycotoxicosis presence in mammals and poultry exposed to mycotoxin-contaminated feed. Moreover, an overview of mycotoxins toxicity in mammals and poultry will be presented, and furthermore, the role of the beneficial microorganisms (including probiotics) in the reduction of mycotoxins toxicity (aflatoxicosis, deoxynivalenol, zearalenone, ochratoxin A, and fumonisin toxicities) will be described in detail.


Assuntos
Micotoxicose , Micotoxinas , Probióticos , Animais , Humanos , Aves Domésticas , Contaminação de Alimentos , Micotoxinas/toxicidade , Mamíferos
6.
J Appl Microbiol ; 132(1): 311-330, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34231288

RESUMO

AIMS: The objective of this study was to isolate multifunctional bacteriocin-producing strains; to characterize the expressed bacteriocin for the control of Listeria monocytogenes and vancomycin-resistant Enterococcus; to evaluate the safety of studied strains; and to explore their antifungal activity. METHODS AND RESULTS: Two Pediococcus strains were isolated from silage samples obtained from an organic farm in Belogradchik, Bulgaria. The strains were identified by 16S rRNA sequencing analysis and characterized as bacteriocins producers. Strong antimicrobial activity was detected against more than 74 different strains of Listeria monocytogenes, 27 different vancomycin-resistant Enterococcus strains. In addition, studied strains were able to inhibit the growth of strains of Alternaria alternate, Aspergillus flavus, Aspergillus niger, Cladosporium sphaerospermum, Penicillium chrysogenum and Penicillium expansum. Some aspects of the antimicrobial mode of action were evaluated, including killing curves and aggregation properties. Both strains generated positive PCR results for the presence of pediocin PA-1, but not for other bacteriocins evaluated in this screening process. Metabolomic analysis of the cell-free supernatants from both strains was performed in order to explain the observed antifungal activity against different moulds. According to PCA and PLS-DA score plot, P. acidilactici ST3522BG and P. pentosaceus ST3633BG were clearly clustered from control (MRS). Increases in the production of benzoic acid, 2-hydroxyisocaproic acid, ß-phenyl-lactic acid, α-hydroxybutyric acid and 1,3-butanediol were recorded, these metabolites were previously described as antifungal. CONCLUSIONS: Pediococcus acidilactici ST3522BG and P. pentosaceus ST3633BG were evaluated as producing bacteriocin strains with high specificity against Listeria and vancomycin-resistant Enterococcus species. In addition, both investigated Pediococcus strains were evaluated as producer of effective antifungal metabolites with potential for the inhibition of mycotoxin-producing moulds. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this report is a pioneer in the evaluation of Pediococcus strains isolated from silage with highly specific bacteriocinogenic antimicrobial activity against Listeria spp. and vancomycin-resistant Enterococcus spp., and antifungal activity against mycotoxin-producing moulds.


Assuntos
Bacteriocinas , Listeria monocytogenes , Pediococcus acidilactici , Antibacterianos/farmacologia , Pediococcus , Pediococcus pentosaceus , RNA Ribossômico 16S/genética , Silagem
7.
Food Microbiol ; 102: 103886, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809929

RESUMO

Enterococcus faecium ST20Kc and ST41Kc were isolated from kimchi, a traditional Korean fermented cabbage. Bacteriocins produced by both strains exhibited strong activity against Listeria monocytogenes and various Enterococcus spp., including 30 vancomycin-resistant enterococcal strains, but not against other lactic acid bacteria (LAB) on the evaluated test panel. The antimicrobials produced by the strains were found to be proteinaceous and stable even after exposure to varying pH, temperature, and chemicals used in the industry and laboratory processes. Antimicrobial activity of both strains was evaluated as bactericidal against exponentially growing cultures of L. monocytogenes ATCC® 15313™ and Enterococcus faecalis 200A. Based on tricine-SDS-PAGE, the molecular weights of the bacteriocins produced by the strains were between 4 and 6 kDa. Additionally, both strains were susceptible to antibiotics, including vancomycin, kanamycin, gentamycin, ampicillin, streptomycin, tylosin, chloramphenicol, clindamycin, and tetracycline. Adhesion genes, map, mub, and EF-Tu, were also detected in the genomes of both strains. With gastrointestinal stress induction, both strains showed high individual survival rates, and capability to reduce viable counts of L. monocytogenes ATCC® 15313™ and Enterococcus faecalis 200A in mixed cultures. Based on the metabolomics analysis, both strains were found to produce additional antimicrobial compounds, particularly, lactic acid, phenyllactic acid, and phenethylamine, which can be potentially involved in the antimicrobial interaction with pathogenic microorganisms.


Assuntos
Antibacterianos , Bacteriocinas , Brassica , Enterococcus faecium , Alimentos Fermentados , Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Brassica/microbiologia , Hidrocarbonetos Aromáticos com Pontes , Enterococcus faecalis , Alimentos Fermentados/microbiologia , Listeria monocytogenes , Testes de Sensibilidade Microbiana , República da Coreia
8.
World J Microbiol Biotechnol ; 39(1): 4, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36344843

RESUMO

Pediococci are lactic acid bacteria (LAB) which have been used for centuries in the production of traditional fermented foods. There fermentative abilities were explored by the modern food processing industry in use of pediococci as starter cultures, enabling the production of fermented foods with distinct characteristics. Furthermore, some pediococci strains can produce bacteriocins and other antimicrobial metabolites (AMM), such as pediocins, which are increasingly being explored as bio-preservatives in various food matrices. Due to their versatility and inhibitory spectrum, pediococci bacteriocins and AMM are being extensively researched not only in the food industry, but also in veterinary and human medicine. Some of the pediococci were evaluated as potential probiotics with different beneficial areas of application associated with human and other animals' health. The main taxonomic characteristics of pediococci species are presented here, as well as and their potential roles and applications as starter cultures, as bio-preservatives and as probiotic candidates.


Assuntos
Bacteriocinas , Lactobacillales , Probióticos , Animais , Humanos , Pediococcus , Probióticos/metabolismo , Bacteriocinas/metabolismo , Lactobacillales/metabolismo , Pediocinas , Fermentação , Antibacterianos/farmacologia , Microbiologia de Alimentos
9.
BMC Microbiol ; 19(1): 63, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894128

RESUMO

BACKGROUND: Bacteriocins produced by lactic acid bacteria (LAB) can be considered as viable alternatives for food safety and quality, once these peptides present antimicrobial activity against foodborne pathogens and spoilage bacteria. Fermented foods, such as artisanal sausages and cured meats, are relevant sources of LAB strains capable of producing novel bacteriocins, with particular interest by the food industry. RESULTS: Three LAB strains (firstly named as Lactobacillus curvatus 12, L. curvatus 36 and Weissella viridescens 23) were obtained from calabresa by presenting promising bacteriocinogenic activity, distinct genetic profiles (rep-PCR, RAPD, bacteriocin-related genes) and wide inhibitory spectrum. Among these strains, L. curvatus 12 presented higher bacteriocin production, reaching 25,000 AU/mL after incubation at 25, 30 and 37 °C and 6, 9 and 12 h. Partially purified bacteriocins from L. curvatus 12 kept their inhibitory activity after elution with isopropanol at 60% (v/v). Bacteriocins produced by this strain were purified by HPLC and sequenced, resulting in four peptides with 3102.79, 2631.40, 1967.06 and 2588.31 Da, without homology to known bacteriocins. CONCLUSIONS: LAB isolates obtained from calabresa presented high inhibitory activity. Among these isolates, bacteriocins produced by L. curvatus 12, now named as L. curvatus UFV-NPAC1, presented the highest inhibitory performance and the purification procedures revealed four peptides with sequences not described for bacteriocins to date.


Assuntos
Antibiose , Bacteriocinas/isolamento & purificação , Alimentos Fermentados/microbiologia , Lactobacillales/química , Lactobacillus/química , Listeria monocytogenes , Produtos da Carne/microbiologia , Bacteriocinas/genética , Meios de Cultura , Microbiologia de Alimentos , Lactobacillales/isolamento & purificação , Lactobacillus/isolamento & purificação
10.
J Food Sci Technol ; 56(11): 5128-5137, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31741537

RESUMO

The aim of this study was to isolate Enterococcus faecium from raw milk samples, to characterize its antimicrobial metabolites, and to evaluate its viability in a probiotic Minas Frescal cheese. For this, antagonist activity against Listeria monocytogenes, safety aspects and biochemical, genotypic, and probiotic characteristics of the isolates were evaluated. Minas Frescal cheese was manufactured with the isolate that showed the best characteristics in vitro, and its viability in the product was evaluated. It was observed that of the 478 lactic acid bacteria isolates, only isolate E297 presented antagonist activity, genes encoding for enterocin production and absence of virulence factors. Besides that, E297 presented probiotic characteristics in vitro, and maintained its viability (8.09 log CFU mL-1) for 14 days of cold storage, when it was added to cheese. Therefore, isolate E297 can be considered a promising microorganism for the manufacture of probiotic foods, especially Minas Frescal cheese.

11.
J Dairy Res ; 85(4): 487-496, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30444209

RESUMO

Scientific studies demonstrate the importance of intestinal microbiota to human health and how probiotic microorganisms can positively affect health when administered regularly and in adequate amounts. Probiotic bacteria can be part of fermented products and their functional importance is associated mainly with their metabolism. They are thought to benefit individuals to maintain their health and also to strengthen resistance against various types of diseases. The acceptance of probiotic cultures and products by consumers increased when these bacteria were marketed as natural cultures that help in digestion and health. Considering this, the food industry has an increasing demand for new candidates as probiotic cultures, and the dairy industry has a particular interest for fermented milks and other dairy products, since these are the most common food vehicles for probiotic cultures. Therefore, the dairy industries are increasingly seeking to improve their products with these beneficial bacteria. However, the legal peculiarities and excess of control agencies in Brazil makes the registration of these products and the collection of data very complex. Prospective analysis suggests that probiotic foods have the potential to effect a considerable expansion of the dairy industry, allowing the dairy sector to grow and for these products to be increasingly sought by consumers globally. For this, not only actions on research and innovation are necessary, but also official clarifications on the claims for considerations of microbiological security and functionality of these products. This review aims to elucidate important probiotic research regarding the isolation and characterization of beneficial cultures in Brazil, and to demonstrate the relevance of the dairy chain as a potential source of novel cultures for the development of new probiotic products to expand the Brazilian dairy industry.


Assuntos
Bactérias/classificação , Bactérias/metabolismo , Laticínios/microbiologia , Leite/microbiologia , Probióticos , Animais , Brasil , Bovinos , Microbiologia de Alimentos , Humanos
12.
Antonie Van Leeuwenhoek ; 109(9): 1271-80, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27255139

RESUMO

Different strains of Lactococcus lactis are capable of producing the bacteriocin nisin. However, genetic transfer mechanisms allow the natural occurrence of genes involved in nisin production in members of other bacterial genera, such as Enterococcus spp. In a previous study, nisA was identified in eight enterococci capable of producing antimicrobial substances. The aim of this study was to verify the presence of genes involved in nisin production in Enterococcus spp. strains, as well as nisin expression. The nisA genes from eight Enterococcus spp. strains were sequenced and the translated amino acid sequences were compared to nisin amino-acid sequences previously described in databases. Although containing nisin structural and maturation related genes, the enterococci strains tested in the present study did not present the immunity related genes (nisFEG and nisI). The translated sequences of nisA showed some point mutations, identical to those presented by Lactococcus strains isolated from goat milk. All enterococci were inhibited by nisin, indicating the absence of immunity and thus that nisin cannot be expressed. This study demonstrated for the first time the natural occurrence of nisin structural genes in Enterococcus strains and highlights the importance of providing evidence of a link between the presence of bacteriocin genes and their expression.


Assuntos
Enterococcus/genética , Enterococcus/metabolismo , Genes Bacterianos , Leite/microbiologia , Nisina/biossíntese , Nisina/genética , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Sequência de Bases , DNA Bacteriano/genética , Enterococcus/isolamento & purificação , Cabras , Mutação , Nisina/metabolismo , Análise de Sequência
13.
Food Microbiol ; 46: 254-262, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25475294

RESUMO

The aims of this study were to isolate LAB with anti-Listeria activity from salami samples, characterize the bacteriocin/s produced by selected isolates, semi-purify them and evaluate their effectiveness for the control of Listeria monocytogenes during manufacturing of salami in a pilot scale. Two isolates (differentiated by RAPD-PCR) presented activity against 22 out of 23 L. monocytogenes strains for bacteriocin MBSa2, while the bacteriocin MBSa3 inhibited all 23 strains in addition to several other Gram-positive bacteria for both antimicrobials and were identified as Lactobacillus curvatus based on 16S rRNA sequencing. A three-step purification procedure indicated that both strains produced the same two active peptides (4457.9 Da and 4360.1 Da), homlogous to sakacins P and X, respectively. Addition of the semi-purified bacteriocins produced by Lb. curvatus MBSa2 to the batter for production of salami, experimentally contaminated with L. monocytogenes (10(4)-10(5) CFU/g), caused 2 log and 1.5 log reductions in the counts of the pathogen in the product after 10 and 20 days respectively, highlighting the interest for application of these bacteriocins to improve safety of salami during its manufacture.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Aditivos Alimentares/farmacologia , Conservação de Alimentos/métodos , Lactobacillus/química , Produtos da Carne/microbiologia , Animais , Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Aditivos Alimentares/metabolismo , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Lactobacillus/metabolismo , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Suínos
14.
Food Microbiol ; 48: 143-52, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25791002

RESUMO

Survival, bacteriocin(s) production, and antilisterial effect of Lactobacillus sakei subsp. sakei 2a were evaluated in a potentially synbiotic cheese spread, throughout storage at 4 °C and 15 °C for up to 28 days, using culture-dependent (plate count) and culture-independent (qPCR) methods. Bacteriocin(s) production in the food product was monitored by phenotypic and molecular (RT-qPCR) techniques. Three cheese spread trials (T) containing the prebiotic fiber inulin were produced in duplicates and studied: T1 (control - without inoculation of lactic acid bacteria); T2 (inoculated with the non-bacteriocinogenic Lb. sakei ATCC 15521 strain), and T3 (inoculated with the bacteriocinogenic Lb. sakei 2a strain). The cheese spreads were challenged with Listeria monocytogenes serotypes 4b and 1/2a, individually added to the food product. The counts of Lb. sakei 2a in the cheese spread T3 remained high during storage and the growth of L. monocytogenes was inhibited at both temperatures, especially L. monocytogenes 4b in the food product kept at 15 °C due to the production of bacteriocins (up to 6,400 AU/mL). Expression of the genes sakP and sakQ encoding for bacteriocins production during the cheese spread storage was demonstrated. Lb. sakei 2a can be used for production of potentially synbiotic cheese spreads with increased safety.


Assuntos
Bacteriocinas/metabolismo , Queijo/microbiologia , Lactobacillus/metabolismo , Listeria monocytogenes/crescimento & desenvolvimento , Simbióticos/análise , Bacteriocinas/farmacologia , Lactobacillus/genética , Listeria monocytogenes/efeitos dos fármacos
15.
Food Microbiol ; 38: 228-39, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24290647

RESUMO

Four LAB strains, isolated from Bulgarian home made white brine cheese, were selected for their effective inhibition against Listeria monocytogenes. According to their biochemical and physiological characteristics, the strains were classified as members of Enterococcus genus, and then identified as Enterococcus faecium by 16S rDNA sequencing. Their bacteriocin production and inhibitory spectrum were evaluated together with the occurrence of several bacteriocin genes (entA, entB, entP, entL50B). Their virulence potential and safety was assessed both using PCR targeted to the genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc and by phenotypical tests for antibiotic resistance, gelatinase, lipase, DNAse and α- and ß-haemolysis. The E. faecium strains harboured at least one enterocin gene while the occurrence of virulence, antibiotic resistance and biogenic amines genes was limited. Considering their strong antimicrobial activity against L. monocytogenes strains, the four E. faecium strains exhibited promising potential as bio-preservatives cultures for fermented food productions.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/biossíntese , Bacteriocinas/farmacologia , Queijo/microbiologia , Enterococcus faecium/metabolismo , Antibacterianos/biossíntese , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Enterococcus faecium/química , Enterococcus faecium/isolamento & purificação , Listeria monocytogenes/efeitos dos fármacos , Sais/análise
16.
Food Microbiol ; 44: 296-301, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25084676

RESUMO

Charqui is a fermented, salted and sun-dried meat product, widely consumed in Brazil and exported to several countries. Growth of microorganisms in this product is unlikely due to reduced Aw, but halophilic and halotolerant bacteria may grow and cause spoilage. Charqui is a good source of lactic acid bacteria able to produce antimicrobial bacteriocins. In this study, an autochthonous bacteriocinogenic strain (Lactococcus lactis subsp. lactis 69), isolated from charqui, was added to the meat used for charqui manufacture and evaluated for its capability to prevent the growth of spoilage bacteria during storage up to 45 days. The influence of L. lactis 69 on the bacterial diversity during the manufacturing of the product was also studied, using denaturing gradient gel electrophoresis (DGGE). L. lactis 69 did not affect the counts and diversity of lactic acid bacteria during manufacturing and storage, but influenced negatively the populations of halotolerant microorganisms, reducing the spoilage potential. The majority of tested virulence genes was absent, evidencing the safety and potential technological application of this strain as an additional hurdle to inhibit undesirable microbial growth in this and similar fermented meat products.


Assuntos
Bactérias/crescimento & desenvolvimento , Bacteriocinas/metabolismo , Biodiversidade , Conservação de Alimentos/métodos , Lactococcus lactis/metabolismo , Produtos da Carne/microbiologia , Cloreto de Sódio/metabolismo , Animais , Bactérias/isolamento & purificação , Bactérias/metabolismo , Brasil , Fermentação , Lactococcus lactis/genética , Suínos
17.
Foods ; 13(12)2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38928759

RESUMO

Fermentation is probably the oldest ancient tradition used by indigenous inhabitants for the preservation of food [...].

18.
Probiotics Antimicrob Proteins ; 16(2): 696-697, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38324140

RESUMO

It has become a tradition for the BAMP (Bacteriocins and Antimicrobial Peptides) symposium to be a part of the IPC (International Probiotic Conference). In 2024, IPC/BAMP will be held on the 18th-20th of June in Prague, Czech Republic ( www.probiotic-conference.net ) and will reunite scientists, students, and representatives from industry and regulations agencies from all around the world. The meeting will serve as a platform for the exchange of knowledge and ideas regarding the past, present, and future of beneficial microbes, probiotics, antimicrobials, and proteins, and their influence on a prosperous and healthier future.


Assuntos
Anti-Infecciosos , Bacteriocinas , Probióticos , Humanos , Bacteriocinas/farmacologia , Bacteriocinas/metabolismo , Probióticos/metabolismo , Anti-Infecciosos/farmacologia
19.
Probiotics Antimicrob Proteins ; 16(2): 394-412, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36928486

RESUMO

Strain ST3Ha, isolated from commercially available smoked salmon, was identified as Pediococcus pentosaceus based on biochemical and physiological tests and 16S rRNA sequencing. Strain ST3Ha produces a class IIa bacteriocin active against lactic acid bacteria, Listeria monocytogenes and Enterococcus faecalis. The antimicrobial peptide was inactivated by proteolytic enzymes, confirming his proteinaceous nature, but was not affected when treated with α-amylase, SDS, Tween 20, Tween 80, urea, and EDTA. No change in activity was recorded after 2 h at pH values between 2.0 and 9.0 and after treatment at 100 °C for 120 min or 121 °C for 15 min. The mode of action against Listeria ivanovii subsp. ivanovii ATCC 19119 and E. faecalis ATCC 19443 was bactericidal, resulting in cell lyses and enzyme leakage. The highest level of activity (1.6 × 106 AU/mL) was recorded when cells were grown at 37 °C or 30 °C in MRS broth (pH 6.5). Antimicrobial peptide ST3Ha adsorbs at high levels to the sensitive test organisms on strain-specific manner and depending on incubation temperature, environmental pH, and presence of supplemented chemicals. Based on PCR analysis, P. pentosaceus ST3Ha harbor a 1044-bp plasmid-associated fragment corresponding in size to that recorded for pediocin PA-1. Sequencing of the fragment revealed a gene identical to pedB, reported for pediocin PA-1. The combined application of the low levels (below MIC) of ciprofloxacin and bacteriocin ST3Ha results in the synergetic effect in the inhibition of L. ivanovii subsp. ivanovii ATCC 19119. Expressed by P. pentosaceus ST3Ha, bacteriocin was characterized as low cytotoxic, a characteristic relevant for its application in food industry and/or in human and veterinary medical practices.


Assuntos
Bacteriocinas , Listeria , Humanos , Animais , Bacteriocinas/genética , Bacteriocinas/farmacologia , Bacteriocinas/química , Pediococcus pentosaceus/genética , RNA Ribossômico 16S/genética , Pediococcus , Antibacterianos/farmacologia , Plasmídeos , Salmão/microbiologia , Peptídeos Antimicrobianos
20.
Insects ; 15(6)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38921144

RESUMO

Bees are one of the best-known and, at the same time, perhaps the most enigmatic insects on our planet, known for their organization and social structure, being essential for the pollination of agricultural crops and several other plants, playing an essential role in food production and the balance of ecosystems, being associated with the production of high-value-added inputs, and a unique universe in relation to bees' microbiota. In this review, we summarize information regarding on different varieties of bees, with emphasis on their specificity related to microbial variations. Noteworthy are fructophilic bacteria, a lesser-known bacterial group, which use fructose fermentation as their main source of energy, with some strains being closely related to bees' health status. The beneficial properties of fructophilic bacteria may be extendable to humans and other animals as probiotics. In addition, their biotechnological potential may ease the development of new-generation antimicrobials with applications in biopreservation. The concept of "One Health" brings together fundamental and applied research with the aim of clarifying that the connections between the different components of ecosystems must be considered part of a mega-structure, with bees being an iconic example in that the healthy functionality of their microbiota is directly and indirectly related to agricultural production, bee health, quality of bee products, and the functional prosperity for humans and other animals. In fact, good health of bees is clearly related to the stable functionality of ecosystems and indirectly relates to humans' wellbeing, a concept of the "One Health".

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