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1.
Rev. chil. nutr ; 47(2): 281-285, abr. 2020. tab
Article in English | LILACS | ID: biblio-1115499

ABSTRACT

Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.


Los conservantes sintéticos están ampliamente presentes en los alimentos procesados, pero la mayoría tienen potencial carcinogénico, lo que requiere el desarrollo de nuevas alternativas naturales para el control microbiano, como los extractos de frutas. El objetivo del estudio fue evaluar la caracterización química, la actividad antioxidante y antimicrobiana de la pulpa de manzana de azúcar (Annona squamosa L.). Se evaluaron las características fisicoquímicas, y se evaluó su actividad antioxidante mediante el método DPPH y antimicrobiano por difusión en disco, concentración inhibitoria mínima y concentración bactericida mínima contra cepas de Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes y Staphylococcus aureus. El análisis fisicoquímico reveló que la pulpa de manzana de azúcar tiene 75.0% de humedad, 3.0% de cenizas, 4.0% de proteínas, 0.2% de lípidos, 3.3% de fibras y 14.5% de carbohidratos. La actividad antioxidante del extracto por el método DPPH fue del 20.6%. El extracto de pulpa de la manzana de azúcar tenía zona de inhibición para Staphylococcus aureus, efecto inhibidor satisfactorio contra Staphylococcus aureus, Escherichia coli, Listeria monocytogenes y Salmonella Typhimurium, pero no presenta efecto bactericida. La pulpa de manzana de azúcar presenta niveles adecuados de nutrientes y potencial para la aplicación de alimentos debido a su actividad microbiológica y propiedades antioxidantes.


Subject(s)
Plant Extracts/pharmacology , Annona/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Salmonella typhimurium/drug effects , Staphylococcus aureus/drug effects , Carbohydrates/analysis , Plant Extracts/chemistry , Proteins/analysis , Microbial Sensitivity Tests , Escherichia coli/drug effects , Lipids/analysis , Listeria monocytogenes/drug effects , Anti-Bacterial Agents/chemistry , Antioxidants/chemistry
2.
Bol. latinoam. Caribe plantas med. aromát ; 18(4): 411-424, jul. 2019. tab, ilus
Article in English | LILACS | ID: biblio-1008180

ABSTRACT

Thymol (2-isopropyl-5-methylphenol) is an aromatic monoterpene found in essential oils extracted from plants belonging to the Lamiaceae family, such as Thymus, Ocimum, Origanum, Satureja, Thymbra and Monarda genera. Growth and biofilm formation by Listeria monocytogenes CLIP 74902 were evaluate using three carbon sources in the presence of thymol. Specific growth rate (h-1) values at 37o with glucose, trehalose and cellobiose with the addition of thymol (µg/mL) 0 (control) and 750, were respectively: 0.22, 0.07; 0.14, 0.04; 0.11, 0.04. Lag periods obtained under the same conditions were (h): 8.19, 13.2; 22.5, 27.5; 23.1, 28.1. A marked antibiofilm activity was observed against the exposure with 750 µg/mL of thymol, showing a high percentage of inhibition: glucose (99 %), trehalose (97 %) and cellobiose (98%), compared to the control. The results suggest that thymol could be used to inhibit the growth and production of biofilms by L. monocytogenes in the food industry.


Timol (2-isopropil-5-metilfenol) es un monoterpeno aromático presente en los aceites esenciales extraídos de plantas pertenecientes a la familia Lamiaceae, como los géneros Thymus, Ocimum, Origanum, Satureja, Thymbra y Monarda. El crecimiento y formación de biopelícula por Listeria monocytogenes CLIP 74902 fueron evaluados utilizando tres fuentes de carbono en presencia de timol. La velocidad específica de crecimiento (h-1) a 37o con glucosa, trehalosa y celobiosa con la adición de timol (µg/mL) 0 (control) y 750, fueron respectivamente: 0.22, 0.07; 0.14, 0.04, 0.11, 0,04. Los períodos lag obtenidos en las mismas condiciones fueron (h): 8.19, 13.2; 22.5, 27.5; 23.1, 28.1. Una marcada actividad antibiofilm fue obtenida con 750 µg/mL de timol, mostrando un alto porcentaje de inhibición con glucosa (99%), trehalosa (97%) y celobiosa (98%), respecto al control. Los resultados sugieren que timol podría ser usado para inhibir el crecimiento y producción de biopelículas por L. monocytogenes en la industria alimentaria.


Subject(s)
Thymol/pharmacology , Biofilms/drug effects , Listeria monocytogenes/drug effects , Terpenes/pharmacology , Kinetics , Biofilms/growth & development , Environment , Fermentation , Food Microbiology , Listeria monocytogenes/growth & development
3.
Braz. j. microbiol ; 49(1): 169-176, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889211

ABSTRACT

ABSTRACT Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum) were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine) and/or a histone deacetylase inhibitor (suberohydroxamic acid). Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66 ± 5.98% and 15.38 ± 1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%), when compared to the control extract (39.62 ± 3.76%). Similarly, inhibition of acetylcholinesterase activity increased from 20.91 ± 3.90% (control) to 92.20 ± 3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cholinesterase Inhibitors/pharmacology , Penicillium/chemistry , Talaromyces/chemistry , Acetylcholinesterase/chemistry , Acetylcholinesterase/metabolism , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/metabolism , Chromatin/metabolism , Listeria monocytogenes/drug effects , Listeria monocytogenes/enzymology , Listeria monocytogenes/growth & development , Penicillium/metabolism , Talaromyces/metabolism
4.
Braz. j. microbiol ; 49(supl.1): 113-118, 2018. tab, graf
Article in English | LILACS | ID: biblio-974319

ABSTRACT

Abstract Poultry meat is a food product that usually carries high rates of microbial contamination, including foodborne pathogens. The poultry industry has established different systems to minimize these hazards. In recent years, extensive literature has demonstrated the antimicrobial activity of different contact surfaces made of copper to effectively reduce microbial loads. The aim of the present study was to evaluate the antibacterial effect of copper surfaces on the transmission of two foodborne pathogens - Salmonella enterica and Listeria monocytogenes - and a poultry native microbiota bacterial species - Enterobacter cloacae. We also evaluated the impact of the poultry meat matrix on the antimicrobial activity of a copper surface. Our results indicated that copper surfaces reduced the bacterial load quickly (<than 4 min) when the microorganisms were exposed to polished copper surfaces. Even when bacteria were inoculated on copper surfaces soiled with the organic matrix (washing water from poultry carcasses) and survival rates were significantly higher, an antimicrobial effect was still observed. Survival rates of two microorganisms simultaneously exposed to copper did not show significant differences. We found an antimicrobial effect over pathogenic and non-pathogenic microorganisms. Results suggest a potential role for copper surfaces in the control of microbiological hazards in the poultry industry.


Subject(s)
Animals , Poultry/microbiology , Copper/pharmacology , Meat/microbiology , Anti-Bacterial Agents/pharmacology , Cadaver , Food Contamination/analysis , Salmonella enterica/drug effects , Microbiota/drug effects , Listeria monocytogenes/drug effects
5.
Braz. j. microbiol ; 48(4): 724-729, Oct.-Dec. 2017. tab
Article in English | LILACS | ID: biblio-889162

ABSTRACT

ABSTRACT The effectiveness of bacteriophage P100, nisin and sodium lactate, individually and in combination, in inhibiting Listeria monocytogenes in ready-to-eat pork ham slices was assessed. The antimicrobials were applied to the surfaces of ready-to-eat pork ham slices, which were inoculated with a mixture of L. monocytogenes. Among the individual antimicrobial treatments, bacteriophage P100 was the most effective, decreasing L. monocytogenes to undetectable levels at zero and 72 h post-infection. Sodium lactate was the least effective treatment. Treatment with nisin at zero h significantly reduced initial cell density (p < 0.05). However, this pattern was not observed at 72 h of storage. A significant difference (p < 0.05) existed between the results of separate bacteriophage and nisin treatments after refrigerated storage, but not immediately upon inoculation of the bacteria. The results showed that the use of bacteriophage P100 is the method of choice for the control of bacteria.


Subject(s)
Animals , Bacteriophages/physiology , Fast Foods/microbiology , Food Preservation/methods , Food Preservatives/pharmacology , Listeria monocytogenes/drug effects , Listeria monocytogenes/virology , Meat Products/microbiology , Nisin/pharmacology , Sodium Lactate/pharmacology , Food Preservation/instrumentation , Listeria monocytogenes/growth & development , Swine
6.
Braz. j. microbiol ; 47(3): 757-763, July-Sept. 2016. tab, graf
Article in English | LILACS | ID: lil-788979

ABSTRACT

ABSTRACT The inhibition of Listeria monocytogenes ATCC 7644 on fresh-cut tomato was investigated using nisin alone, and in combinations with organic salts. Nisin at a concentration of 5000 UI/mL was introduced alone or in combination with an organic salt (sodium citrate or sodium acetate each at 3 and 5 g/100 mL each) on fresh-cut tomato previously inoculated with 108 CFU/mL of L. monocytogenes ATCC 7644. Chlorine at 200 ppm was used as a control. The inoculated samples were incubated at different temperatures (4, 10 and 25 °C) and examined at 0, 24, 48 and 72 h. The effects of the antimicrobial treatments on quality parameters of tomato (pH, soluble solids, titratable acidity and vitamin C) were also evaluated, and colour parameters were observed at the lowest storage temperature for 10 days. Both nisin and the organic salts inhibited growth of L. monocytogenes, but the combinations of two compounds were more effective. The nisin-sodium citrate (5%) combination was significantly (p ≤ 0.05) effective, while chlorine was least effective against L. monocytogenes. The quality parameters were substantially retained, especially at 4 °C, suggesting good shelf stability at a low temperature. These results substantiate the use of the cheap and eco-friendly approach to reducing this pathogen of health concern in common fresh produce.


Subject(s)
Salts/pharmacology , Lycopersicon esculentum/microbiology , Listeria monocytogenes/drug effects , Nisin/pharmacology , Colony Count, Microbial , Microbial Viability/drug effects , Food Microbiology , Food Preservation/methods , Food Preservatives , Listeria monocytogenes/isolation & purification , Anti-Bacterial Agents/pharmacology
7.
Braz. j. microbiol ; 47(2): 438-443, Apr.-June 2016. tab
Article in English | LILACS | ID: lil-780817

ABSTRACT

Abstract Although the consumption of fresh and minimally processed vegetables is considered healthy, outbreaks related to the contamination of these products are frequently reported. Among the food-borne pathogens that contaminate vegetables is Listeria monocytogenes, a ubiquitous organism that exhibits the ability to survive and multiply at refrigerated temperatures. This study aimed to evaluate the occurrence of L. monocytogenes in vegetables as well as the antimicrobial resistance of isolates. The results showed that 3.03% of samples were contaminated with L. monocytogenes, comprising 2.22% of raw vegetables and 5.56% of ready-to-eat vegetables. Multiplex PCR confirmed the virulence potential of the isolates. Antimicrobial resistance profiling showed that 50% of the isolates were susceptible to the antibiotics used. The resistance of one isolate to penicillin G, a commonly employed therapeutic agent, and the presence of serotype 4b, a serotype commonly associated with food-borne outbreaks, could be potential health hazards for consumers.


Subject(s)
Vegetables/microbiology , Drug Resistance, Bacterial , Listeria monocytogenes/drug effects , Food Contamination/analysis , Listeria monocytogenes/isolation & purification , Anti-Bacterial Agents/pharmacology
8.
Braz. j. biol ; 75(4): 923-931, Nov. 2015. tab, graf
Article in English | LILACS | ID: lil-768199

ABSTRACT

Abstract Lactic acid bacteria (LAB) have an important role in a great variety of fermented foods. In addition to their contribution to sensory characteristics, they enhance food preservation and can be used as probiotics. In this study, the antimicrobial and antioxidant activities of culture supernatants and cell free extracts of 16 LAB isolated from meat and dairy products were investigated. The bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to Enterococcus faecium species. Antimicrobial activity against the indicator microorganism (Listeria monocytogenes) was observed at 11 culture supernatants and 4 cell free extracts. The sensibility of culture supernatant was evaluated by proteinase K and trypsin and it was observed that activity of antimicrobial substance was completely lost after the treatment. All of the isolates showed antioxidant activity as determined by the Thiobarbituric Acid Reactive Substances (TBARS) method with both types of extracts. When the antioxidant capacity was investigated using ABTS•+ method (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH method (2,2-diphenyl-1-picrylhydrazyl) it was observed that only culture supernatants showed antioxidant capacity. These bacteria could particularly help to reduce or inhibit pathogenic microorganisms as well as oxidative spoilage in foods and feed.


Resumo As bactérias ácido láticas (BAL) têm um papel importante em uma grande variedade de alimentos fermentados. Em adição à sua contribuição para as características sensoriais, estes microorganismos melhoram a conservação de alimentos e podem ser utilizados como probióticos. Neste estudo, as atividades antimicrobiana e antioxidante do sobrenadante e dos extratos livres de células de 16 isolados de LAB de carne e produtos lácteos foram investigadas. Os isolados foram identificados pelo sequenciamento da região 16S do rRNA. Após a comparação das sequências obtidas com aquelas disponíveis na base de dados GenBank, observou-e que todos os isolados foram pertencentes à espécie Enterococcus faecium. A atividade antimicrobiana contra o microrganismo indicador (Listeria monocytogenes) foi observada no sobrenadante das culturas em 11 isolados, e nos extratos livres de células por 4 isolados. A sensibilidade da cultura sobrenadante foi avaliada pela proteinase K e tripsina e observou-se que a atividade da substância antimicrobiana foi completamente perdida após o tratamento com as enzimas proteolíticas. Todos os isolados apresentaram atividade antioxidante, como determinado pelo método do ácido tiobarbitúrico de substâncias reativas (TBARS) com ambos os tipos de extratos. Quando a capacidade antioxidante foi investigada usando o método do ABTS (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) e o método de DPPH (2,2-diphenyl-1-picrylhydrazyl) observou-se que apenas os sobrenadantes das culturas demonstraram capacidade antioxidante. Estas bactérias poderiam particularmente ajudar a reduzir ou inibir microorganismos patogênicos, bem como a deterioração oxidativa em alimentos e rações.


Subject(s)
Anti-Infective Agents/pharmacology , Antioxidants/analysis , Dairy Products/microbiology , Enterococcus/chemistry , Listeria monocytogenes/drug effects , Meat/microbiology , Phylogeny , Sequence Analysis, DNA , Thiobarbituric Acid Reactive Substances/chemistry
9.
Braz. j. microbiol ; 46(1): 201-206, 05/2015. tab, graf
Article in English | LILACS | ID: lil-748231

ABSTRACT

Listeria monocytogenes is a pathogen frequently found in dairy products. Its control in fresh cheeses is difficult, due to the psychrotrophic properties and salt tolerance. Bacteriocinogenic lactic acid bacteria (LAB) with proven in vitro antilisterial activity can be an innovative technological approach but their application needs to be evaluated by means of in situ tests. In this study, a novel bacteriocinogenic Lactococcus lactis strain (Lc. lactis DF4Mi), isolated from raw goat milk, was tested for control of growth of L. monocytogenes in artificially contaminated fresh Minas type goat cheese during storage under refrigeration. A bacteriostatic effect was achieved, and counts after 10 days were 3 log lower than in control cheeses with no added LAB. However, this effect did not differ significantly from that obtained with a non-bacteriocinogenic Lc. lactis strain. Addition of nisin (12.5 mg/kg) caused a rapid decrease in the number of viable L. monocytogenes in the cheeses, suggesting that further studies with the purified bacteriocin DF4Mi may open new possibilities for this strain as biopreservative in dairy products.


Subject(s)
Animals , Antibiosis , Bacteriocins/metabolism , Cheese/microbiology , Goats , Lactococcus lactis/isolation & purification , Listeria monocytogenes/drug effects , Milk/microbiology , Bacterial Load , Food Preservation/methods , Food Safety/methods , Lactococcus lactis/metabolism
10.
Braz. j. microbiol ; 46(1): 231-235, 05/2015. graf
Article in English | LILACS | ID: lil-748241

ABSTRACT

Listeria monocytogenes is a foodborne pathogen able to adhere and to form biofilms in several materials commonly present in food processing plants. The aim of this study was to evaluate the resistance of Listeria monocytogenes attached to abiotic surface, after treatment with sanitizers, by culture method, microscopy and Quantitative Real Time Polymerase Chain Reaction (qPCR). Biofilms of L. monocytogenes were obtained in stainless steel coupons immersed in Brain Heart Infusion Broth, under agitation at 37 °C for 24 h. The methods selected for this study were based on plate count, microscopic count with the aid of viability dyes (CTC-DAPI), and qPCR. Results of culture method showed that peroxyacetic acid was efficient to kill sessile L. monocytogenes populations, while sodium hypochlorite was only partially effective to kill attached L. monocytogenes (p < 0.05). When, viability dyes (CTC/DAPI) combined with fluorescence microscopy and qPCR were used and lower counts were found after treatments (p < 0.05). Selective quantification of viable cells of L. monocytogenes by qPCR using EMA revelead that the pre-treatment with EMA was not appropriate since it also inhibited amplification of DNA from live cells by ca. 2 log. Thus, the use of CTC counts was the best method to count viable cells in biofilms.


Subject(s)
Bacterial Load/methods , Biofilms/drug effects , Disinfectants/pharmacology , Environmental Microbiology , Listeria monocytogenes/drug effects , Listeria monocytogenes/physiology , Microbial Viability/drug effects , Biofilms/growth & development , Colony Count, Microbial , Listeria monocytogenes/isolation & purification , Microscopy , Real-Time Polymerase Chain Reaction , Temperature , Time
11.
Indian J Biochem Biophys ; 2015 Feb; 52 (1): 45-59
Article in English | IMSEAR | ID: sea-157955

ABSTRACT

Listeriosis, in particular that caused by Listeria monocytogenes, is a major foodborne pathogen, and its control is becoming difficult because of widespread emergence of drug resistance strains. Chorismate synthase (CS), an essential enzyme of shikimate pathway present only in bacteria, fungi, plant and some apicomplexan parasites, is a validated potential antimicrobial drug target. Antimicrobial development through the elucidation of essential structural features of the CS of L. monocytogenes (LmCS), identification and prioritization of potential lead compounds targeted against LmCS were done. Structure-based virtual screening and docking studies were performed using Autodock tools to retrieve potential candidates with high affinity binding against LmCS model from several ligand repositories. The potency of binding was also checked with other structurally similar CS from Streptococcus pneumoniae (SpCS) and Mycobacterium tuberculosis (MtCS). The sequence and structural studies revealed LmCS was similar to be other CS structures (1Q1L, 1QXO, 1R52, 1R53, 1SQ1, 1UM0, 1UMF, 1ZTB, 2011, 2012, 4ECD and 2G85) with each monomer presenting β-α-β sandwich topology with a central helical core. Molecular docking studies and ADME/Tox results revealed that ZINC03803450 and ZINC20149031 were most potent molecules binding into the active site of LmCS. Other two ligands ZINC13387711 and ZINC16052528 showed a strong binding affinity score against all three structures (LmCS, SpCS and MtCS) and bind to LmCS with the predicted inhibition constant (Ki) values of 22.94 nM and 35.84 nM, respectively. A reported benzofuran-3[2H]-one analog CHEMBL135212 with good ADME/Tox properties and experimental IC50 (nM) value of 7000 nM with SpCS could also be considered as a potential inhibitor of LmCS, as compared to previously reported 41 benzofuran-3[2H]-one analogs against SpCS. This information will assist in discovering those compounds that may act as potent CS inhibitors. Further experimental studies and evaluation of structure-activity relationship could help in the development of potential inhibitors against listeriosis, as well as antibacterial chemotherapy.


Subject(s)
Anti-Bacterial Agents , Ligands/analysis , Ligands/therapeutic use , Listeria monocytogenes/drug effects , Molecular Docking Simulation/methods , Phosphorus-Oxygen Lyases/analysis , Phosphorus-Oxygen Lyases/therapeutic use
12.
Braz. j. microbiol ; 45(1): 89-96, 2014. ilus, tab
Article in English | LILACS | ID: lil-709483

ABSTRACT

This study was conducted to evaluate the antibacterial effect of Carum copticum essential oil (Ajowan EO) against Listeria monocytogenes in fish model system. Ajowan EO chemical composition was determined by gas chromatography/mass spectral analysis and the highest concentration of Carum copticum essential oil without any significant changes on sensory properties of kutum fish (Rutilus frisii kutum) was assigned. Then the inhibitory effect of Ajowan EO at different concentrations in presence of salt and smoke component was tested on L. monocytogenes growth in fish peptone broth (FPB), kutum broth and cold smoked kutum broth at 4 ºC for 12 days. Ajowan EO completely decreased the number of L. monocytogenes in FPB after 12 days of storage, however, antimicrobial effect of EO significantly reduced in kutum and cold smoked kutum broth. Addition of 4% NaCl and smoke component improved the anti-listerial activity of Ajowan EO in all fish model broths.


Subject(s)
Animals , Anti-Bacterial Agents/pharmacology , Carum/chemistry , Fish Diseases/drug therapy , Fish Diseases/microbiology , Listeria monocytogenes/drug effects , Listeriosis/veterinary , Oils, Volatile/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Colony Count, Microbial , Culture Media/chemistry , Cyprinidae/microbiology , Gas Chromatography-Mass Spectrometry , Listeriosis/drug therapy , Listeriosis/microbiology , Microbial Viability/drug effects , Oils, Volatile/chemistry , Oils, Volatile/isolation & purification , Sodium Chloride/metabolism , Temperature
13.
Braz. j. microbiol ; 44(4): 1181-1188, Oct.-Dec. 2013. ilus, tab
Article in English | LILACS | ID: lil-705259

ABSTRACT

This study was developed in order to evaluate two alternatives for the control of Listeria monocytogenes in raw bovine meat pieces, both based on the use of Thymus vulgaris and Rosmarinus officinalis essential oils (EOs). The antilisterial activity of different concentrations of the EOs was tested in vitro using agar dilution and disk volatilization techniques. In addition, L. monocytogenes was inoculated in meat pieces, which were submerged in edible gelatin coatings containing 2% (v/v) EOs or submitted to the vapor of EOs (0.74 μL.cm-3). L. monocytogenes was quantified after one, 48 and 96 hours of storage (7 °C). In the in vitro tests, the EO of T. vulgaris presented higher activity. The two options used (edible gelatin coating and vapor activity), in spite of exercising effects with differentiated behaviors, presented antibacterial activity against L. monocytogenes inoculated in raw bovine meat (p < 0.05). Greatest antibacterial activity were obtained in the experiment that used edible coatings containing EOs, at 48 hours of storage reductions in bacterial counts between 1.09 and 1.25 Log CFU.g-1 were obtained. In the vapor effect experiment, the EO of T. vulgaris caused the highest reduction in the population of bacteria inoculated in raw bovine meat (p < 0.05), 0.40 Log CFU.g-1 at 96 hours of storage. This study supplied important information regarding new and promising natural alternatives, based on the concept of active packaging, for the control of L. monocytogenes in the meat industry.


Subject(s)
Animals , Cattle , Anti-Bacterial Agents/pharmacology , Food Preservatives/pharmacology , Listeria monocytogenes/drug effects , Meat/microbiology , Oils, Volatile/pharmacology , Thymus Plant/chemistry , Anti-Bacterial Agents/isolation & purification , Bacterial Load , Food Preservatives/isolation & purification , Listeria monocytogenes/growth & development , Microbial Sensitivity Tests , Oils, Volatile/isolation & purification , Rosmarinus/chemistry , Temperature
14.
Braz. j. microbiol ; 44(4): 1163-1167, Oct.-Dec. 2013. graf, tab
Article in English | LILACS | ID: lil-705277

ABSTRACT

The antimicrobial activity of the bacteriocin-like substance (BLS) P34 against Listeria monocytogenes was investigated in chicken sausage. The BLS was applied to chicken sausages (256 AU g-1) previously inoculated with a suspension of 10² cfu g-1 of L. monocytogenes. BLS P34 inhibited the indicator microorganism in situ in all incubation times for up to 10 days at 5 °C. The effectiveness of BLS P34 was increased when it was added in combination with nisin. The bacteriocin was also tested in natural eatable natural bovine wrapping (salty semi-dried tripe) against the same indicator microorganism, also showing inhibitory capability in vitro. BLS P34 showed potential to control L. monocytogenes in refrigerated meat products.


Subject(s)
Animals , Cattle , Anti-Bacterial Agents/pharmacology , Food Microbiology , Listeria monocytogenes/drug effects , Peptides/pharmacology , Chickens , Food Preservatives/pharmacology , Listeria monocytogenes/growth & development , Nisin/pharmacology , Temperature , Time Factors
15.
Braz. j. microbiol ; 44(4): 1189-1194, Oct.-Dec. 2013. ilus, tab
Article in English | LILACS | ID: lil-705283

ABSTRACT

The aim of this study was to assess the activity of essential oil extracted from the leaves of C. blanchetianus Baill, popularly known as "marmeleiro", in inhibiting the growth and survival of pathogenic microorganisms in food by determining their survival in vitro and by observing the behaviour of Listeria monocytogenes inoculated into a food model (meat cubes) that was stored at refrigeration temperature (7 ± 1 ºC) for 4 days. The results indicated a bactericidal effect against Aeromonas hydrophila and Listeria monocytogenes and bacteriostatic action against Salmonella Enteritidis. A bacteriostatic effect on meat contaminated with L. monocytogenes was found for all concentrations of essential oils tested. These results showed that essential oil from the leaves of C. blanchetianus Baill represents an alternative source of potentially natural antimicrobial agents that may be used as a food preservative.


Subject(s)
Aeromonas hydrophila/drug effects , Anti-Bacterial Agents/pharmacology , Croton Oil/pharmacology , Croton/chemistry , Listeria monocytogenes/drug effects , Oils, Volatile/pharmacology , Salmonella enteritidis/drug effects , Anti-Bacterial Agents/isolation & purification , Bacterial Load , Croton Oil/isolation & purification , Food Preservatives/isolation & purification , Food Preservatives/pharmacology , Microbial Viability/drug effects , Oils, Volatile/isolation & purification , Plant Leaves/chemistry , Temperature
16.
Arch. latinoam. nutr ; 63(3): 247-253, sep. 2013. ilus, tab
Article in Spanish | LILACS | ID: lil-749967

ABSTRACT

En la literatura científica mundial, existen muchos estudios que demuestran la capacidad antimicrobiana de diferentes hierbas, incluyendo el té verde. No obstante, muchos resultados son divergentes o no comparables. También, existen en el mercado muchas formulaciones de té verde, de las cuales hay poca información respecto a su actividad. En el presente trabajo se determinó el potencial efecto antimicrobiano contra cepas de Escherichia coli, Salmonella enterica, Listeria monocytogenes, Staphylococcus aureus, Candida albicans y Aspergillus niger de 50 muestras diferentes de té verde seco y en infusión al 10%, distribuidas de manera comercial en Costa Rica. Se contrastó su actividad con la del té verde (Camellia sinensis) de origen chino. Se evaluaron diferentes solventes para preparar extractos ricos en polifenoles a partir del té verde. Los fenoles totales se determinaron mediante el método espectrofotométrico de Folin-Ciocalteu usando el ácido gálico como material de referencia. La evaluación de la capacidad antimicrobiana del extracto y las infusiones de té verde se llevó a cabo mediante el método de microplatos descrito por Breukink (2006). El etanol fue el solvente que mostró mayor eficiencia. No hubo efecto antimicrobiano de las diferentes muestras contra los microorganismos evaluados, excepto con Listeria monocytogenes, dondese evidenció un efecto inhibitorio en las concentraciones de 10,5 y 1,05 mg/mL de los extractos en el 70% de marcas analizadas y en el control. Ninguna de las infusiones evaluadas, incluyendo la del té control mostró efecto inhibitorio contra esta bacteria.


Many studies can be found in scientific literature demonstrating the antimicrobial capacity of different herbs, including green tea. Nevertheless, many results are divergent or cannot be compared. Several green tea formulations may be found in market, but there is scarce or non-information about its activity. In this work, the potential antimicrobial effect of 50 samples of dry green tea and in 10% infusion against Escherichia coli, Salmonella enterica, Listeria monocytogenes, Staphylococcus aureus, Candida albicans and Aspergillus niger distributed in the metropolitan area of Costa Rica, was determined. This activity was compared with the effect produced by Chinese origin green tea (Camellia sinensis). Different solvents were evaluated for preparing polyphenol enriched extracts from green tea samples. Total phenols were determined using the Folin-Ciocalteu spectrophotometric methodology, using galic acid as reference. Antimicrobial activity of green tea extracts and infusions was evaluated using the microplate methodology described by Breuking (2006). Ethanol was the most efficient solvent used for the polyphenol extractions. There was no antimicrobial effect of the different green tea extracts and infusions against the microorganisms evaluated, except for Listeria monocytogenes, where the extracts of 70% of samples analyzed and the control showed an inhibitory effect in the 10,5 mg/mL and 1,05 mg/L concentrations. None of the infusions tested, including the control, showed any effect against this bacteria.


Subject(s)
Anti-Bacterial Agents/pharmacology , Camellia sinensis/chemistry , Microbial Sensitivity Tests , Tea/chemistry , Anti-Bacterial Agents/isolation & purification , Aspergillus niger/drug effects , Costa Rica , Candida albicans/drug effects , Escherichia coli/drug effects , Listeria monocytogenes/drug effects , Salmonella enterica/drug effects , Staphylococcus aureus/drug effects
17.
Rev. argent. microbiol ; 45(2): 93-8, jun. 2013.
Article in Spanish | LILACS, BINACIS | ID: biblio-1171779

ABSTRACT

Yerba mate (Ilex paraguariensis St. Hil.) has been studied for its important biological activities mainly attributed to phenolic compounds. This study evaluated the antimicrobial activity of methanolic and ethanolic extracts of yerba mate against food pathogens, such as Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli through minimum inhibitory (MIC) and bactericidal (MBC) concentrations, in addition to the determination of chemical composition by gas chromatography with mass spectrometry (GC-MS) and phenolic content. The most effective extract had its activity evaluated under different pH conditions by growth curve analysis. All microorganisms except E. coli were inhibited. The ethanolic extract showed the lowest MIC/MBC (0.78/0.78 mg/ml), the highest phenolic content (193.9 g.GAE/kg) and the presence of chlorogenic acid derivatives, especially 3-O-caffeoylquinic and caffeic acid. This extract was able to inhibit microbial growth at pH 7 and 8.


Subject(s)
Escherichia coli/drug effects , Plant Extracts/pharmacology , Ilex paraguariensis , Listeria monocytogenes/drug effects , Salmonella enteritidis/drug effects , Staphylococcus aureus/drug effects , Food Microbiology
18.
Arch. latinoam. nutr ; 63(2): 173-179, June 2013. ilus, tab
Article in Spanish | LILACS | ID: lil-740238

ABSTRACT

Listeria monocytogenes ha sido considerado como un patógeno emergente causante de enfermedades alimentarias. En la búsqueda de una vía alterna biocontroladora de su propagación, se propone al xilitol como posible agente bacteriostático y/o bactericida. El xilitol es un poliol derivado de la hidrogenación del monosacárido xilosa de relevancia en la industria farmacéutica por su efecto anticariogénico. Para comprobar el efecto del xilitol como posible agente bacteriostático y/o bactericida sobre Listeria monocytogenes, se determinó la concentración mínima inhibitoria (CMI), el tiempo mínimo de inhibición (TMI) y la concentración bactericida mínima (CBM) de soluciones de xilitol en cultivos de Listeria monocytogenes ATCC 7635. Se aplicó el método de difusión en agar, utilizando soluciones de xilitol en concentraciones de 0 a 10%, respectivamente, para la CMI. El TMI se determinó por curvas de crecimiento en caldo Soya tripticasa con soluciones de 1, 2, 3, 5, 8, 9, 10 y 20% de xilitol, respectivamente, con un inoculo inicial de 108 UFC de Listeria monocytogenes por mL en cada solución. Se observó que la CMI fue con la solución del 1% de xilitol; el TMI fue de 10 horas con las concentraciones de 1 a 10% y de 7 horas al aplicar 20% xilitol. Se comprobó que efectivamente el xilitol tiene poder bacteriostático sobre Listeria monocytogenes (p<0.001), más sin embargo, no se obtuvo efecto bactericida en los ensayos realizados.


Listeria monocytogenes has been considered as an emerging pathogen causing foodborne illness. In the search for an alternate route biocontrol propagation, xylitol has been proposed as a possible bacteriostatic and / or bactericide. Xylitol is a polyol derived from the hydrogenation of xylose monosaccharide of importance in the pharmaceutical industry for its anti-cariogenic effect. To check the possible effect of xylitol as bacteriostatic and /or bactericidal against Listeria monocytogenes, it was determined the minimum inhibitory concentration (MIC), the time minimum inhibition (TMI) and minimum bactericidal concentration (MBC) of xylitol solutions on Listeria monocytogenes ATCC 7635. The agar diffusion method was applied, using xylitol solutions at concentrations of 0-10%, respectively, for the MIC. The TMI was determined by growth curves in trypticase soy broth with solutions 1, 2, 3, 5, 8, 9, 10 and 20% of xylitol, respectively, with an initial inoculum of 108 CFU per ml of Listeria monocytogenes in each solution. MIC observed was the solution 1% of xylitol; the TMI was 10 hours to concentrations of 1 to 10% and 7 hours to apply 20% xylitol. It was found that xylitol has bacteriostatic power on Listeria monocytogenes (p <0.001), but not bactericide effect.


Subject(s)
Anti-Bacterial Agents/pharmacology , Listeria monocytogenes/drug effects , Xylitol/pharmacology , Colony Count, Microbial , Microbial Sensitivity Tests , Xylitol/chemistry
19.
Braz. j. microbiol ; 44(2): 357-365, 2013. graf, tab
Article in English | LILACS | ID: lil-688567

ABSTRACT

This research evaluated the antimicrobial effect of the clove (Syzygium aromaticum) and lemongrass (Cymbopogon citratus (DC.) Stapf.) essential oils (EOs) against Listeria monocytogenes ATCC 19117 growth added to bovine ground meat stored under refrigeration (5 ± 2 °C) for three days. The EOs, extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), were tested in vitro using an agar well diffusion methodology for determination of Minimum Inhibitory Concentration (MIC). The MIC concentrations for both essential oils on culture tested of L. monocytogenes were 1.56%. The EOs concentrations applied in contaminated ground beef were 1.56, 3.125 and 6.25% (w/v) based on MIC levels and possible activity reductions by food constituents. The bacteria populations were significantly reduced (p < 0.05) after one day of storage in ground meat samples treated with clove and lemongrass EOs at concentrations of 1.56%. There were no significant counts of L. monocytogenes in samples at the other concentrations of the two oils applied after the second day of storage. The sensory acceptability evaluation of the bovine ground meat samples treated with EOs showed that the addition at concentrations higher than 1.56% promote undesirable alterations of taste, odor and characteristic color. The application of EOs at low concentrations in food products can be used in combination with other preservation methods, such as refrigeration, to control pathogens and spoilage bacteria during shelf-life; which goes according to current market trends, where consumers are requesting natural products.


Subject(s)
Animals , Cattle , Anti-Bacterial Agents/pharmacology , Cymbopogon/chemistry , Eugenia/chemistry , Listeria monocytogenes/drug effects , Meat/microbiology , Oils, Volatile/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Food Preservatives/chemistry , Food Preservatives/isolation & purification , Food Preservatives/pharmacology , Gas Chromatography-Mass Spectrometry , Listeria monocytogenes/growth & development , Microbial Sensitivity Tests , Oils, Volatile/chemistry , Oils, Volatile/isolation & purification , Refrigeration , Temperature
20.
Journal of Medicinal Plants. 2013; 12 (48): 104-116
in Persian | IMEMR | ID: emr-148730

ABSTRACT

Natural biopreservative are as alternative approach for controlling growth of food borne microorganisms such as Listeria monocytogenes. Essential oils [EOs] possess antibacterial properties. Mentha is one of the most common aromatic plants that widely used as medicinal and biopreservative in food. Nisin a well known antibacterial peptide to effectively antagonize a broad spectrum of bacteria, and is widely used as preservative in food. The aim of this work was to investigate the antimicrobial efficacies of nisin and Mentha spicata essential oil in combination against Listeria monocytogenes. The effects of different temperatures [4, 9 and 14°C], pH [5, 6 and 7] and NaCl concentrations [0, 1, 2 and 4%] were determinate. Description study. Essential oil content of M. Spicata had 18 components. The dominant active components were carvone [78.76%], limonene [11.50%] and menthol [1%]. Minimum inhibitory concentrations for the essential oil and nisin were 160 micro ml and 320IU/ml, respectively. A synergy of low pH values, high temperatures and high NaCl concentrations was observed. Our results found that the combination effects of M. Spicata and nisin in all experimental concentrations significantly reduced the numbers of L. monocytogenes


Subject(s)
Nisin , Listeria monocytogenes/drug effects , Anti-Infective Agents , Oils, Volatile , Drug Combinations
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