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1.
Br J Nutr ; 130(7): 1137-1143, 2023 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36690581

RESUMO

To assess the glycaemic response after ingestion of two specialised oral and enteral nutrition formulas for glycaemic control. The participants were sixteen healthy volunteers, aged 21-49 years, with normal glucose tolerance. The volunteers attended the tests fasting for 10 h, for 5 weeks, and consumed the reference food - glucose solution - for 3 weeks, and the two formulas DiamaxO and DiamaxIG in the following weeks, in amounts equivalent to 25 g of available carbohydrates. During the period of 120 min, seven blood samples were taken through capillary blood sampling to determine the glycaemic response. The glycaemic index (GI) was calculated according to the trapezoidal rule, ignoring areas below the fasting line. The glycaemic load (GL) was determined by the formula GL = ((GI(glucose = reference) × 'g' of available carbohydrate per serving]/100. The formulas showed low GI and GL. GI = 37·8 and GL = 6·6 for DiamaxO and GI = 21·5 and GL = 3·5 for DiamaxIG. The peak of the glycaemic response occurred 30 min after ingestion, with a marked difference in blood glucose between the Diamax products in relation to glucose. Differences were also significant at times 15, 45, 60 and 90 min in relation to glucose (ANOVA with post hoc Bonferroni, P < 0·005), but not between the two products. However, the AUC and the GI of DiamaxIG are significantly smaller than that of the DiamaxO second t test (P = 0·0059). The glycaemic response to the products is quite reduced, presenting a curve with a little accentuated shape, without high peak, especially in the modified product.


Assuntos
Carboidratos da Dieta , Controle Glicêmico , Humanos , Glicemia , Índice Glicêmico , Glucose
2.
J Appl Microbiol ; 132(2): 1185-1196, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34365710

RESUMO

AIMS: To gather data on agricultural practices in organic farms in Sao Paulo, Brazil, and evaluate their relationship with the microbiological characteristics of samples collected along the production chain. METHODS AND RESULTS: Practices data were based on field observations and interviews with farmers in 10 selected organic lettuce producing farms. Counts of Enterobacteriaceae and surveys for Salmonella were performed in samples of lettuce (before and after washing), fertilizers, irrigation and washing water, all collected in the same farm. Water samples were also tested for total coliforms and generic Escherichia coli. Isolated Enterobacteriaceae were identified by MALDI-TOF MS. Contamination of lettuce was influenced by some agricultural practices: chicken manure-based fertilization resulted in higher Enterobacteriaceae counts in lettuce when compared to other types of manure, whereas pre-washed lettuces presented lower microbial counts than non-pre-washed samples. Salmonella was detected in one lettuce sample by qPCR. Escherichia coli was detected in all irrigation water samples. All sample types contained Enterobacteriaceae species commonly reported as opportunistic human pathogens. CONCLUSIONS: The data highlight the need for improvement in the good agricultural practices in the studied farms. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides information on agricultural practices and microbiological characteristics of organic lettuce, contributing to the development of more accurate risk assessments.


Assuntos
Agricultura , Agricultura Orgânica , Brasil , Fazendas , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Humanos , Lactuca , Salmonella/genética
3.
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
4.
Matern Child Nutr ; 16 Suppl 3: e13005, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33347721

RESUMO

Centralizing chemical composition data for biodiverse foods is an important strategy in promoting their consumption. To support this strategy, a dataset of foods based on Brazilian biodiversity was created. The set was based on data for foods produced or commercialized in Brazil; these data were previously compiled for the Brazilian Food Composition Table (TBCA), according to international guidelines. Inclusion criteria were based on the following indicators: (i) foods with description below species level; (ii) wild foods; and (iii) underutilized foods. The dataset contains 1,305 food entries, and the majority correspond to raw plant foods. Nutrient content in foods identified below species level exhibited a wide range of values. Underutilized foods presented similar or higher selected nutrient contents than commonly consumed foods. For instance, depending on the cultivar of sweet potato (Ipomoea batatas), vitamin A content ranged from a negligible amount to high content (0.33- to 3,637-µg retinol equivalents per 100-g edible portion on a fresh weight basis [EP]). Camu-camu (Myrciaria dubia), a fruit from Amazon, was identified as the richest source of vitamin C (2,300 mg of ascorbic acid per 100-g EP), corresponding to 48-fold the content of orange. The dataset provides evidence to promote nutrient-rich foods that may be integrated into more effective programmes and policies on nutrition and food security in Brazil. It can be accessed online, free of charge on the TBCA platform.


Assuntos
Biodiversidade , Frutas , Vitamina A , Brasil , Humanos , Estado Nutricional , Valor Nutritivo
5.
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
6.
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
7.
Food Microbiol ; 34(2): 376-81, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23541205

RESUMO

Lactobacillus (Lb.) plantarum ST71KS was isolated from homemade goat feta cheese and identified using biochemical and molecular biology techniques. As shown by Tricine-SDS-PAGE, this lactic acid bacterium produces a bacteriocin (ST71KS) with an estimated molecular weight of 5.0 kDa. Bacteriocin ST71KS was not affected by the presence of α-amylase, catalase and remained stable in a wide range of pH and after treatment with Triton X-100, Triton X-114, Tween 20, Tween 80, NaCl, SDS, urea and EDTA. This bacteriocin also remained active after being heated at 100 °C for 2 h and even after 20 min at 121 °C; however, it was inactivated by proteolitic enzymes. Production of bacteriocin ST71KS reached 6400 AU/mL during stationary growth phase of Lb. plantarum cultivated in MRS at 30 °C and 37 °C. Bacteriocin ST71KS displayed a bactericidal effect against Listeria monocytogenes strains 603 and 607 and did not adsorb to the producer cells. Lb. plantarum ST71KS harbors two bacteriocin genes with homology to plantaricin S and pediocin PA-1. These characteristics indicate that bacteriocin ST71KS is a class IIa bacteriocin. The peptide presented no toxic effect when tested in vitro with kidney Vero cells, indicating safe technological application to control L. monocytogenes in foods.


Assuntos
Bacteriocinas/química , Queijo/microbiologia , Lactobacillus plantarum/metabolismo , Animais , Bacteriocinas/genética , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Linhagem Celular , Chlorocebus aethiops , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus plantarum/genética , Lactobacillus plantarum/isolamento & purificação , Células Vero
8.
Foodborne Pathog Dis ; 10(3): 197-205, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23489044

RESUMO

The globalization of food supply impacts patterns of foodborne disease outbreaks worldwide, and consumers are having increased concern about microbiological food safety. In this sense, the assessment of epidemiological data of foodborne diseases in different countries has not only local impact, but it can also be of general interest, especially in the case of major global producers and exporters of several agricultural food products, such as Brazil. In this review, the most common agents of foodborne illnesses registered in Brazil will be presented, compiled mainly from official databases made available to the public. In addition, some representative examples of studies on foodborne bacterial pathogens commonly found in Brazilian foods are provided.


Assuntos
Surtos de Doenças , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Bactérias/isolamento & purificação , Brasil/epidemiologia , Qualidade de Produtos para o Consumidor , Humanos
9.
Anaerobe ; 20: 42-9, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23357316

RESUMO

The aims of this study were to characterize inhibitory activity spectra, some probiotic properties and safety of Lactobacillus curvatus A61 for its future application in production of fermented foods. The studied strain was isolated from traditional homemade cheese manufactured in Azerbaijan. The cell-free supernatant of culture of Lb. curvatus A61 inhibited the growth of tested LAB, as well as of Listeria monocytogenes and Bacillus cereus strains. The strain presented antifungal activity and inhibited the growth of Cladosporium and Fusarium ssp. during co-cultivation on agar media. PCR amplification with specific primers revealed the presence of curvacin A encoding gene in Lb. curvatus A61. Bacteriocin produced by the studied strain was heat stable and active in a broad pH range, and in the presence of Triton X-20, Triton X-80, Triton X-100, ß-mercaptoethanol, Na-EDTA, SDS and NaCl. The mode of action of bacteriocin against selected indicator strains was found to be bacteriostatic. Lb. curvatus A61 was resistant to physiological concentrations of bile salts and showed high auto-aggregation ability, as well as co-aggregation ability with pathogenic L. monocytogenes strains. It was sensitive to chloramphenicol, penicillin, tetracycline, ciprofloxacin and vancomycin, but resistant to ampicillin and gentamicin.


Assuntos
Antifúngicos/metabolismo , Bacteriocinas/biossíntese , Queijo/microbiologia , Lactobacillus/isolamento & purificação , Listeria monocytogenes/efeitos dos fármacos , Probióticos , Antibacterianos/biossíntese , Azerbaijão , Bacillus cereus/efeitos dos fármacos , Bacteriocinas/genética , Cladosporium/efeitos dos fármacos , Fermentação , Fusarium/efeitos dos fármacos , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Testes de Sensibilidade Microbiana
10.
Microorganisms ; 11(3)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36985176

RESUMO

Candida albicans is an important vaginosis causative agent, affecting several women worldwide each year. This study reports on two strains of lactic acid bacteria (Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch) expressing bacteriocin-like inhibitor substances (BLIS) active against C. albicans 1281. Both strains were γ-hemolytic and not affected by numerous antibiotics, contraceptives, and commercial drugs, suggesting safety for human use. The recorded antimicrobial activity of semi-purified BLIS was 25,600 AU/mL for E. mundtii CRL35 and 800 AU/mL for E. faecium ST88Ch. Treatment of BLIS with 1 mg/mL proteinase K resulted in complete loss of antimicrobial activity against Listeria monocytogenes ATCC 15313 and partial loss of activity against C. albicans 1281. The killing effect of the semi-purified BLIS on cell suspensions of C. albicans 1281 after 9 h of contact was dose-dependent: for E. mundtii CRL35, 400 AU/mL to 25,600 AU/mL caused 63.61% to 79.35% lysis, while for E. faecium ST88Ch, 200 AU/mL to 800 AU/mL caused 29.32% to 31.25% cell lysis. The effects of temperature, pH, and presence of the contraceptive Nordette-28 on the adsorption levels of the BLIS to C. albicans 1281 were also evaluated. Nordette-28 (10% or 20%) promoted increased adsorption of both studied BLIS to the cells of C. albicans 1281 at pH 5.0, while a minor effect was observed at pH 3.0. Different levels of aggregation between C. albicans 1281 and E. mundtii CRL35 or E. faecium ST88Ch were recorded, and optimal adsorption levels were recorded at 37 °C. Appropriate BLIS-producing strains can effectively contribute to the equilibrium of vaginal microbial status quo and reduce negative consequences from the development of C. albicans infections.

11.
Food Microbiol ; 32(1): 38-47, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22850372

RESUMO

Several strains of Enterococcus spp. are capable of producing bacteriocins with antimicrobial activity against important bacterial pathogens in dairy products. In this study, the bacteriocins produced by two Enterococcus strains (Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch), isolated from cheeses, were characterized and tested for their capability to control growth of Listeria monocytogenes 426 in experimentally contaminated fresh Minas cheese during refrigerated storage. Both strains were active against a variety of pathogenic and non-pathogenic microorganisms and bacteriocin absorption to various L. monocytogenes, Enterococcus faecalis ATCC 19443 and Lactobacillus sakei ATCC 15521 varied according to the strain and the testing conditions (pH, temperature, presence of salts and surfactants). Growth of L. monocytogenes 426 was inhibited in cheeses containing E. mundtii CRL35 up to 12 days at 8 °C, evidencing a bacteriostatic effect. E. faecium ST88Ch was less effective, as the bacteriostatic affect occurred only after 6 days at 8 °C. In cheeses containing nisin (12.5 mg/kg), less than one log reduction was observed. This research underlines the potential application of E. mundtii CRL35 in the control of L. monocytogenes in Minas cheese.


Assuntos
Bacteriocinas/metabolismo , Queijo/microbiologia , Enterococcus faecium/metabolismo , Enterococcus/metabolismo , Conservação de Alimentos/métodos , Listeria monocytogenes/crescimento & desenvolvimento , Bacteriocinas/farmacologia , Enterococcus/química , Enterococcus faecium/química , Microbiologia de Alimentos , Listeria monocytogenes/efeitos dos fármacos
12.
Front Microbiol ; 12: 735931, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34594318

RESUMO

The emergence of multidrug-resistant bacteria stimulates the search for new substitutes to traditional antimicrobial agents, especially molecules with antivirulence properties, such as those that interfere with quorum sensing (QS). This study aimed to evaluate the potential of phenolic compounds for QS inhibition in a QS biosensor strain (Chromobacterium violaceum) and three foodborne bacterial species (Aeromonas hydrophila, Salmonella enterica serovar Montevideo, and Serratia marcescens). Initially, an in silico molecular docking study was performed to select the compounds with the greatest potential for QS inhibition, using structural variants of the CviR QS regulator of C. violaceum as target. Curcumin, capsaicin, resveratrol, gallic acid, and phloridizin presented good affinity to at least four CviR structural variants. These phenolic compounds were tested for antimicrobial activity, inhibition of biofilm formation, and anti-QS activity. The antimicrobial activity when combined with kanamycin was also assessed. Curcumin, capsaicin, and resveratrol inhibited up to 50% of violacein production by C. violaceum. Biofilm formation was inhibited by resveratrol up to 80% in A. hydrophila, by capsaicin and curcumin up to 40% in S. Montevideo and by resveratrol and capsaicin up to 60% in S. marcescens. Curcumin completely inhibited swarming motility in S. marcescens. Additionally, curcumin and resveratrol increased the sensitivity of the tested bacteria to kanamycin. These results indicate that curcumin and resveratrol at concentrations as low as 6µM are potential quorum sensing inhibitors besides having antimicrobial properties at higher concentrations, encouraging applications in the food and pharmaceutical industries.

13.
Front Microbiol ; 12: 666922, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33959118

RESUMO

Artisanal cheeses made with raw milk are highly appreciated products in Brazil. Most of these cheeses are produced in small facilities across different production regions in the country, some of which have been granted a protected designation of origin and are award winners. The most prominent state that manufactures these products is Minas Gerais (MG), but production is also gaining strength in other Brazilian states. The major challenge faced by artisanal cheese production is related to microbial risks associated with foodborne pathogens when the quality of the raw milk is unsatisfactory. Regulations created for the dairy industry are constantly been revised and adapted, considering the small-scale production of Brazilian artisanal cheeses, in order to guarantee safety at all steps of cheese production and commercialization. This text presents a summary of the huge diversity of artisanal cheeses produced in the country, grouped by geographical regions, and reviews the current challenges faced by producers and government considering the safety of these cheeses.

14.
Food Microbiol ; 27(7): 869-79, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20688228

RESUMO

The bacteriocin-producing strain Enterococcus faecium ST5Ha was isolated from smoked salmon and identified by biomolecular techniques. Ent. faecium ST5Ha produces a pediocin-like bacteriocin with activity against several lactic acid bacteria, Listeria spp. and some other human and food pathogens, and remarkably against HSV-1 virus. Bacteriocin ST5Ha was produced at high levels in MRS broth at 30 degrees C and 37 degrees C, reaching a maximum production of 1.0 x 10(9) AU/ml, checked against Listeria ivanovii ATCC19119 as target strain and surrogate of pathogenic strain Listeria monocytogenes. The molecular weight of bacteriocin ST5Ha was estimated to be 4.5 kDa according to tricine-SDS-PAGE data. Ent. faecium ST5Ha harbors a 1.044 kb chromosomal DNA fragment fitting in size to that of pediocin PA-1/AcH. In addition, the sequencing of bacteriocin ST5Ha gene indicated 99% of DNA homology to pediocin PA-1/AcH. The combined application of low levels (below MIC) of ciprofloxacin and bacteriocin ST5Ha resulted in a synergetic effect in the inhibition of target strain L. ivanovii ATCC19119. Bacteriocin ST5Ha displayed antiviral activity against HSV-1, an important human pathogen, with a selectivity index of 173. To the best of our knowledge, this is the first report on Ent. faecium as a potential producer of pediocin-like bacteriocin with antiviral activity.


Assuntos
Bacteriocinas/farmacologia , Enterococcus faecium/fisiologia , Herpesvirus Humano 1/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Salmão/microbiologia , Animais , Antibacterianos/farmacologia , Antibiose , Antivirais/farmacologia , Bacteriocinas/biossíntese , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Enterococcus faecium/metabolismo , Microbiologia de Alimentos , Herpesvirus Humano 1/crescimento & desenvolvimento , Humanos , Listeria/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Peso Molecular , Alimentos Marinhos/microbiologia
15.
Meat Sci ; 83(3): 523-7, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20416665

RESUMO

Linguiça is a highly popular and appreciated pork product in Brazil, frequently consumed undercooked. Aiming at collection of data for a future risk assessment, this study evaluated the prevalence and counts of Listeria monocytogenes in linguiça samples collected at retail level in Sao Paulo, SP, Brazil. ISO methods were used for detection and enumeration of the pathogen (11290-1 and 11290-2, respectively). Isolates were submitted to Simplex-PCR for hlyA gene and those with biochemical features of L. monocytogenes and hlyA positive were serotyped using a Multiplex PCR. Ninety percent of the samples were positive for Listeria spp., and L. monocytogenes was detected in 42% of the samples, with counts below 10(2)CFU/g in all samples. A prevalence of uncommon serotypes 4a and 4c was observed.

16.
Microorganisms ; 7(3)2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893864

RESUMO

Microbiological testing is an important quality management tool in the food industry. In this study, the hygiene status of beef carcasses sampled in eight Brazilian slaughterhouses was assessed by enumeration of different hygiene indicator microorganisms, and a model to establish potential associations among these counts was proposed. The carcasses (n = 464) were surface sampled at four slaughtering steps (step 1: Hide after bleeding; step 2: Carcass after hide removal; step 3: Carcass after evisceration; step 4: Carcass after end washing) and subjected to a counting of mesophilic aerobes (MA), Enterobacteriaceae (EB), total coliforms (TC), and Escherichia coli (EC) using Petrifilm™ plates. Among the sampled beef carcasses (step 4), 32 (6.9%) and 71 (15.3%) presented counts above the microbiological criteria established by (EC) No. 1441/2007 for MA and EB, respectively. Thus, indicating that improvements in slaughter hygiene and a review of process controls are demanded in some of the studied slaughterhouses. The log count differences of EC, TC, and EB from MA were considered as response variables as a function of the slaughtering steps. Differential log counts changed consistently with the steps. The measurements, including the patterns in their inherently random variability, were fairly predictable from steps 1 and 4. The results indicated that differential log counts for TC and EC are not relevant, as their concentrations and random pattern can be inferred from counts of MA and EB. The proposed model can be used as a valuable tool for the design and adoption of feasible quality control programs in beef industries. The adoption of such a tool should have a positive contribution on consumers' health and enhance product quality.

17.
Food Chem ; 193: 128-33, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26433298

RESUMO

Dietary fiber (DF) contributes to the energy value of foods and including it in the calculation of total food energy has been recommended for food composition databases. The present study aimed to investigate the impact of including energy provided by the DF fermentation in the calculation of food energy. Total energy values of 1753 foods from the Brazilian Food Composition Database were calculated with or without the inclusion of DF energy. The energy values were compared, through the use of percentage difference (D%), in individual foods and in daily menus. Appreciable energy D% (⩾10) was observed in 321 foods, mainly in the group of vegetables, legumes and fruits. However, in the Brazilian typical menus containing foods from all groups, only D%<3 was observed. In mixed diets, the DF energy may cause slight variations in total energy; on the other hand, there is appreciable energy D% for certain foods, when individually considered.


Assuntos
Fibras na Dieta/análise , Análise de Alimentos/métodos , Brasil , Bases de Dados Factuais , Metabolismo Energético
18.
Appl Biochem Biotechnol ; 175(6): 2806-22, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25637509

RESUMO

Lactic acid bacteria (LAB, n = 57) were previously obtained from raw goat milk, identified as Lactococcus spp. (n = 24) and Enterococcus spp. (n = 33), and characterized as bacteriocinogenic. Fingerprinting by pulsed field gel electrophoresis (PFGE) demonstrated high genetic diversity, and 30 strains were selected and exhibited strong antimicrobial activity against 46 target strains (LAB, spoilage, and foodborne pathogens). Six strains (Lactococcus lactis: GLc03 and GLc05; and Enterococcus durans: GEn09, GEn12, GEn14, and GEn17) were selected to characterize their bacteriocinogenic features, using Listeria monocytogenes ATCC 7644 as the target. The six strains produced bacteriocins at higher titer when incubated in MRS at 37 °C up to 12 h, when compared to growth at 25 and 30 °C. The produced bacteriocins kept their antimicrobial activity after exposure to 100 °C for 2 h and 121 °C for 20 min; the antimicrobial activity was also observed after treatment at pH 2.0 to 10.0, except for GLc03. L. monocytogenes populations were reduced approximately two logs after treatment with cell-free supernatants from the selected strains. These data show that goat milk can contain a diverse microbiota able to inhibit L. monocytogenes, a common pathogen found in dairy products, and can be potentially employed in biopreservation of food produced under different processing conditions.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Variação Genética , Lactobacillaceae/genética , Leite/microbiologia , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Bactérias/efeitos dos fármacos , Bacteriocinas/química , Bacteriocinas/metabolismo , Cabras , Concentração de Íons de Hidrogênio , Lactobacillaceae/classificação , Lactobacillaceae/isolamento & purificação , Lactobacillaceae/metabolismo , Dados de Sequência Molecular , Filogenia
19.
Braz J Microbiol ; 46(1): 237-49, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26221113

RESUMO

This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens . Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.


Assuntos
Queijo/microbiologia , Enterococcus faecium/isolamento & purificação , Enterococcus faecium/fisiologia , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Aderência Bacteriana , Brasil , Fenômenos Químicos , Ácidos Cólicos/metabolismo , Ácidos Cólicos/toxicidade , Clostridium perfringens/química , Clostridium perfringens/fisiologia , Enterococcus faecium/química , Escherichia coli/química , Escherichia coli/fisiologia , Trato Gastrointestinal/química , Interações Hidrofóbicas e Hidrofílicas , Inativação Metabólica , Viabilidade Microbiana/efeitos dos fármacos , Reação em Cadeia da Polimerase , Fatores de Virulência/análise , Fatores de Virulência/genética
20.
Rev Inst Med Trop Sao Paulo ; 56(6): 461-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25351537

RESUMO

Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.


Assuntos
Antibacterianos/farmacologia , Microbiologia de Alimentos/estatística & dados numéricos , Salmonella/efeitos dos fármacos , Salmonella/patogenicidade , Fatores de Virulência/genética , Brasil , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Testes de Sensibilidade Microbiana , Prevalência , Salmonella/isolamento & purificação , Infecções por Salmonella/microbiologia
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