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1.
Antibiotics (Basel) ; 13(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38786143

RESUMO

This review delves into using natural antimicrobials in the dairy industry and examines various sources of these compounds, including microbial, plant, and animal sources. It discusses the mechanisms by which they inhibit microbial growth, for example, by binding to the cell wall's precursor molecule of the target microorganism, consequently inhibiting its biosynthesis, and interfering in the molecule transport mechanism, leading to cell death. In general, they prove to be effective against the main pathogens and spoilage found in food, such as Escherichia coli, Staphylococcus aureus, Bacillus spp., Salmonella spp., mold, and yeast. Moreover, this review explores encapsulation technology as a promising approach for increasing the viability of natural antimicrobials against unfavorable conditions such as pH, temperature, and oxygen exposure. Finally, this review examines the benefits and challenges of using natural antimicrobials in dairy products. While natural antimicrobials offer several advantages, including improved safety, quality, and sensory properties of dairy products, it is crucial to be aware of the challenges associated with their use, such as potential allergenicity, regulatory requirements, and consumer perception. This review concludes by emphasizing the need for further research to identify and develop effective and safe natural antimicrobials for the dairy industry to ensure the quality and safety of dairy products for consumers.

2.
FEMS Microbes ; 5: xtae005, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476864

RESUMO

Antimicrobial resistance has been considered a public health threat. The World Health Organization has warned about the urgency of detecting new antibiotics from novel sources. Social insects could be crucial in the search for new antibiotic metabolites, as some of them survive in places that favor parasite development. Recent studies have shown the potential of social insects to produce antimicrobial metabolites (e.g. ants, bees, and termites). However, most groups of social wasps remain unstudied. Here, we explored whether Actinobacteria are associated with workers in the Neotropical Social Wasps (Epiponini) of Costa Rica and evaluated their putative inhibitory activity against other bacteria. Most isolated strains (67%) have antagonistic effects, mainly against Bacillus thuringensis and Escherichia coli ATCC 25992. Based on genome analysis, some inhibitory Actinobacteria showed biosynthetic gene clusters (BGCs) related to the production of antimicrobial molecules such as Selvamycin, Piericidin A1, and Nystatin. The Actinobacteria could be associated with social wasps to produce antimicrobial compounds. For these reasons, we speculate that Actinobacteria associated with social wasps could be a novel source of antimicrobial compounds, mainly against Gram-negative bacteria.

3.
Artigo em Inglês | MEDLINE | ID: mdl-37572214

RESUMO

The food industry has been developing new products with health benefits, extended shelf life, and without chemical preservation. Bacteriocin-producing lactic acid bacteria (LAB) strains have been evaluated for food fermentation to prevent contamination and increase shelf life. In this study, potentially probiotic LAB strains, Lactiplantibacillus (Lb.) plantarum ST8Sh, Lacticaseibacillus (Lb.) casei SJRP38, and commercial starter Streptococcus (St.) thermophilus ST080, were evaluated for their production of antimicrobial compounds, lactic acid and enzyme production, carbohydrate assimilation, and susceptibility to antibiotics. The characterization of antimicrobial compounds, the proteolytic activity, and its inhibitory property against Listeria (List.) monocytogenes and Staphylococcus (Staph.) spp. was evaluated in buriti and passion fruit-supplemented fermented milk formulations (FMF) produced with LAB strains. Lb. plantarum ST8Sh was found to inhibit List. monocytogenes through bacteriocin production and produced both L(+) and D(-) lactic acid isomers, while Lb. casei SJRP38 mainly produced L(+) lactic acid. The carbohydrate assimilation profiles were compatible with those usually found in LAB. The potentially probiotic strains were susceptible to streptomycin and tobramycin, while Lb. plantarum ST8Sh was also susceptible to ciprofloxacin. All FMF produced high amounts of L(+) lactic acid and the viability of total lactobacilli remained higher than 8.5 log CFU/mL during monitored storage period. Staph. aureus ATCC 43300 in fermented milk with passion fruit pulp (FMFP) and fermented milk with buriti pulp (FMB), and Staph. epidermidis KACC 13234 in all formulations were completely inhibited after 14 days of storage. The combination of Lb. plantarum ST8Sh and Lb. casei SJRP38 and fruit pulps can provide increased safety and shelf-life for fermented products, and natural food preservation meets the trends of the food market.

4.
Int J Biol Macromol ; 233: 123418, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36731700

RESUMO

Interest is growing in entrapping natural antimicrobial compounds (NACs) within polyhydroxyalkanoates (PHAs) to produce active food-biopackaging systems. PHAs are versatile polymeric macromolecules that can protect NAC activity by entrapment. This work reviews 75 original papers and 18 patents published in the last 11 years concerning PHAs as matrices for NACs to summarize the physicochemical properties, release, and antimicrobial activities of systems fabricated from PHAs and NACs (PHA/NAC systems). PHA/NAC systems have recently been used as active food biopackaging systems to inactivate foodborne pathogens and prolong food shelf life. PHAs protect NACs by increasing the degradation temperature of some NACs and decreasing their loss of mass when heated. Some NACs also transform the PHA/NAC systems into more thermostable, flexible, and resistant when interacting with PHAs while also improving the barrier properties of the systems. NAC release and activity are also prolonged when NACs are trapped within PHAs. PHA/NAC systems, therefore, represent ecologically friendly materials with promising applications.


Assuntos
Anti-Infecciosos , Poli-Hidroxialcanoatos , Poli-Hidroxialcanoatos/química , Anti-Infecciosos/farmacologia , Armazenamento de Alimentos
5.
World J Microbiol Biotechnol ; 38(7): 114, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35578144

RESUMO

Burkholderia ambifaria T16 is a bacterium isolated from the rhizosphere of barley plants that showed a remarkable antifungal activity. This strain was also able to degrade fusaric acid (5-Butylpyridine-2-carboxylic acid) and detoxify this mycotoxin in inoculated barley seedlings. Genes and enzymes responsible for fusaric acid degradation have an important biotechnological potential in the control of fungal diseases caused by fusaric acid producers, or in the biodegradation/bio catalysis processes of pyridine derivatives. In this study, the complete genome of B. ambifaria T16 was sequenced and analyzed to identify genes involved in survival and competition in the rhizosphere, plant growth promotion, fungal growth inhibition, and degradation of aromatic compounds. The genomic analysis revealed the presence of several operons for the biosynthesis of antimicrobial compounds, such as pyrrolnitrin, ornibactin, occidiofungin and the membrane-associated AFC-BC11. These compounds were also detected in bacterial culture supernatants by mass spectrometry analysis. In addition, this strain has multiple genes contributing to its plant growth-promoting profile, including those for acetoin, 2,3-butanediol and indole-3-acetic acid production, siderophores biosynthesis, and solubilisation of organic and inorganic phosphate. A pan-genomic analysis demonstrated that the genome of strain T16 possesses large gene clusters that are absent in the genomes of B. ambifaria reference strains. According to predictions, most of these clusters would be involved in aromatic compounds degradation. One genomic region, encoding flavin-dependent monooxygenases of unknown function, is proposed as a candidate responsible for fusaric acid degradation.


Assuntos
Anti-Infecciosos , Complexo Burkholderia cepacia , Burkholderia , Micotoxinas , Anti-Infecciosos/metabolismo , Burkholderia/metabolismo , Complexo Burkholderia cepacia/genética , Ácido Fusárico/metabolismo , Genoma Bacteriano , Micotoxinas/metabolismo
6.
Future Microbiol ; 17: 701-716, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35392662

RESUMO

With the increase in resistance to conventional antibiotics among bacterial pathogens, the search for new antimicrobials becomes more and more necessary. Although most studies focus on the discovery of antimicrobial peptides for the development of new antibiotics, several others in the literature have described polysaccharides with the same biological activity with the potential for use as therapeutic alternatives. Here we review the currently available literature on antimicrobial polysaccharides isolated from different sources to demonstrate that there are several possible unconventional carbohydrate polymers that could act as therapeutic alternatives in the battle against drug-resistant pathogens.


Assuntos
Anti-Infecciosos , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bactérias , Polissacarídeos/farmacologia
7.
Antibiotics (Basel) ; 11(2)2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35203761

RESUMO

Due to the rapid mutation of pathogenic microorganisms, drug-resistant superbugs have evolved. Antimicrobial-resistant germs may share their resistance genes with other germs, making them untreatable. The search for more combative antibiotic compounds has led researchers to explore metal-based strategies centered on perturbing the bioavailability of essential metals in microbes and examining the therapeutic potential of metal complexes. Given the limited knowledge on the application of titanium(IV), in this work, eight Ti(IV) complexes and some of their corresponding ligands were screened by the Community for Open Antimicrobial Drug Discovery for antimicrobial activity. The compounds were selected for evaluation because of their low cytotoxic/antiproliferative behavior against a human non-cancer cell line. At pH 7.4, these compounds vary in terms of their solution stability and ligand exchange lability; therefore, an assessment of their solution behavior provides some insight regarding the importance of the identity of the metal compound to the antimicrobial therapeutic potential. Only one compound, Ti(deferasirox)2, exhibited promising inhibitory activity against the Gram-positive bacteria methicillin-resistant Staphylococcus aureus and minimal toxicity against human cells. The ability of this compound to undergo transmetalation with labile Fe(III) sources and, as a consequence, inhibit Fe bioavailability and ribonucleotide reductase is evaluated as a possible mechanism for its antibiotic effect.

8.
J Venom Anim Toxins Incl Trop Dis ; 26: e20200023, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33193751

RESUMO

BACKGROUND: Endemic systemic mycoses remain a health challenge, since these opportunistic diseases are increasingly infecting immunosuppressed patients. The simultaneous use of antifungal compounds and other drugs to treat infectious or non-infectious diseases has led to several interactions and undesirable effects. Thus, new antifungal compounds should be investigated. The present study aimed to evaluate the activity of liriodenine extracted from Annona macroprophyllata on agents of systemic mycoses, with emphasis on the genus Paracoccidioides. METHODS: The minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined by the microdilution method. The cellular alterations caused by liriodenine on a standard P. brasiliensis (Pb18) strain were evaluated by transmission and scanning electron microscopy. RESULTS: Liriodenine was effective only in 3 of the 8 strains of the genus Paracoccidioides and in the Histoplasma capsulatum strain, in a very low concentration (MIC of 1.95 µg.mL-1); on yeasts of Candida spp. (MIC of 125 to 250 µg.mL-1), including C. krusei (250 µg.mL-1), which has intrinsic resistance to fluconazole; and in Cryptococcus neoformans and Cryptococcus gattii (MIC of 62.5 µg.mL-1). However, liriodenine was not effective against Aspergillus fumigatus at the studied concentrations. Liriodenine exhibited fungicidal activity against all standard strains and clinical isolates that showed to be susceptible by in vitro tests. Electron microscopy revealed cytoplasmic alterations and damage to the cell wall of P. brasiliensis (Pb18). CONCLUSION: Our results indicate that liriodenine is a promising fungicidal compound that should undergo further investigation with some chemical modifications.

9.
Front Microbiol ; 11: 990, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32528438

RESUMO

The emergence of bacterial strains resistant to different antibiotics has prompted the search for new sources of antimicrobial compounds. Studies have shown that jambolan [Syzygium cumini (L.) Skeels], a tropical fruit from the Mirtaceae family, contains a great variety of phytochemical compounds with high antioxidant and antimicrobial activity. This study aimed to determine the centesimal composition and physicochemical characteristics of the pulp and seed of S. cumini (L.) Skeels, as well as the content of total phenolic compounds and the antioxidant, antibacterial, antibiofilm and anti-quorum sensing (QS) activities of the phenolic extracts obtained from the pulp and the seeds of this fruit. The in vitro antibacterial and anti-QS activities of active films incorporating phenolic extracts were also evaluated. Additionally, we performed molecular docking of phenolic compounds present in jambolan with the CviR QS regulator of Chromobacterium violaceum. The composition and physicochemical characteristics of the samples presented similar values to those found for the species. However, the seed phenolic extract had a higher content of phenolic compounds and antioxidant activity than the pulp. Both phenolic extracts presented antibacterial activity against Aeromonas hydrophila, C. violaceum, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Serratia marcescens, Listeria monocytogenes, and Staphylococcus aureus. The seed phenolic extract was particularly inhibitory against S. aureus. The pulp phenolic extract inhibited swarming motility and biofilm formation of A. hydrophila, E. coli, and S. marcescens in sub-MIC concentrations. The pulp and seed phenolic extracts inhibited violacein production in C. violaceum. Films incorporating both phenolic extracts inhibited the growth of bacteria, particularly Pseudomonas fluorescens, L. monocytogenes, and S. aureus, as well as QS in C. violaceum. Molecular docking showed that a variety of compounds found in pulp and seed extracts of jambolan, particularly chlorogenic acid and dihydroquercetin, potentially bind CviR protein and may interfere with QS. Our results indicate that pulp and seed of jambolan are good sources of antibacterial, antibiofilm, and anti-QS compounds that can be used in the development of natural preservatives and for application in antibacterial active films.

10.
Plants (Basel) ; 9(2)2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32041311

RESUMO

This study evaluates the antimicrobial and antifungal potential of the essential oil extracted from a species located in the Andes of Ecuador, Piper barbatum Kunth, known as "cordoncillo" or "allupa", used by the Quichua people as an antibacterial plant for washing female genitalia in cases of infection. The most abundant molecules in the essential oil were: α- phellandrene (43.16%), limonene (7.04%); some oxygenated sesquiterpenes such as: trans-sesquisabinene hydrate (8.23%), elemol (7.21%) and others. The evaluation of antimicrobial activity showed activity in all the strains analyzed; however, those in which MIC values are considered to be very strong (less than 500 µg/mL) are: Staphylococcus aureus 264 µg/mL, Streptococcus mutans 132 µg/mL, Candida albicans 132 µg/mL and Candida tropicalis 264 µg/mL. Antimicrobial bioautography defines which molecules are responsible for the activity; thus, it was possible to establish the chromatographic regions of = 0.02 and Rf = 0.04, as those with active molecules. It was established that 4 hydroxylated sesquiterpene molecules are involved: elemol (7.21%), trans-sesquisabinene hydrate (8.23%), ß-eudesmol (3.49%) and 10-epi-γ-eudesmol (1.07%); the last two being the most active. The aim of this manuscript is to analyze both the ancestral knowledge of the Quichua people of Ecuador, and the chemical-biodiversity of the Andean forest ecosystem, in order to provide new raw materials of pharmaceutical interest.

11.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 26: e20200023, 2020. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-32274

RESUMO

Endemic systemic mycoses remain a health challenge, since these opportunistic diseases are increasingly infecting immunosuppressed patients. The simultaneous use of antifungal compounds and other drugs to treat infectious or non-infectious diseases has led to several interactions and undesirable effects. Thus, new antifungal compounds should be investigated. The present study aimed to evaluate the activity of liriodenine extracted from Annona macroprophyllata on agents of systemic mycoses, with emphasis on the genus Paracoccidioides. Methods: The minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined by the microdilution method. The cellular alterations caused by liriodenine on a standard P. brasiliensis (Pb18) strain were evaluated by transmission and scanning electron microscopy. Results: Liriodenine was effective only in 3 of the 8 strains of the genus Paracoccidioides and in the Histoplasma capsulatum strain, in a very low concentration (MIC of 1.95 µg.mL-1); on yeasts of Candida spp. (MIC of 125 to 250 µg.mL-1), including C. krusei (250 µg.mL-1), which has intrinsic resistance to fluconazole; and in Cryptococcus neoformans and Cryptococcus gattii (MIC of 62.5 µg.mL-1). However, liriodenine was not effective against Aspergillus fumigatus at the studied concentrations. Liriodenine exhibited fungicidal activity against all standard strains and clinical isolates that showed to be susceptible by in vitro tests. Electron microscopy revealed cytoplasmic alterations and damage to the cell wall of P. brasiliensis (Pb18). Conclusion: Our results indicate that liriodenine is a promising fungicidal compound that should undergo further investigation with some chemical modifications.(AU)


Assuntos
Antifúngicos/análise , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Micoses/diagnóstico , Micoses/microbiologia , Anti-Infecciosos , Paracoccidioides
12.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;26: e20200023, 2020. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1135136

RESUMO

Endemic systemic mycoses remain a health challenge, since these opportunistic diseases are increasingly infecting immunosuppressed patients. The simultaneous use of antifungal compounds and other drugs to treat infectious or non-infectious diseases has led to several interactions and undesirable effects. Thus, new antifungal compounds should be investigated. The present study aimed to evaluate the activity of liriodenine extracted from Annona macroprophyllata on agents of systemic mycoses, with emphasis on the genus Paracoccidioides. Methods: The minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined by the microdilution method. The cellular alterations caused by liriodenine on a standard P. brasiliensis (Pb18) strain were evaluated by transmission and scanning electron microscopy. Results: Liriodenine was effective only in 3 of the 8 strains of the genus Paracoccidioides and in the Histoplasma capsulatum strain, in a very low concentration (MIC of 1.95 µg.mL-1); on yeasts of Candida spp. (MIC of 125 to 250 µg.mL-1), including C. krusei (250 µg.mL-1), which has intrinsic resistance to fluconazole; and in Cryptococcus neoformans and Cryptococcus gattii (MIC of 62.5 µg.mL-1). However, liriodenine was not effective against Aspergillus fumigatus at the studied concentrations. Liriodenine exhibited fungicidal activity against all standard strains and clinical isolates that showed to be susceptible by in vitro tests. Electron microscopy revealed cytoplasmic alterations and damage to the cell wall of P. brasiliensis (Pb18). Conclusion: Our results indicate that liriodenine is a promising fungicidal compound that should undergo further investigation with some chemical modifications.(AU)


Assuntos
Paracoccidioides , Microscopia Eletrônica , Testes de Sensibilidade Microbiana , Cryptococcus neoformans , Cryptococcus gattii , Micoses , Antifúngicos/isolamento & purificação
13.
Bioprocess Biosyst Eng ; 42(8): 1325-1332, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31028462

RESUMO

Basidiomycetes fungi have been utilized for the production of several compounds with bioactive properties, such as phenolic compounds. The present work quantified and identified the phenolic compounds produced in a kinetic study (63 days) and evaluated the antimicrobial activity from the extract obtained by Ganoderma lipsiense cultivation in solid-state fermentation using red rice. Phenolic compounds were identified by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) and caffeic acid content was measured by high-performance liquid chromatography with diode-array detection (HPLC-DAD). Caffeic and syringic acids were produced by G. lipsiense. In the control medium (red rice), the following compounds were identified: p-coumaric acid, salicylic acid, ferulic acid and vanillin. High concentrations of caffeic acid (0.977 µg g-1) were measured in 49 days. Antimicrobial activity was investigated against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus using a minimum inhibitory concentration (MIC) technique. Ganoderma lipsiense extract was only effective against P. aeruginosa. These data have proved to be satisfactory in the study of biosynthesis of caffeic acid and antibacterial compounds by G. lipsiense in solid-state fermentation with red rice.


Assuntos
Antibacterianos , Ácidos Cafeicos , Ganoderma/crescimento & desenvolvimento , Oryza/química , Fenóis/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/crescimento & desenvolvimento , Ácidos Cafeicos/metabolismo , Ácidos Cafeicos/farmacologia , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray
14.
J Glob Antimicrob Resist ; 16: 83-86, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30248412

RESUMO

OBJECTIVES: This study reports the draft genome sequence of Pseudoalteromonas piscicida strain 36Y_RITHPW, a marine Gammaproteobacteria that synthesises bioactive compounds with antagonistic activity against Vibrio parahaemolyticus, a multidrug-resistant strain that is the causative agent of acute hepatopancreatic necrosis disease (AHPND), reported in shrimp farm outbreaks from Asia to Mexico with mortality rates of 80-100%. METHODS: The genome of P. piscicida 36Y_RITHPW was sequenced with an Ion Torrent™ Personal Genome Machine™ (PGM) platform. A total of 606805 reads were constructed for a 308.48Mbp and 33.5×coverage. A high-quality draft assembly and ordering of contigs was obtained with Mauve. The annotation was obtained with RAST and antiSMASH. RESULTS: The genome size consists of 5.15Mbp, with a total of 4548 genes, 4217 protein-coding sequences and a GC content of 43.3%. Several resistance genes as well as other genes involved in the production of bacteriocins and ribosomally synthesised antibacterial peptides are also present. CONCLUSIONS: Mining of this draft genome provides valuable information to explain the antagonistic capacity of P. piscicida 36Y_RITHPW, a useful strain as a potential probiotic in shrimp aquaculture against pathogenic V. parahaemolyticus.


Assuntos
Genoma Bacteriano , Pseudoalteromonas/genética , Salinidade , Água do Mar/microbiologia , Animais , Antibiose , Aquicultura , México , Penaeidae/microbiologia , Probióticos , Pseudoalteromonas/fisiologia , Vibrio parahaemolyticus/fisiologia , Sequenciamento Completo do Genoma
15.
Molecules ; 23(1)2018 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-29351265

RESUMO

This study focused on the development of gelatin-based films with incorporation of microcrystalline cellulose as reinforcement material. Clove (Syzygium aromaticum), nutmeg (Myristica fragrans), and black pepper (Piper nigrum) oleoresins containing antimicrobial compounds of natural origin were incorporated into the films. The mechanical, thermal, optical, and structural properties, as well as color, seal strength and permeability to water vapor, light, and oil of the films were determined. Adding oleoresins to the gelatin matrix increased the elongation of the material and significantly diminished its permeability to water vapor and oil. Evaluation of the potential use of films containing different oleoresins as bread packaging material was influenced by the film properties. The biocomposite film containing oleoresin from black pepper was the most effective packaging material for maintaining bread's quality characteristics.


Assuntos
Anti-Infecciosos/química , Pão , Embalagem de Alimentos , Qualidade dos Alimentos , Gelatina/química , Anti-Infecciosos/farmacologia , Pão/microbiologia , Microbiologia de Alimentos , Gelatina/farmacologia , Fenômenos Mecânicos , Testes de Sensibilidade Microbiana , Permeabilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vapor , Termogravimetria , Difração de Raios X
16.
Food Res Int ; 102: 575-587, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29195988

RESUMO

Food safety and microbiological quality are major priorities in the food industry. In recent years, there has been an increasing interest in the use of natural antimicrobials in food products. An ongoing challenge with natural antimicrobials is their degradation during food storage and/or processing, which reduces their antimicrobial activity. This creates the necessity for treatments that maintain their stability and/or activity when applied to food. Microencapsulation of natural antimicrobial compounds is a promising alternative once this technique consists of producing microparticles, which protect the encapsulated active substances. In other words, the material to be protected is embedded inside another material or system known as wall material. There are few reports in the literature about microencapsulation of antimicrobial compounds. These published articles report evidence of increased antimicrobial stability and activity when the antimicrobials are microencapsulated when compared to unprotected ones during storage. This review focuses mainly on natural sources of antimicrobial compounds and the methodological approach for encapsulating these natural compounds. Current data on the microencapsulation of antimicrobial compounds and their incorporation into food suggests that 1) encapsulation increases compound stability during storage and 2) encapsulation of antimicrobial compounds reduces their interaction with food components, preventing their inactivation.


Assuntos
Anti-Infecciosos/administração & dosagem , Microbiologia de Alimentos/métodos , Inocuidade dos Alimentos/métodos , Cápsulas , Portadores de Fármacos , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Armazenamento de Alimentos/métodos , Microscopia Eletrônica de Varredura
17.
FEMS Microbiol Lett ; 364(12)2017 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-28637209

RESUMO

Novel compounds and innovative methods are required considering that antibiotic resistance has reached a crisis point. In the study, two cell-bound antimicrobial compounds produced by Lactococcus lactis ID1.5 were isolated and partially characterized. Following purification by cationic exchange and a solid-phase C18 column, antimicrobial activity was recovered after three runs of RPC using 60% (v/v) and 100% (v/v) of 2-propanol for elution, suggesting that more than one antimicrobial compound were produced by L. lactis ID1.5, which were in this study called compounds AI and AII. The mass spectrum of AI and AII showed major intensity ions at m/z 1070.05 and 955.9 Da, respectively. The compound AI showed a spectrum of antimicrobial activity mainly against L. lactis species, while the organisms most sensitive to compound AII were Bacillus subtilis, Listeria innocua, Streptococcus pneumoniae and Pseudomonas aeruginosa. The antimicrobial activity of both compounds was suppressed by treatment with Tween 80. Nevertheless, both compounds showed high stability to heat and proteases treatments. The isolated compounds, AI and AII, showed distinct properties from other antimicrobial substances already reported as produced by L. lactis, and have a significant inhibitory effect against two clinically important respiratory pathogens.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Lactococcus lactis/química , Antibacterianos/química , Bacillus subtilis/efeitos dos fármacos , Bacteriocinas/química , Bacteriocinas/metabolismo , Microbiologia de Alimentos , Lactobacillaceae/efeitos dos fármacos , Lactococcus lactis/isolamento & purificação , Lactococcus lactis/metabolismo , Listeria/efeitos dos fármacos , Polissorbatos , Pseudomonas aeruginosa/efeitos dos fármacos , Streptococcus pneumoniae/efeitos dos fármacos
18.
Nat Prod Res ; 29(22): 2133-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25533144

RESUMO

The antimicrobial activities as well as the nature of the inhibitory compounds obtained from Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium animalis strains were assayed on foodborne pathogenic - Staphyloccoccus aureus subsp. aureus (CCUG ATCC® 25926™) and Escherichia coli (ATCC® 25922™) - and spoilage microorganisms - Pseudomonas aeruginosa (ATCC® 27853™). Test producer strains showed inhibitory effect on all indicator microorganisms in diffusion of cell-free concentrated supernatant by agar in well methods (10.0-22.5 mm) in periods of 24, 48 and 72 h. Inhibitory compounds showed no sensitivity to the action of proteolytic enzyme trypsin and were completely inactivated by adjusting the pH of the cell-free 20 × concentrated supernatant to 7.0. The results demonstrated that antimicrobial substances do not have proteinaceous nature and are caused by the action of organic acids with decreasing medium pH.


Assuntos
Bifidobacterium/química , Microbiologia de Alimentos , Lacticaseibacillus casei/química , Probióticos , Meios de Cultivo Condicionados/química , Escherichia coli/efeitos dos fármacos , Contaminação de Alimentos , Staphylococcus aureus/efeitos dos fármacos
19.
Braz. j. microbiol ; Braz. j. microbiol;44(4): 1155-1161, Oct.-Dec. 2013. graf, tab
Artigo em Inglês | LILACS | ID: lil-705275

RESUMO

An increase in the consumption of fruit juices and minimally processed fruits salads has been observed in recent years all over the world. In this work, the microbiological quality of artisan fruit salads was analysed. Faecal coliforms, Salmonella spp, Shigella spp, Yersinia enterocolitica and Escherichia coli O157:H7 were not detected; nevertheless, eleven strains of Staphylococcus aureus were isolated. By multiplex PCR, all isolates showed positive results for S. aureus 16S rRNA gene and 63.6% of them were positive for sea gene. Furthermore, PCR sea positive strains were able to produce the corresponding enterotoxin. Finally, the inactivation of these strains in fruit salads by nisin, lysozyme and EDTA, was studied. EDTA produced a total S. aureus growth inhibition after 60 h of incubation at a concentration of 250 mg/L. The presence of S. aureus might indicate inadequate hygiene conditions during salad elaboration; however, the enterotoxigenicity of the strains isolated in this study, highlights the risk of consumers' intoxication. EDTA could be used to inhibit the growth of S. aureus in artisan fruit salads and extend the shelf life of these products.


Assuntos
Enterotoxinas/genética , Frutas/microbiologia , Staphylococcus aureus/isolamento & purificação , Argentina , DNA Bacteriano/genética , DNA Ribossômico/genética , Reação em Cadeia da Polimerase Multiplex , /genética , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo
20.
Braz J Microbiol ; 44(4): 1155-61, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24688505

RESUMO

An increase in the consumption of fruit juices and minimally processed fruits salads has been observed in recent years all over the world. In this work, the microbiological quality of artisan fruit salads was analysed. Faecal coliforms, Salmonella spp, Shigella spp, Yersinia enterocolitica and Escherichia coli O157:H7 were not detected; nevertheless, eleven strains of Staphylococcus aureus were isolated. By multiplex PCR, all isolates showed positive results for S. aureus 16S rRNA gene and 63.6% of them were positive for sea gene. Furthermore, PCR sea positive strains were able to produce the corresponding enterotoxin. Finally, the inactivation of these strains in fruit salads by nisin, lysozyme and EDTA, was studied. EDTA produced a total S. aureus growth inhibition after 60 h of incubation at a concentration of 250 mg/L. The presence of S. aureus might indicate inadequate hygiene conditions during salad elaboration; however, the enterotoxigenicity of the strains isolated in this study, highlights the risk of consumers' intoxication. EDTA could be used to inhibit the growth of S. aureus in artisan fruit salads and extend the shelf life of these products.


Assuntos
Enterotoxinas/genética , Frutas/microbiologia , Staphylococcus aureus/isolamento & purificação , Argentina , DNA Bacteriano/genética , DNA Ribossômico/genética , Reação em Cadeia da Polimerase Multiplex , RNA Ribossômico 16S/genética , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo
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