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Calendula officinalis and propolis extracts have a wide range of biological activities, including antimicrobial action against a variety of pathogenic microorganisms. The aim of this study was to produce a mouthwash containing extracts of propolis and/or C. officinalis, with antimicrobial and antioxidant activity against pathogenic microorganisms implicated in periodontitis. The antimicrobial activity of extracts was evaluated based on the well diffusion assay. Total phenols, flavonoids and radical scavenging activity were evaluated by spectrophotometric method. The extract that showed greater antioxidant and antimicrobial potential against bacterial strains isolated from patients with periodontal disease were used for the composition of five mouthwash formulations. Thus, Staphylococcus aureus, Streptococcus salivarius and Streptococcus pneumoniae were used as antimicrobial activity indicator microorganisms. Staphylococcus aureus ATCC 25923, Streptococcus mutans ATCC 25175 and Enterococcus faecalis ATCC 29212 were used as control group. Five mouthwash formulations were developed, differing in the addition or not of raw propolis extract (20%), chlorhexidine digluconate or sodium fluoride (0.05%). The results indicate that propolis extract was more efficient than the calendula extract with antimicrobial action superior compared to azithromycin against S. pneumoniae, isolated from patients with stage III/IV periodontitis. The propolis extract had a higher flavonoid content (0.288 ± 0.038 mg EQ/g) than marigold extract. The F5 formulation containing chlorhexidine was more efficient in inhibiting Gram-positive pathogens, followed by formulations no. 2 and no. 4 which contained propolis extract. In this perspective, the propolis extract presented not only antimicrobial activity, but also antioxidant activity. Thus, the use of propolis in pharmaceutical formulas, such as the one presented here, could be especially useful in oral hygiene, contributing to the prevention of periodontitis.

As infecções do trato urinário (ITU´s) são causadas mais comumente por bactérias da família Enterobacteriaceae, particularmente a Escherichia coli. As mulheres são mais frequentemente acometidas por ITU´s. Nesta breve revisão, o objetivo foi realizar uma abordagem sobre ITU´s, o uso de antibióticos e a resistência bacteriana a antimicrobianos. A resistência microbiana a antibióticos é uma preocupação constante, principalmente para os profissionais da área da saúde. Nesta revisão, verificou-se que a resistência bacteriana ainda continuará sendo um grande problema de saúde pública. Novos antimicrobianos precisam ser desenvolvidos para ampliar as possibilidades de cura de infecções recorrentes. No entanto, a resistência bacteriana é o grande desafio a ser vencido.

Phenotyping based on conventional microbiological, physiological, and molecular analysis by using ARDRA technique was developed with the aim to assess the pathogenic microbial load associated with different stages of the periodontal disease. In addition, in the face of the global issue of antimicrobial resistance, the isolated bacterial strains were evaluated for their antibiotic susceptibility profile. The pathogenic bacterial community was predominantly of Gram-negative strains (66.66%). The most common species were Citrobacter freundii, Bacillus sp., Raoutella sp., Klebsiella ozaenae and Pseudomonas sp. However, except for the healthy control group, Staphylococcus spp. was isolated from all stages of periodontitis. Multidrug resistance to beta-lactam antibiotics was observed for Streptococcus pneumoniae, Raoutella sp. and Enterococcus avium. Here, we verify a statistically significant relationship between periodontitis stages and the diversity of the bacterial community. Patients with periodontitis showed a more diverse and numerous bacterial community compared to healthy patients. In this sense, we reinforce that biofilms that harbour multidrug-resistant bacteria are a major concern in relation to restoring patient health. Thus, prophylactic measures for maintaining oral health are still the best option for reduce the risk of disease. GRAPHIC ABSTRACT: [Image: see text]

Aims: To evaluate in vitro antimicrobial potential of 35% reconstituted juice (RJCr) against bacterial pathogen related to urinary tract infections (UTIs). Place and Duration of Study: Food and Biotechnology Laboratory, Brazil. Study Design: Cranberry juice for in vitro evaluation by agar well diffusion assay and direct in vitro assay. Methodology: Cranberry fruits were used to produce RJCr pH 3. Five bacterial pathogens were tested: Escherichia coli ATCC 35218, Klebsiella pneumoniae ATCC 700603, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853 and Proteus mirabilis, an isolate of clinical origin. Two methods were used to assess antimicrobial activity. In the agar well diffusion (AWD) assay, each pathogen was inoculated on agar plates and the juice was added in wells drilled on this agar by incubation at 35°C/24hours. Then, the diameter of the inhibition zone was measured (mm). Based on dilutions methods, a direct in vitro assay (DA) was also performed. In test tubes 4.5 ml of RJCr was added an inoculum of each pathogen for a final concentration of >106 and

Aims: To propose a primary nutritional recommendation for patients in the early stage of SLE to contribute to a better quality of life for those affected by the disease. Methodology: This is a theoretical study, with no direct approach or intervention to any patient. The research was carried out using a conceptual approach based on a narrative and explanatory literature review. The main key descriptors of health were: Lupus and skin lesions; butterfly wing or arthritis, nutrition and lupus. After that, a diet (with a menu) for primary nutritional guidance to patients with early symptoms was followed. Results: The scientific literature evaluates that Systemic Lupus Erythematosus (SLE) is a chronic, autoimmune inflammatory disease, with no cure, which can have multiple causes (hormonal, infectious, genetic and environmental). The production of autoantibodies in tissues, generated from recognized apoptotic fragments, processed and associated with the Principal Human Histocompatibility Complex are also characteristic of SLE. In addition, SLE is mainly characterized by the involvement of the skin, joints, kidneys and serous membranes. The symptoms of SLE vary according to the stage of the disease, affecting different organs, tissues and, in more severe cases, the central and peripheral nervous system. The incidence of SLE is about ten times higher in females and affects more commonly Afro-American, Hispanic and Asian people. In addition, the individual's eating habits and nutritional status can influence the intensity and worsening of symptoms. Regarding nutritional guidance, it is of utmost importance to have anti-inflammatory and antioxidant substances in the diet, avoiding the exaggeration of bad fats, refined carbohydrates, and proteins. Conclusion: SLE patients should receive a multidisciplinary therapeutic approach, including follow-up by a nutritionist, who will prioritize the maintenance of the patient's adequate weight, avoiding overloading of his joints. This will contribute for a better quality of life for those affected.

The antimicrobial potential of cranberry hydro alcoholic extracts (CrE) was evaluated against Escherichia coli isolated from women with urinary tract infection (UTI). CrE was diluted based on the percentage of proanthocyanidins (PACs) in extract powder for final concentrations: 1.26%; 2.52%; 3.35%, 5.03% and 10.06%. CrE antimicrobial potential was evaluated by disk and well diffusion assays, and by in vitro direct action against E. coli. Antibacterial action was observed for all performed tests: minimal inhibitory concentration (MIC) was 1.26% PACs per disk diffusion assay and 2.52% of PACs by well diffusion assay. The in vitro antimicrobial direct action against E. coli resulted 3.8 Log10 cycles reduction for a concentration of 5.03% of PACs. One of the isolates showed multi resistance to antibiotics. But it was also inhibited more than any of the antibiotic tested in well diffusion assay. Only for concentrations 1.26%, 2.52% and 3.45% the inhibition of Escherichia coli by cranberry extract was dose-dependent, i.e directly proportional to the concentration of PACs. The results indicate a inhibitory action high potential of CrE. However, more in vitro and in vivo analysis can be performed to fix which the best concentration of CrE capable of causing a real beneficial effect on UTI´s.

A pork sausage was produced with low sodium content (1.64%) to which Lactobacillus sakei was added with the aim of developing a meat pork sausage for cooking and having technological, organoleptic, and hygienic advantages. The lactic acid bacteria (LAB) L. sakei, Lactococcus sp., and Pediococcus pentosaceus were submitted to extreme pH, temperature, and NaCl conditions. Lactobacillus sakei was used in pork sausage because of its resistance to different culture conditions and its antimicrobial potential. The food-borne pathogens Listeria monocytogenes Scott A, Enterococcus faecalis, and Staphylococcus aureus were used as indicator microorganisms to evaluate the antimicrobial activity of selected LAB strains. Salmonella enterica serotype Choleraesuis is a common pathogen of pigs. To the raw sausage product containing L. sakei and nonpathogenic endogenous microbiota, we added about >104 and 5 CFU/g of S. enterica serotype Choleraesuis to evaluate the inhibitory potential of L. sakei towards this pathogen. Salmonella Choleraesuis was inhibited in the presence of L. sakei over 7 days of storage of the meat product (about 3.0 log cycles reduction). Lactobacillus sakei significantly increased inhibition when compared with the nonfermented sausage. Thus, L. sakei BAS0117 played an important role as an additional hurdle in the fermented meat pork sausage during storage.

A new, simple, and low-cost method is proposed to determine ethanol content in beer samples. The method is economical and environmentally friendly because it uses low-cost materials based on natural indicators and generates only 200 μL of waste per test. The method is based in the reaction of ethanol with potassium dichromate in acid media generating Cr3+; 100 μL of K2Cr2O7 0.2 mol L−1 in sulfuric acid 20%, v/v was placed in wells of a 96-micro-well plate, then, 50 μL of samples or standards were placed in each well, after 1 h incubation at 60 °C, a digital image of the plate was obtained using a flatbed scanner, and RGB values were extracted automatically from all wells in less than 5 min using ImageJ’s plugin “ReadPlate.” The standard calibration plot was linear for an ethanol content ranging from 0.4 to 2%, with limits of detection and quantification of 0.09% and 0.27%, respectively. Ethanol content determined in beer samples with proposed method agree with those obtained with the microplate reader and with those claimed in labels. Thus, this method can be especially advantageous for countries were available resources for analytical equipment investments are scant.

The global trend is to minimize losses by using by-products from slaughterhouses as part of sustainable food production, both for human and animal consumption. Another growing trend is the development of pet feed with properties beneficial to the consumer's health. Another trend is the development of feeds with beneficial properties for the health of animals. Thus, the objective of this study was to use mechanically separated pork meat and by-products (trachea) to produce a pet snack containing the encapsulated probiotic yeast Saccharomyces boulardii. The experimental design followed in three main stages: 1) development of a pet pork snack (trachea snack); 2) microencapsulation of the probiotic and insertion in the pet snack; 3) Shelf life evaluation and palatability of the pet snack. S. boulardii was microencapsulated by extrusion technique and remained viable after 120 days of shelf life. The acceptability index of the probiotic pet snack was 77.8%. We concluded that S. boulardii provides beneficial probiotics characteristics to pet snack whose composition has high levels of protein (57.50%). Thus, the novel pet product has a good appeal to the functional products market.

The aim of this work was to isolate and investigate different yeast strains obtained in the Brazilian Midwest Region. The alcohol fermenting industrial yeast Saccharomyces cerevisiae CAT-1 and another 3 strains previously isolated from a sugar and alcohol mill were also investigated. In this sense, 45 strains were isolated from fruits and chicken litter. They were evaluated through biochemical and molecular analyzes. Then, it was proceded the enzymatic evaluation and the molecular identification of 13 potential strains, selected due to the fermentation capacity of the substrates glucose, fructose and sucrose. One isolate was distinguished by its short time of fermentation (Candida glabrata Recol 43) and another 3 by their high activity of pyruvate dehydrogenase (Candida glabrata Recol 41, Candida parapsilosis Recol 29 and Meyerozyma guilliermondii Recol 9). The complete characterization performed here helped to identify novel yeasts with potential for biotechnological applications in biofuel and food industries.

A pork sausage was produced with low sodium content (1.64%) to which

Several species of the genus Exophiala are found as opportunistic pathogens on humans, while others cause infections in cold-blooded waterborne vertebrates. Opportunism of these fungi thus is likely to be multifactorial. Ecological traits [thermotolerance and pH tolerance, laccase activity, assimilation of mineral oil, and decolorization of Remazol Brilliant Blue R (RBBR)] were studied in a set of 40 strains of mesophilic Exophiala species focused on the salmonis-clade mainly containing waterborne species. Thermophilic species and waterborne species outside the salmonis-clade were included for comparison. Strains were able to tolerate a wide range of pHs, although optimal growth was observed between pH 4.0 and 5.5. All strains tested were laccase positive. Strains were able to grow in the presence of the compounds (mineral oil and RBBR) with some differences in assimilation patterns between strains tested and also were capable of degrading the main chromophore of RBBR. The study revealed that distantly related mesophilic species behave similarly, and no particular trend in evolutionary adaptation was observed.

Resistance to antibiotics has being considered one of the greatest public health problems worldwide. The objective of this systematic review was to compile important bibliographical references that support the studies related to the biotechnological potential of antimicrobial peptides. Antimicrobial peptides are considered the major components of the innate immune system and work in defence against infections caused by different microorganisms. Many researchers argue that the studies associated with the discoveries of antimicrobial peptides that are more effective in the treatment of infections caused by microorganisms be also directed to the substances produced by insects. The major aspects associated to the technological potential of antimicrobial peptides are, general characteristics, classification, mode of action and prospects for applying, mainly in the pharmaceutical industry. It can be concluded that research for new substances with action against pathogenic microorganisms aim mainly to seek alternatives to the use of antibiotics. In addition, anticancer peptides are small cationic molecules with promising pharmacological use. However, the products for application in the protection of food, treatment of skin infections and its use in the cosmetics industry are those with the greatest potential.

50 rice samples (18 organic and 32 ordinary) from Brazil were analyzed with inductively coupled plasma mass spectrometry (ICP-MS) for 20 elements (As, B, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, K, La, Mg, Mn, Mo, P, Pb, Rb, Se and Zn) to identify significant differences between the two types (organic and ordinary) of rice. Concentrations of As, B, Ba, Co, Cr, Cu, Mn, P and Zn were found to be higher in ordinary versus organic rice, while K, Ca, Mo, Rb and Se concentrations were lower in ordinary versus organic samples. The remaining investigated elements (Cd, Ce, Fe, La, Mg and Pb) exhibited statistically equivalent concentration in the two types of rice. Principal Component Analysis (PCA), Soft Independent Modeling of Class Analogy (SIMCA), Hierarchical Cluster Analysis (HCA) and K-nearest neighbors (KNN) statistical techniques of the elemental fingerprints were readily able to discriminate organic from ordinary samples and can be used as alternative methods for adulteration evaluation.

Elemental determination was carried out on 36 grape juice samples (19 organic and 17 ordinary), with the goal of identifying significant differences between the two types of juice for classification purposes. Inductively coupled plasma-mass spectrometry was used for the determination of 24 elements, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, La, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Se, Sn, Ti, V, and Zn. Ba, Ce, La, Mg, P, Pb, Rb, Sn, and Ti concentrations were found to be higher in organic versus ordinary samples, while Na and Va concentrations were higher in ordinary versus organic samples. The remaining investigated elements exhibited statistically equivalent concentration levels in both types of samples. Principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA) statistical techniques of the elemental fingerprints were readily able to discriminate organic from ordinary samples and can be used as alternative methods for adulteration evaluation.

The present study assessed the diversity of black yeast-like fungi present on babassu coconut shells, a substrate rich in lipids and several volatile organic compounds (VOCs) including aromatic hydrocarbons. Using different isolation methods, one-hundred-six isolates were obtained and were identified by ITS sequencing as members of the genera Exophiala, Cladophialophora, Veronaea, and Rhinocladiella. Two novel species were discovered. Eight strains were selected for assessing their ability to grow on toluene and phenyl acetate as the sole carbon and energy source. All strains tested were able to assimilate phenyl acetate, while two out of eight were able to use toluene. VOCs profiling in babassu samples was also investigated by GC-ToF MS, revealing that a complex mixture of VOCs was emitted, which included alkylbenzenes such as toluene. Assimilation of alkylbenzenes by the black yeasts might therefore be the result of evolutionary adaptation to symbiotic interactions with higher plants. The potential relationship between lipid/aromatic hydrocarbon metabolism and pathogenicity is also discussed.

Rapid monitoring and hygiene conditions of handlers in a food industryAbstractMicroorganisms are present in water, air, soil, plants, animals and foods. Thus, any cool or processed foodproducts can be contaminated by various forms of microorganisms, especially when good hygiene practicesare not observed. This research evaluated the microbiota in the hands of employees after hand washing anduse of one of disinfectants: alcohol 70% and 0,5% biguanide. This assessment was base on the diagnosis ofsanitary and hygienic conditions in the establishment of standards and operating procedures of hygiene-SSOP. Were established twenty points samples for six consecutive months. Each sample was obtained directlyon the surface of the manipulators’ hands by using Petrifilm™ plates (cards) to Total Plate Count foraerobic mesophilic, and presence of Enterobacteriaceae. Thus, one hundred and six samples were collectedto determine the total amount of aerobic mesophilic (CFU/cm2) and 12 samples were used to assess thepresence of Enterobacteriaceae. The average aerobic mesophilic microorganisms after using alcohol 70%,and 0,5% biguanide was 5.08 and 5.87 CFU/cm2, respectively and showed a high variability in both groupswith standard deviations greater than the average coefficient of variation exceeding 100%. No differenceswere found in the average number of microorganisms after using any kind of disinfectants. We concludedthat Petrifilm™ is a quick way to achieve the microbiological monitoring of food handlers, but the use ofdisinfectants should be standardized. The absence of Enterobacteriaceae suggests that the disinfectants wereeffective in maintaining sanitary conditions suitable for those food handlers.

Essential oils of plants are considered sources of biological active substances. The family Asteraceae has been widely studied in relation to its chemical composition and biological activity. In the genus Baccharis the flavonoids and terpenoids are the most commonly studied compounds. B. dracunculifolia DC, is native to the Brazilian cerrado and considered the main botanical source of green propolis. The aims of this study were to evaluate the antibacterial activity of the essential oil from leaves and flowers of B. dracunculifolia and its active compound, the nerolidol. This compound was utilized pure or in combined form with EDTA or with lysozyme against Gram positive and negative pathogenic bacteria strains. The techniques of well diffusion agar and disc diffusion filter paper were utilized to test antibacterial activity of the following substances: essential oil of B. dracunculifolia (Ole30), pure nerolidol or combined with EDTA or lysozyme, and different antibiotics used as control: gentamicin, tetracycline, streptomycin, oxacillin, chloramphenicol, vancomicin, penicillin, amoxicillin, rifampin and erythromycin. The most inhibited bacteria by the Ole30 were: Proteus sp., Staphylococcus sp, Escherichia coli and Listeria monocytogenes. In well diffusion assay, both Ole30 and chloramphenicol inhibited Proteus sp., Staphylococcus sp. and L. monocytogenes but Salmonella enterica subsp. enterica Typhimurium and S. Panama were resistant to the Ole30. In both techniques Staphylococcus aureus ATCC 25923 was resistant to the Ole30. The nerolidol inhibited Staphylococcus sp. and L. monocytogenes, and combined with EDTA inhibited Proteus sp. and combined with lysozyme inhibited S. aureus ATCC 25923 and L. monocytogenes.

The combined action of ascorbic acid and two commercial enzymatic complexes containing amylase and xylanase/amylase was analyzed to determine their effects on dough rheology and bread quality. Seven bread formulations containing different concentrations of these improvers were used in the analysis. The rheological properties of each dough formulation were determined by moisture, gluten and farinograph tests. The breads were also characterized in general aspect - especially shelf-life - based on the presence of fungi. The dough rheology results showed that the formulation developed in the presence of 0.01% xylanase/amylase and 200 ppm of ascorbic acid was more efficient. Improved shelf-life was obtained from the formulations containing xylanase. The results showed that some technological characteristics of dough rheology and gluten index produced from the combination of these improvers can indicate in order to obtain specific features of the bread. Key words: Food biotechnology, xylanase, amylase, dough properties, bread improvers.

The prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae varies worldwide, however, the incidence of ESBL-producing environmental Salmonella isolates is increasing. Salmonella is still one of the most important pathogens that occur in the poultry supply chain. Therefore, this study analyzed the susceptibility of Salmonella isolates collected from a poultry supply chain to β-lactam antibiotics, and examined the phenotypes of the isolates based on enzyme-inducible AmpC β-lactamase analysis. All analysis of the putative positive isolates in the current study confirmed that 27.02% (77/285 analysis) of all ESBL tests realized with the isolates produced a profile of resistance consistent with β-lactamase production. All isolates of S. Minnesota serotype had ESBL phenotype. Aztreonam resistance was the least common amongst the Salmonella isolates, followed by ceftazidime. The presence of inducible chromosomal ESBL was detected in 14 different isolates of the 19 serotypes investigated. These results are very indicatives of the presence of ESBL genes in Salmonella isolates from a broiler supply chain, reaffirming the growing global problem of ESBL resistance.

O crescimento economico e a globalizacao tem influenciado a mudanca dos habitos dos brasileiros, inclusive os alimentares. A procura por refeicoes fora de casa cresce cada vez mais. Entre as opcoes para quem busca rapidez no atendimento, variedade no cardapio e baixo custo, estao os restaurantes do tipo self service. Mesmo adeptos desses servicos, os consumidores tambem buscam uma alimentacao saudavel. Nesta pesquisa foram avaliadas as condicoes higienico-sanitarias de saladas de vegetais servidas em tres restaurantes self service de uma cidade do interior de Santa Catarina. Porcoes de 200g de saladas de vegetais crus frescos e prontos para consumo foram obtidas durante 5 dias numa mesma semana em cada restaurante, totalizando 15 coletas. Em quatro, das cinco amostragens, 100% das amostras estavam improprias para consumo, ou seja, em desacordo com a legislacao vigente para contagem de coliformes totais e coliformes termotolerantes. Escherichia coli foi confirmada para um dos restaurantes, mas Salmonella sp. nao foi detectada em nenhuma das amostras. Para evitar o risco de DTA´s e considerando que a contaminacao pode ocorrer em todas as etapas de preparo de alimentos, e necessario que os restaurantes adotem medidas rigorosas de higiene, bem como boas praticas de processamento e disposicao do alimento ao consumidor. Palavras-chave: Restaurantes, Doencas transmitidas por alimentos. 10.5216/ref.v10i3.22023

17 Lactobacillus curvatus and one Lactobacillus brevis isolate were obtained from salami. The isolates were previously selected according to the desirable characteristics regarding technological criteria. Identification was based primarily on the biochemical carbohydrate assimilation profile, and later by amplified 16S rDNA restriction analysis (ARDRA). Due to inconsistencies in the results found by the identification methods employed, the 16S rRNA gene was partially sequenced and the result confirmed identity of L. curvatus, as predicted by ARDRA, which shows that this molecular technique is efficient in identifying the species. All isolates of L. curvatus were characterized by the molecular technique of random amplified polymorphic DNA (RAPD). In order to analyze the relationships existing between the isolates, taxonomic dendrograms were obtained based on molecular profile, what was suitable for the typing. The molecular techniques are efficient in the identification of Lactobacillus sp . isolates, which can be complementary or even substitute biochemical techniques. Thus, these molecular methods offer a fast and economic way for the identification and characterization of lactic acid bacterial with a potential use as starter cultures in the elaboration of handmade fermented products. Key words: 16S amplified ribosomal DNA restriction analysis (ARDRA), random amplified polymorphic DNA (RAPD), lactobacilli, microbial genetics.

Este artigo apresenta uma revisão bibliográfica a respeito das culturas iniciadoras de fermentação em vinhos. Fez-se uma abordagem a partir dos últimos cinco anos de pesquisa em temáticas pertinentes às áreas de Microbiologia, Biotecnologia, Ciências de Alimentos e Enologia com culturas iniciadoras. Foram revisados os processos de fermentação alcoólica, maloláctica, mista, bem como os métodos de estudo, com destaque para a Biotecnologia e as perspectivas de estudos. Palavras-chave: Culturas iniciadoras. Fermentação alcoólica. Fermentação maloláctica. Culturas mistas. Biotecnologia.

No presente estudo avaliou-se o potencial de aplicação da bacteriocina 2a produzida pelo Lactobacillus sake 2a em combinação com outras substâncias antimicrobianas na inibição de cepas de Salmonella isoladas de linguiça: S. Derby SD2, S. Enteritidis SE3, S. Hadar SH4, S. Panama SP5 e S. Typhimurium ST6. A partir de cultura de L. sake 2a em caldo MRS, obteve-se por extração ácida e concentração em liofilizador, um extrato protéico de bacteriocina de cerca de 500 UA/ml. Verificou-se que esse extrato protéico de bacteriocina 2a tem atividade contra Listeria monocytogenes Scott A Cmr Emr nos meios de cultura BHI, MRS e TSB com 0,1% de glicose, independente de temperatura e atmosfera de incubação. O extrato protéico de bacteriocina 2a foi utilizado só e em combinação com EDTA, ácido cítrico, ácido lático ou lisozima sobre "pool" de cepas de Salmonella. Todos os antimicrobianos testados apresentaram efeito inibidor contra Salmonella, no entanto, quando combinados à bacteriocina 2a esse efeito foi mais acentuado. Entre os tratamentos realizados, o que apresentou efeito mais potente na eliminação ou inibição de Salmonella foi a combinação bacteriocina 2a mais ácido lático 0,1%. Bacteriocina 2a também se mostrou mais eficiente que a nisina (usada como padrão) em combinações com lisozima e EDTA. O estudo permitiu verificar que existe um bom potencial de uso da bacteriocina 2a ou do L. sake 2a bac+ em alimentos em associação com os antimicrobianos ácido lático, ácido cítrico, EDTA ou lisozima. Entretanto, penas a combinação de antimicrobianos não é suficiente para eliminar ou inibir a multiplicação de Salmonella. As condições de temperatura, concentração e forma de aplicação dos tratamentos combinados podem variar e são pontos importantes quando se visa à ação direta sobre as células do patógeno ou quando este está associado a um substrato. The objective of this study was to analyse the potential of application of bacteriocin 2a produced by Lactobacillus sake 2a in combination with other antimicrobials substances on inhibition of strains of Salmonella isolated from raw Brazilian sausages (lingüiça): S. Derby SD2, S. Enteritidis SE3, S. Hadar SH4, S. Panama SP5 and S. Typhimurium ST6. Culture of L. sake 2a grown at 30ºC in MRS broth was used to obtain a cell-free supernatant after centrifugation. This cell-free supernatant was submitted to acid extraction method for bacteriocin and water reduction by liofilization process. After this, a final fraction was obtained and denominated proteic extract of bacteriocin 2a and had a final concentration of approximately 500 A.U/mL. Proteic extract of bacteriocin 2a obtained from cultures of L. sake 2a grown in broths: BHI, MRS, and TSB with 0.1% of glucose showed bactericidal effect against Listeria monocytogenes Scott A Cmr Emr, in any condition of temperature and atmosphere. The proteic extract of bacteriocin 2a was used alone and in combination with EDTA, citric acid, lactic acid or lyzozyme on pool of strains of Salmonella. All antimicrobials tested showed inhibitory effect against Salmonella, but in combination to bacteriocin 2a this effect was more efficient on inhibition or elimination of Salmonella. Bacteriocin 2a showed be more efficient than nisin when in association with lyzozyme and EDTA. This study was able to verify that exist a great potential of application of bacteriocin 2a and/or L. sake 2a bac+, in foods in combination with the antimicrobials: lactic acid, citric acid, EDTA or lyzozyme. However, the simple combination of these antimicrobials is not sufficient to eliminate or inhibit the growth of Salmonella. Temperature conditions, concentration of antimicrobials and form of application of treatments can change and they are very important points; mainly when the aim of the study is to evaluate the direct action of antimicrobials on cells of pathogen or action of these substances on pathogen into a specific substrate.

This work investigates the activities of nisin and gallic acid, used either alone or in combination, against Listeria monocytogenes Scott A CmrEmr. The antimicrobial activity was determined using agar diffusion tests. The growth profile was evaluated by measurements of optical density and the numbers of viable cells. Lipid peroxidation was measured by the thiobarbituric acid-reactive substances (TBARS) technique, and the levels of reduced glutathione (GSH) were determined by the 5,5-dithio-bis-2-nitrobenzoic acid (DTNB) method. Growth of the pathogen was inhibited by the combined use of nisin and gallic acid, with an inhibition zone of approximately 11 mm at concentrations of 8 mg/ml and 100 IU/ml, respectively. No significant reduction in the number of viable pathogen cells was observed after 18 hours of exposure to nisin and gallic acid. There was a significant increase in the GSH concentration, and a decrease in lipid peroxidation, when the pathogen was exposed to increasing concentrations of nisin and gallic acid, used either alone or in combination, for a period of 18 hours. It was concluded that the Listeria monocytogenes cell line studied was able to resist the action of oxidizing agents by increasing the synthesis of GSH.