Intake, total apparent digestibility, and microbial efficiency of sheep fed pineapple waste silage in different planes of nutrition

The study aimed to nutritionally evaluate the silage of pineapple crop waste in sheep feeding in different planes of nutrition (L). We used eight growing sheep and four male castrated adults, in individual metabolic cages distributed in a switchback design with two treatments and three periods. The treatments were the different planes of nutrition: L = MEI/Mm, MEI/1.5Mm, and MEI/2.5Mm, in which L = MEI/Mm, MEI is the energy amount of the feed intake and Mm is the maintenance. We performed a digestibility trial of the diet composed of silage of pineapple crop waste, ground corn, and soybean meal. Data were analyzed using regression analysis. Nutrient intake behaved linearly according to the increase in the L, except for organic matter, which presented a quadratic behavior. Planes of nutrition did not affect protein and fiber digestible fractions. However, digestible fractions of fat and non-fibrous carbohydrates (NFC) increased with L. The indigestible fractions displayed a quadratic behavior with an increase in the L. Regarding the microbial synthesis efficiency, we observed a linear decrease with the increase in L. Thus, the silage of pineapple crop waste is a feed very rich in NFC. Besides, silage of pineapple crop waste presented a good alternative roughage during forage shortages. Diet inclusion of 2.5x the maintenance does not compromise the sheep performance.(AU)

Effects of microbial conditioning and temperature on the leaf-litter shredding activity of Phylloicussp

Few studies try to explain the effects in tropical lotic ecosystems of an increase in water temperature on the shredding activity of invertebrate shredders, particularly in association with the quality of the leaf litter and the degree of litter conditioning. Therefore, the aims of this study were as follows: i) to better understand how this key invertebrate shredder group affects the decomposition of different species of leaf litter under gradual increases in temperature and microbial conditioning; and ii) to verify the possible consequences on leaf mass loss (LML). Three species of leaf litter were used in two experiments. Inexperiment I, the litters of three species (Protium spruceanum, Richeria grandisand Ingalaurina) at three conditioning levels (1, 7, 14 days) were tested under five different temperatures (20, 22, 24, 26 and28°C). In experiment II, the leaf litters of three species were used, without conditioning, under four temperatures (20, 22, 26 and27°C). The shredding performed by Phylloicussp. was largely dependent on the lignin and cellulose concentrations in each leaf species, independent of conditioning. The presence or absence of conditioning may cause the shredders to use different energy compensation strategies in response to the temperature increases.

Viabilidade de culturas probióticas em queijos tipo Minas Frescal / Viability of probiotic cultures in cheese Minas Frescal type

Os consumidores estão mais exigentes com a qualidade dos alimentos, e diante deste cenário, a adição de bactérias probióticas com apelo na saúde é uma tendência promissora, principalmente em produtos lácteos como queijo Minas Frescal. Objetivou-se verificar a viabilidade da adição de L. acidophilus LA-5 e B. animalis subsp. lactis BB-12 em queijo Minas Frescal, sob refrigeração a 4ºC, no 0, 7, 14 e 21 dias de armazenamento. As amostras foram inoculadas em ágar MRS e incubadas em anaerobiose a 35°C ± 2ºC por 48 horas. A população de células viáveis de bactérias probióticas se manteve nos níveis mínimos exigido pela legislação (10(8)-10(9) UFC g-1) durante todo o tempo de prateleira, o que evidencia a qualidade do queijo Minas Frescal como matriz alimentícia adequada e como um alimento potencialmente probiótico.(AU)

Viabilidade de culturas probióticas em queijos tipo Minas Frescal / Viability of probiotic cultures in cheese Minas Frescal type

Os consumidores estão mais exigentes com a qualidade dos alimentos, e diante deste cenário, a adição de bactérias probióticas com apelo na saúde é uma tendência promissora, principalmente em produtos lácteos como queijo Minas Frescal. Objetivou-se verificar a viabilidade da adição de L. acidophilus LA-5 e B. animalis subsp. lactis BB-12 em queijo Minas Frescal, sob refrigeração a 4ºC, no 0, 7, 14 e 21 dias de armazenamento. As amostras foram inoculadas em ágar MRS e incubadas em anaerobiose a 35°C ± 2ºC por 48 horas. A população de células viáveis de bactérias probióticas se manteve nos níveis mínimos exigido pela legislação (10(8)-10(9) UFC g-1) durante todo o tempo de prateleira, o que evidencia a qualidade do queijo Minas Frescal como matriz alimentícia adequada e como um alimento potencialmente probiótico.

Viability of probiotic bacteria in tropical mango juice and the resistance of the strains to gastrointestinal conditions simulated in vitro / Viabilidade de bactérias probióticas em suco tropical de manga e resistência das estirpes às condições gastrointestinais simuladas in vitro

This study evaluated the viability of Lactobacillus acidophilus La-05, Lactobacillus plantarum LP299v and Lactobacillus rhamnosus GG in tropical mango juice, the resistance of the strains to gastrointestinal conditions simulated in vitro and the microbiological, physicochemical and sensory characteristics of the products obtained. The viabilities of L. rhamnosus GG and L. plantarum LP299v were greater than 7.96 log CFU mL <->1 and 7.74 log CFU mL <->1, respectively, during the 28 days of storage at 8 ºC. However, there was a reduction (p < 0.05) in the viability of L. acidophilus La-5 after 21 days of storage, with counts of 3.81 log UFC mL <->1. The parameters of pH, total soluble solids, luminosity (L*) and the color coordinates, a* and b*, did not differ between the treatments. However, the pH and acidity varied during the storage time, probably due to the fermentative action of the microorganisms. For the in vitro gastrointestinal resistance test, there was a difference in the gastric phase for enteric phases I and II. The mean viability of the microorganisms in the gastric phase was 5.11 log CFU mL <->1, decreasing to 4.02 and 3.97 log CFU mL <->1 in enteric phases I and II, respectively. Juices containing L. rhamnosus GG and L. plantarum LP299 were evaluated sensorially, presenting good acceptability. The results suggest that the tropical mango juice was a good carrier matrix for L. rhamnosus GG and L. plantarum LP 299v, being well accepted and therefore an alternative for populations with dietary restrictions.(AU)

Este estudo avaliou a viabilidade de Lactobacillus acidophilus La-05, Lactobacillus plantarum LP299v e Lactobacillus rhamnosus GG em suco tropical de manga, a resistência das estirpes às condições gastrointestinais simuladas em ensaio in vitro e as características microbiológicas, físico-químicas e sensoriais dos produtos obtidos. A viabilidade de L. rhamnosus GG e L. plantarum LP299v foi superior a 7,96 log UFC mL <->1 e 7,74 log UFC mL <->1, respectivamente, ao longo dos 28 dias de armazenamento a 8 ºC. Entretanto, houve redução (p < 0,05) da viabilidade de L. acidophilus La-5 após 21 dias de armazenamento, com contagens de 3,81 log UFC mL <->1. pH, sólidos solúveis totais, luminosidade (L*) e as coordenadas a* e b* não diferiram entre os tratamentos. Entretanto, houve diferença de pH e acidez ao longo do tempo de armazenamento provavelmente devido a ação fermentativa dos microrganismos. No ensaio in vitro de resistência gastrointestinal, houve diferença da fase gástrica para as fases entéricas I e II. A média da viabilidade dos microrganismos na fase gástrica foi de 5,11 log UFC mL <->1, decaindo para 4,02 e 3,97 log UFC mL <->1 nas fases entéricas I e II, respectivamente. Os sucos contendo L. rhamnosus GG e L. plantarum LP299 foram avaliados sensorialmente, apresentando boa aceitabilidade. Os resultados de viabilidade e resistência ao trato gastrointestinal simulado in vitro sugerem que o suco tropical de manga é uma ótima matriz carreadora de L. rhamnosus GG e L. plantarum LP 299v, sendo bem aceitos e, portanto, uma alternativa para a população que apresenta restrições na dieta.(AU)

Influência das condições de armazenamento do vírus influenza na detecção por RT-qPCR e isolamento viral / Influence of storage conditions of influenza virus on virus detection by RT-qPCR and viral isolation

A infecção de suínos pelo vírus influenza causa perdas significativas na suinocultura e a doença tem implicações consideráveis para a saúde pública. Dessa forma, a rápida detecção viral em amostras biológicas de suínos é importante para a vigilância da influenza. Para o diagnóstico, as condições de manutenção das amostras biológicas (modo de acondicionamento, temperatura e período de acondicionamento), desde a colheita das amostras de suínos até o envio ao laboratório, podem interferir negativamente na detecção viral. Neste estudo foi analisada a viabilidade de uma amostra do vírus influenza A H1N1/2009 isolada de suínos, mantida em diferentes modos de acondicionamento (meio comercial UTM, meio in house VTM e sem meio de manutenção) e diferentes temperaturas (4, 23 e 37 °C) por um período de até 120 horas. As amostras foram avaliadas por RT-qPCR e isolamento em ovos embrionados. Foram observados efeitos significativos (p<0,05) para o modo e período de acondicionamento e da interação entre esses dois fatores com a carga viral. Dessa forma, as amostras biológicas enviadas para diagnóstico de influenza devem ser armazenadas, preferencialmente, em meio de manutenção viral a 4 °C e o tempo decorrido entre a colheita da amostra e a chegada ao laboratório deve ser de, no máximo, três dias.

Influenza virus infection in pigs causes significant losses for the swine industry and concerns for the public health. Therefore, rapid virus detection is important for influenza surveillance in pigs. Storage conditions (such as medium, temperature, and time) of the biological samples are very important for the diagnosis because they can negatively interfere with the viral detection. In this study, influenza virus viability was evaluated in different storage media (UTM commercial medium, "in house" VTM medium, and without storage medium), temperature (4, 23 and 37 °C), and storage time (up to 120 hours). Samples were evaluated by RT-qPCR and isolation in embryonated chicken eggs. Significant effects (p<0.05) were observed for the media and time besides the interaction between the two factors with the viral load. In conclusion, biological samples of pigs sent for influenza diagnosis should be stored, preferably in viral maintenance medium at 4 °C, and the time estimated between the sample collection until the arrival in the laboratory should be less than three days.

Influência das condições de armazenamento do vírus influenza na detecção por RT-qPCR e isolamento viral / Influence of storage conditions of influenza virus on virus detection by RT-qPCR and viral isolation

A infecção de suínos pelo vírus influenza causa perdas significativas na suinocultura e a doença tem implicações consideráveis para a saúde pública. Dessa forma, a rápida detecção viral em amostras biológicas de suínos é importante para a vigilância da influenza. Para o diagnóstico, as condições de manutenção das amostras biológicas (modo de acondicionamento, temperatura e período de acondicionamento), desde a colheita das amostras de suínos até o envio ao laboratório, podem interferir negativamente na detecção viral. Neste estudo foi analisada a viabilidade de uma amostra do vírus influenza A H1N1/2009 isolada de suínos, mantida em diferentes modos de acondicionamento (meio comercial UTM, meio in house VTM e sem meio de manutenção) e diferentes temperaturas (4, 23 e 37 °C) por um período de até 120 horas. As amostras foram avaliadas por RT-qPCR e isolamento em ovos embrionados. Foram observados efeitos significativos (p<0,05) para o modo e período de acondicionamento e da interação entre esses dois fatores com a carga viral. Dessa forma, as amostras biológicas enviadas para diagnóstico de influenza devem ser armazenadas, preferencialmente, em meio de manutenção viral a 4 °C e o tempo decorrido entre a colheita da amostra e a chegada ao laboratório deve ser de, no máximo, três dias.(AU)

Influenza virus infection in pigs causes significant losses for the swine industry and concerns for the public health. Therefore, rapid virus detection is important for influenza surveillance in pigs. Storage conditions (such as medium, temperature, and time) of the biological samples are very important for the diagnosis because they can negatively interfere with the viral detection. In this study, influenza virus viability was evaluated in different storage media (UTM commercial medium, "in house" VTM medium, and without storage medium), temperature (4, 23 and 37 °C), and storage time (up to 120 hours). Samples were evaluated by RT-qPCR and isolation in embryonated chicken eggs. Significant effects (p<0.05) were observed for the media and time besides the interaction between the two factors with the viral load. In conclusion, biological samples of pigs sent for influenza diagnosis should be stored, preferably in viral maintenance medium at 4 °C, and the time estimated between the sample collection until the arrival in the laboratory should be less than three days.(AU)

Viability of Campylobacter jejuni in the refrigerated samples of artificially contaminated pasteurized and UHT milks / Sobrevivência de Campylobacter jejuni em amostras de leite pasteurizado e UHT artificialmente contaminados e mantidas sob refrigeração

Campylobacter is the most prevalent etiologic agent of foodborne gastroenteritis worldwide. Although raw milk is an important source of infection, little is known about the consequences of milk recontamination. This study aimed at verifying the viability of Campylobacter jejuni in pasteurized and UHT milks stored under refrigeration. Both samples were divided into five portions of 100 mL, inoculated with 101 CFU.mL-1 of C. jejuni and stored at 4 C - 7 ºC for 48 h. The procedure was repeated using inoculations of 102, 103 and 104 CFU.mL-1. Aliquots were analyzed immediately after inoculation and after 24 and 48 h to evaluate C. jejuni viability. The microorganism their viability in all of samples. In pasteurized milk a reduction of 1 log cycle occurred after 24 h and low counts after 48 h. Probably, the reduction happened due to the occurrence of microbiota in this milk, which caused competition or inhibition of microorganism growth. UHT milk offered good conditions for bacteria survival in all of the periods. The consumption of contaminated milk, even stored under refrigeration might be a source of infection. Microorganism were more viable in UHT milk than in pasteurized one, probably owing to the absence of competing microorganisms.(AU)

Campylobacter é o agente etiológico mais prevalente em gastroenterites de causa alimentar no mundo. Apesar de o leite cru ser fonte de infecção, pouco se conhece sobre as consequências da recontaminação do leite. A viabilidade de Campylobacter jejuni foi avaliada em leites pasteurizados e UHT mantidos sob refrigeração. Ambos os leites foram divididos em cinco porções de 100 mL, inoculados com 101 UFC.mL-1 de C. jejuni e mantidos de 4 ºC a 7 ºC por 48 horas. Repetiu-se o procedimento, utilizando-se inoculações de 102, 103 e 104 UFC.mL-1. As alíquotas foram analisadas imediatamente após inoculação e depois de 24 e 48 h quanto à viabilidade de C. jejuni. O micro-organismo manteve-se viável em todas as amostras, porém no leite pasteurizado houve redução de 1 ciclo log nas contagens após 24 h e baixas contagens após 48 h. Provavelmente, a redução ocorreu pela presença de microbiota neste leite, que competiu ou inibiu o crescimento de C. jejuni. O leite UHT ofereceu boas condições de sobrevivência em todos os períodos. O consumo de leite contaminado, mesmo em armazenamento refrigerado, pode ser fonte de infecção. O micro-organismo manteve-se mais viável no leite UHT quando comparado ao pasteurizado, provavelmente pela ausência de outros micro-organismos competidores.(AU)

Desempenho produtivo de bovinos alimentados com cana-de-açúcar com diferentes níveis de concentrado / Productive performance of cattle fed sugarcane with different concentrate levels

Foram avaliados o consumo, as digestibilidades totais e ruminais e as taxas de digestão (kd) e de passagem (kp) ruminal dos nutrientes de dietas constituídas de cana-de-açúcar in naturae diferentes níveis de concentrado. Utilizaram-se cinco bovinos mestiços, fistulados no rúmen, com peso corporal inicial de 300±50kg, distribuídos em delineamento em quadrado latino 5x5. As dietas experimentais foram constituídas de: 1) 100% cana-de-açúcar in natura(CA); 2) 80% de CA + 20% de concentrado (C); 3) 60% de CA + 40% de C; 4) 40% de CA + 60% de C; e 5) 20% de CA + 80% de C. Os dados foram analisados utilizando-se o procedimento MIXED do SAS (versão 9.1), bem como análise de regressão e 5% como nível crítico de probabilidade para o erro tipo I. O consumo de matéria seca (MS), expresso em kg/dia ou g/kg de peso corporal foi influenciado (P<0,05) pelos níveis de concentrado. Os demais consumos calculados em kg/dia também foram influenciados (P<0,05) pelos níveis de concentrado, assim como os consumos de FDNcp, FDNi e NDT, expressos em g/kg de peso corporal. O pool (kg/dia) foi aumentado linearmente à medida que se elevaram os níveis de concentrado para MS. Comportamento similar foi observado para ki (h-1) da MS e da FDNcp. As taxas de digestão (kdh-1) da MS, da MO e da FDNcp aumentaram linearmente com a elevação dos níveis de concentrado na dieta. Estimaram-se máximos fluxos omasais (kg/dia) com 52,22 e 31,45% de concentrado na dieta, respectivamente, para MS e FDNi. A digestibilidade aparente (DA) da MS também foi influenciada pelos níveis de concentrado na dieta. As digestibilidades ruminais da MS e da FDN aumentaram linearmente (P<0,05) com a adição de níveis crescentes de concentrado. Conclui-se que níveis próximos de 65% de concentrado resultam em maior ingestão de energia em dietas contendo cana-de-açúcar.(AU)

An experiment was conducted to evaluate the feed intake, total and ruminal dietary component digestibility, ruminal digestion (kd) and passage rates (kp) of cattle fed sugarcane with different levels of concentrate. Five crossbred (Holstein x Zebu) with ruminal cannulas and initial body weight of 300±50kg were used in this experiment. Steers were assigned into a 5x5 Latin Square design balanced for residual effects. The experimental periods were divided into 16 d with 8 d for adaptation and 8 d for sample collection. Four treatments were used: 1) 100% fresh sugarcane (SC); 2) 80% SC + 20% concentrate (C); 3) 60% SC + 40% C; 4) 40% SC + 60% C; 5) 20% SC + 80% C. Urea/ammonium sulfate was used at 9:1 ratio to correct the protein level of sugarcane. A regression analysis was performed using the MIXED procedure. Dry matter intake (DMI) expressed either as kg/day or g/kg of BW was affected (P<0.05) by concentrate level and the maximum intake was estimated to be 63.61 and 75.04% of concentrate respectively. Intake (kg/day) of OM, CP, NDFap, TDN, iNDF, digestible NDFap (NDFapD), and NFC were affected by concentrate level (P<0.05) and their maximum intake was estimated to be 63.21; 63.78; 53.14; 64.31; 32.49; 88.47 e 55.46% of concentrate respectively. The ruminal pool size of DM and CP as well as ki (h-1) DM, CP, OM, NDFap, and NFC increased linearly as the dietary levels of concentrate increased. The ruminal digestion rate (kg h-1) of DM and NDFap as well as the passage rate (kg h-1) of CP increased linearly as the dietary levels of concentrate increased. The maximum omasal flux (kg/day) of DM and iNDF were estimated to be 52.22 and 31.45% of dietary concentrate respectively. Apparent digestibility of DM, EE, and NFC also increased linearly (P<0.05) with the increase of concentrate levels. Data suggest that levels up to 65% of concentrate result in greater energy intake by cattle fed sugarcane based diets.(AU)

Characteristics of dr1790 disruptant and its functional analysis in Deinococcus radiodurans

Deinococcus radiodurans (DR) is an extremophile that is well known for its resistance to radiation, oxidants and desiccation. The gene dr1790 of D. radiodurans was predicted to encode a yellow-related protein. The primary objective of the present study was to characterize the biological function of the DR1790 protein, which is a member of the ancient yellow/major royal jelly (MRJ) protein family, in prokaryotes. Fluorescence labeling demonstrated that the yellow-related protein encoded by dr1790 is a membrane protein. The deletion of the dr1790 gene decreased the cell growth rate and sensitivity to hydrogen peroxide and radiation and increased the membrane permeability of D. radiodurans. Transcript profiling by microarray and RT-PCR analyses of the dr1790 deletion mutant suggested that some genes that are involved in protein secretion and transport were strongly suppressed, while other genes that are involved in protein quality control, such as chaperones and proteases, were induced. In addition, the expression of genes with predicted functions that are involved in antioxidant systems, electron transport, and energy metabolism was significantly altered through the disruption of dr1790. Moreover, the results of proteomic analyses using 2-DE and MS also demonstrated that DR1790 contributed to D. radiodurans survival. Taken together, these results indicate that the DR1790 protein from the ancient yellow protein family plays a pleiotropic role in the survival of prokaryotic cells and contributes to the extraordinary resistance of D. radiodurans against oxidative and radiation stresses.(AU)

Effect of rosemary essential oil and modified-atmosphere packaging (MAP) on meat quality and survival of pathogens in poultry fillets

The effect of rosemary (Rosmarinus officinalis L.) essential oil (REO) and modified-atmosphere packaging (MAP) on the survival of certain pathogens (Salmonella Typhimurium and Listeria monocytogenes) in poultry fillets and on their meat quality during 7 days of refrigerated storage were investigated. Because REO at 0.05% and 0.1% had weak antibacterial activity and REO at 0.3%, 0.5% and 1.0% imparted unacceptable organoleptic properties, only REO at 0.2% was used to treat the poultry meat. The results showed that adding 0.2% REO to poultry fillets did not reduce the size of the population of S. Typhimurium and L. monocytogenes. However, REO treatment significantly decreased the L* (lightness) value and increased the a* (redness) value of stored fillets, and adding REO in combination with MAP reduced the level of lipid oxidation. In conclusion, in a suitable combination, REO can be applied to improve the quality of meat, but further studies should be conducted to determine the appropriate commercial level for different meat products.(AU)

Different methods to quantify Listeria monocytogenes biofilms cells showed different profile in their viability

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.(AU)

Evaluation of some pharmacological activities of Budmunchiamine - A isolated from Albizia amara

The present investigations were aimed to evaluate the antimicrobial and antioxidant efficacies of budmunchiamine-A (BUA) of Albizia amara. The activity-guided isolation leaded to isolate the bioactive compound budmunchiamine-A from alkaloid extract of A. amara. The budmunchiamine-A showed significant broad-spectrum antimicrobial activity with zone of inhibition (ZOI), minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) values varied from 7.3 to 24.5 mm, 0.95 to 62.5 μg/mL, and 1.9 to 250 μg/mL, respectively. The budmunchiamine-A exhibited moderate antioxidant activity with inhibitory concentration 50% (IC50) value of 400 μg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and percent inhibition of β-carotene/linoleic acid was 67.8%. The results suggest the possible use of budmunchiamine-A as a molecular entity for drug development in pharmaceutical industry.(AU)

Control of Listeria monocytogenes growth in soft cheeses by bacteriophage P100

The purpose of this study was to determine the effect of bacteriophage P100 on strains of Listeria monocytogenes in artificially inoculated soft cheeses. A mix of L. monocytogenes 1/2a and Scott A was inoculated in Minas Frescal and Coalho cheeses (approximately 10(5) cfu/g) with the bacteriophage added thereafter (8.3 x 10(7) PFU/g). Samples were analyzed immediately, and then stored at 10 ºC for seven days. At time zero, 30 min post-infection, the bacteriophage P100 reduced L. monocytogenes counts by 2.3 log units in Minas Frescal cheese and by 2.1 log units in Coalho cheese, compared to controls without bacteriophage. However, in samples stored under refrigeration for seven days, the bacteriophage P100 was only weakly antilisterial, with the lowest decimal reduction (DR) for the cheeses: 1.0 log unit for Minas Frescal and 0.8 log units for Coalho cheese. The treatment produced a statistically significant decrease in the counts of viable cells (p < 0.05) and in all assays performed, we observed an increase of approximately one log cycle in the number of viable cells of L. monocytogenes in the samples under refrigeration for seven days. Moreover, a smaller effect of phages was observed. These results, along with other published data, indicate that the effectiveness of the phage treatment depends on the initial concentration of L. monocytogenes, and that a high concentration of phages per unit area is required to ensure sustained inactivation of target pathogens on food surfaces.(AU)

Bacteriocinogenic Lactococcus lactis subsp: lactis DF04Mi isolated from goat milk: Evaluation of the probiotic potential

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties.

Antibacterial activity of alfa-terpineol may induce morphostructural alterations in Escherichia coli

The antibacterial effect of α-terpineol from Cinnamomum longepaniculatum (Gamble) N. Chao leaf essential oils were studied with special reference to the mechanism of inhibiting the standard strain of Escherichia coli (CMCC (B) 44102) growth at ultrastructural level. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) and time-kill curves of α-terpineol were determined; Escherichia coli was treated with α-terpineol and observed under a transmission electron microscope. The MIC and MBC values of α-terpineol were all 0.78 µL/mL, and time-kill curves showed the concentration-dependent. Under the transmission electron microscopy (TEM), Escherichia coli exposed to MIC levels of α-terpineol exhibited decreased cell size and irregular cell shape, cell wall and cell membrane were ruptured, nucleus cytoplasm was reduced and nuclear area gathered aside. Results suggest that α-terpineol has excellent antibacterial activity and could induce morphological changes of Escherichia coli.

Use Carum copticum essential oil for controlling the Listeria monocytogenes growth in fish model system

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.(AU)

Campylobacter jejuni in commercial eggs

This study evaluated the ability of Campylobacter jejuni to penetrate through the pores of the shells of commercial eggs and colonize the interior of these eggs, which may become a risk factor for human infection. Furthermore, this study assessed the survival and viability of the bacteria in commercial eggs. The eggs were placed in contact with wood shavings infected with C. jejuni to check the passage of the bacteria. In parallel, the bacteria were inoculated directly into the air chamber to assess the viability in the egg yolk. To determine whether the albumen and egg fertility interferes with the entry and survival of bacteria, we used varying concentrations of albumen and SPF and commercial eggs. C. jejuni was recovered in SPF eggs (fertile) after three hours in contact with contaminated wood shavings but not in infertile commercial eggs. The colonies isolated in the SPF eggs were identified by multiplex PCR and the similarity between strains verified by RAPD-PCR. The bacteria grew in different concentrations of albumen in commercial and SPF eggs. We did not find C. jejuni in commercial eggs inoculated directly into the air chamber, but the bacteria were viable during all periods tested in the wood shavings. This study shows that consumption of commercial eggs infected with C. jejuni does not represent a potential risk to human health.(AU)

Intake, digestibility, ruminal parameters, and microbial protein synthesis in crossbred steers fed diets based on Brachiaria grass silage and sorghum silage / Consumo, digestibilidade, parâmetros ruminais e síntese de proteína microbiana em novilhos cruzados alimentados com dietas a base de silagem de braquiária e silagem de sorgo

A trial was carried out with four Holstein x Nellore crossbred steers (225±22kg of BW) fitted with ruminal and abomasal cannulaes in a 4 x 4 Latin Square design to evaluate the intake and the total and partial apparent digestibilities of nutrients, ruminal parameters, and microbial synthesis. Diets consisted of 60 percent silage and 40 percent concentrate formulated to be isonitrogenous (12.5 percent of crude protein, dry matter basis). Treatments consisted of different proportions of Brachiaria brizantha grass silage and sorghum silage: 100:0; 67:33; 33:67, and 0:100 percent, respectively, on dry matter basis. The intake of dry matter, organic matter, crude protein, ether extract, non-fiber carbohydrates, and total digestible nutrients linearly increased (P<0.01) as levels of sorghum silage increased. The total apparent digestibility of dry matter, organic matter, and neutral detergent fiber linearly increased with sorghum silage levels (P<0.02). The highest ruminal NH3-N (13.63mg/dL) levels occurred at 2.94h post-feeding whereas the lowest ruminal pH (5.87) was measured at 5.21h post-feeding. Microbial efficiency was not affected (P>0.05) by the treatments. The use of 67 percent of sorghum silage and 33 percent of grass silage increased intake and digestibility of nutrients without affecting ruminal pH, ruminal NH3-N, and microbial efficiency.(AU)

Realizou-se um estudo com quatro novilhos cruzados Holandês x Nelore (225±22kg de peso vivo), canulados no rúmen e abomaso, distribuídos em quadrado latino 4 x 4 para avaliar o efeito de diferentes proporções de silagem de Braquiária brizantha e silagem de sorgo sobre o consumo e a digestibilidade dos nutrientes no trato digestório total e parcial, sobre os parâmetros ruminais e sobre a eficiência microbiana. As dietas continham 60 por cento de volumoso e 40 por cento de concentrado e foram formuladas para serem isonitrogenadas (12,5 por cento de proteína bruta na matéria seca). Os tratamentos consistiram em diferentes proporções de silagens de Brachiaria brizantha e de sorgo: 100:0; 67:33; 33:67 e 0:100 por cento, respectivamente ( por cento da matéria seca). O consumo de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, carboidratos não-fibrosos e nutrientes digestíveis totais aumentou linearmente (P<0,01) com o aumento da proporção de silagem de sorgo. A digestibilidade total da matéria seca, da matéria orgânica e da fibra em detergente neutro também aumentou linearmente (P<0,02) com o aumento da proporção de silagem de sorgo. A máxima concentração de N-amoniacal ruminal (13,63mg/dL) ocorreu 2,94 horas após a alimentação enquanto o menor pH foi observado às 5,21 horas após a alimentação. A eficiência microbina não foi afetada pelos tratamentos (P>0,05). O uso de 67 por cento de silagem de sorgo com 33 por cento de silagem de braquiária aumentou o consumo e a digestibilidade dos nutrientes sem afetar o pH e N-amoniacal ruminais, bem como a eficiência microbiana.(AU)

Viability of probiotic bacteria in tropical mango juice and the resistance of the strains to gastrointestinal conditions simulated in vitro / Viabilidade de bactérias probióticas em suco tropical de manga e resistência das estirpes às condições gastrointestinais simuladas in vitro

This study evaluated the viability of Lactobacillus acidophilus La-05, Lactobacillus plantarum LP299v and Lactobacillus rhamnosus GG in tropical mango juice, the resistance of the strains to gastrointestinal conditions simulated in vitro and the microbiological, physicochemical and sensory characteristics of the products obtained. The viabilities of L. rhamnosus GG and L. plantarum LP299v were greater than 7.96 log CFU mL

Este estudo avaliou a viabilidade de Lactobacillus acidophilus La-05, Lactobacillus plantarum LP299v e Lactobacillus rhamnosus GG em suco tropical de manga, a resistência das estirpes às condições gastrointestinais simuladas em ensaio in vitro e as características microbiológicas, físico-químicas e sensoriais dos produtos obtidos. A viabilidade de L. rhamnosus GG e L. plantarum LP299v foi superior a 7,96 log UFC mL