Complete genome analysis of Tequatrovirus ufvareg1, a Tequatrovirus species inhibiting Escherichia coli O157:H7.

Introduction: Bacteriophages infecting human pathogens have been considered potential biocontrol agents, and studying their genetic content is essential to their safe use in the food industry. Tequatrovirus ufvareg1 is a bacteriophage named UFV-AREG1, isolated from cowshed wastewater and previously tested for its ability to inhibit Escherichia coli O157:H7. Methods: T. ufvareg1 was previously isolated using E. coli O157:H7 (ATCC 43895) as a bacterial host. The same strain was used for bacteriophage propagation and the one-step growth curve. The genome of the T. ufvareg1 was sequenced using 305 Illumina HiSeq, and the genome comparison was calculated by VIRIDIC and VIPTree. Results: Here, we characterize its genome and compare it to other Tequatrovirus. T. ufvareg1 virions have an icosahedral head (114 x 86 nm) and a contracted tail (117 x 23 nm), with a latent period of 25 min, and an average burst size was 18 phage particles per infected E. coli cell. The genome of the bacteriophage T. ufvareg1 contains 268 coding DNA sequences (CDS) and ten tRNA genes distributed in both negative and positive strains. T. ufvareg1 genome also contains 40 promoters on its regulatory regions and two rho-independent terminators. T. ufvareg1 shares an average intergenomic similarity (VIRIDC) of 88.77% and an average genomic similarity score (VipTree) of 88.91% with eight four reference genomes for Tequatrovirus available in the NCBI RefSeq database. The pan-genomic analysis confirmed the high conservation of Tequatrovirus genomes. Among all CDS annotated in the T. ufvareg1 genome, there are 123 core genes, 38 softcore genes, 94 shell genes, and 13 cloud genes. None of 268 CDS was classified as being exclusive of T. ufvareg1. Conclusion: The results in this paper, combined with other previously published findings, indicate that T. ufvareg1 bacteriophage is a potential candidate for food protection against E. coli O157:H7 in foods.

Kombuchas from Green and Black Tea Modulate the Gut Microbiota and Improve the Intestinal Health of Wistar Rats Fed a High-Fat High-Fructose Diet.

The Western diet can negatively affect the gut microbiota and is associated with metabolic disorders. Kombucha, a tea fermented by a symbiotic culture of bacteria and yeast (SCOBY), is known for its bioactive properties and has become popular in the last years. In this study, we evaluated the effects of regular kombucha consumption on the gut microbiota and on outcomes related to the intestinal health of Wistar rats fed a high-fat high-fructose diet. After eight weeks receiving a standard diet (AIN-93M) (n = 10) or a high-fat and high-fructose diet (HFHF) (n = 30) to induce metabolic disorders, the animals were subdivided into four groups: AIN-93M (n = 10); HFHF (n = 10); GTK (HFHF + green tea kombucha (n = 10); and BTK (HFHF + black tea kombucha; n = 10) for 10 weeks. Although body composition did not differ among the groups, the HFHF diet was associated with metabolic alterations, and stimulated the growth of gram-negative bacteria such as Proteobacteria and Bacteroides. Kombucha ingestion could somewhat modulate the gut microbiota, attenuating the effects of a Western diet by increasing propionate production and favoring the growth of beneficial bacteria, such as Adlercreutzia in the GTK group. Our results suggest that regular kombucha consumption may be beneficial to intestinal health, which can be mostly attributed to its high content and diversity of phenolic compounds.

Black tea kombucha: Physicochemical, microbiological and comprehensive phenolic profile changes during fermentation, and antimalarial activity.

This study shows the changes in physicochemical and microbiological composition, and in the phenolic profile of black tea kombucha during fermentation. In addition, the antimalarial potential of the kombucha was evaluated. Ultra-performance liquid chromatography-mass spectrometry multiplex analysis (UPLC-MSE) results revealed a 1.7 log2 fold-change increase in phenolics with the fermentation time, with emphasis on the increase of phenolic acids (0.3 log2 fold-change). Over time there was degradation of flavonoids such as nepetin, hesperidin and catechin 5-O-gallate, to the detriment of the increase in phenolic acids such as gallic acid and cinnamic acid. In addition, black tea kombucha presented antiplasmodic activity against the 3D7 (sensitive chloroquine) and W2 (resistant to chloroquine) strains. Therefore, important changes in the black tea kombucha phenolic profile take place during fermentation, which may help in the development of kombuchas with higher bioactive potential and contribute to a better understanding of the kombucha fermentation process.

Chia (Salvia hispanica L.) Flour and Oil Ameliorate Metabolic Disorders in the Liver of Rats Fed a High-Fat and High Fructose Diet.

We hypothesized that the consumption of chia (Salvia hispanica L.) flour (CF) and chia oil (CO) improves metabolic disorders in the liver of Wistar rats (Rattus norvegicus domestica) fed a high-fat and high-fructose (HFHF) diet. The animals were fed a HFHF diet (n = 30) or AIN93-M standard diet (n = 10) for eight weeks. After this period, the animals fed HFHF were divided into three groups (n = 10): HFHF diet, HFHF plus 14.7% of CF, and HFHF plus 4% of CO. Histological and biochemical analyses, gene expression, protein levels related to inflammation, and oxidative stress were evaluated in the liver. The HFHF diet caused lipogenesis, liver steatosis, oxidative stress, and inflammation in the animals. The CF and CO intake increased the liver total antioxidant capacity and superoxide dismutase, decreased nitric oxide levels and liver steatosis. Furthermore, the CF and CO led to the upregulation of Cpt1a and Adipor2, respectively, whereas CF downregulated Srebf1. CO intake decreased blood glucose, triglycerides, and the animals' body weight. Chia did not show effects on mitigating liver pro-inflammatory status, which it may indicate occurs later. The addition of chia into an unbalanced diet is a good and relevant strategy to reduce liver metabolic disorders caused by the high consumption of fructose and saturated fat.

Kombuchas from green and black teas reduce oxidative stress, liver steatosis and inflammation, and improve glucose metabolism in Wistar rats fed a high-fat high-fructose diet.

The aim of this study was to evaluate the effect of green and black tea kombuchas consumption on adiposity, lipid and glucose metabolism, liver steatosis, oxidative stress, and inflammation in Wistar rats fed a high-fat high-fructose (HFHF) diet. Wistar rats, after 8 weeks to induce metabolic alterations, were divided into an AIN-93M control group, HFHF control group, green tea kombucha + HFHF diet (GTK group), and black tea kombucha + HFHF diet (BTK group), for 10 weeks. The kombuchas improved glucose metabolism, plasma total antioxidant capacity, superoxide dismutase activity, and decreased nitric oxide concentration. Moreover, both kombuchas reduced systemic inflammation by decreasing the neutrophil/lymphocyte ratio (NLR), reduced the total adipose tissue and blood triglyceride, and reverted liver steatosis (from grade 2 to 1), besides the modulation of genes related to adipogenesis and ß-oxidation. Therefore, kombuchas from green and black teas have bioactive properties that can help control metabolic alterations induced by the HFHF diet.

Kombuchas from green and black teas have different phenolic profile, which impacts their antioxidant capacities, antibacterial and antiproliferative activities.

UPLC-QTOF-MSE phenolic profile of kombuchas produced from the fermentation of green tea or black tea at 25 °C for 10 days was investigated along with the determination of their antioxidant capacities, antibacterial and antiproliferative activities. Overall, 127 phenolic compounds (70.2% flavonoids, 18.3% phenolic acids, 8.4% other polyphenols, 2.3% lignans and 0.8% stilbenes) were identified, with 103 phenolic compounds reported for the first time in kombuchas. A greater diversity and abundance of phenolic compounds was detected in black tea kombucha, which resulted in a higher antioxidant capacity. However, the green tea kombucha was the only one that presented antibacterial activity against all the bacteria tested and an increased antiproliferative activity against the cancer cell lines, which was attributed to the presence of catechins among the most abundant phenolic compounds and verbascoside as an exclusive compound. Thus, the type of tea used in the kombucha production interferes in its bioactive composition and properties.

Detecção de Listeria, Salmonella e Klebsiella em serviço de alimentação hospitalar / Detection of Listeria, Salmonella and Klebsiella in a hospital food service

OBJETIVO: A presença de Listeria monocytogenes, Salmonella sp. e Klebsiella sp. em dietas enterais e em ambientes, utensílios e equipamentos de preparo de alimentos em serviço de alimentação hospitalar, foi o objetivo desta pesquisa. MÉTODOS: A contaminação de ambientes, utensílios e equipamentos de preparo de alimentos em serviço de alimentação hospitalar por Listeria monocytogenes, Salmonella sp. e Klebsiella sp. foi avaliada em 50 amostras coletadas pela técnica de swab. Quatro amostras de dietas enterais também foram analisadas. Colônias típicas de bactérias do gênero Listeria foram isoladas de dieta enteral em ágar Oxford e a identificação da espécie L. monocytogenes foi feita por testes bioquímicos e imunológicos. RESULTADOS: A presença de Salmonella foi detectada em dieta enteral e identificada como S. rissen por sorologia. Pela relevância como agente causador de infecções hospitalares, bactérias do gênero Klebsiella foram pesquisadas e isoladas em ágar seletivo MacConkey-inositol-carbenicilina. K. pneumoniae foi encontrada em equipamento e utensílio e K. oxytoca em ambiente, equipamento e dieta enteral. Os isolados de L. monocytogenes apresentaram resistência apenas ao antibiótico cefoxitina e os do gênero Klebsiella foram resistentes a ampicilina e amoxilina. S. rissen foi sensível aos 13 antibióticos avaliados. CONCLUSAO: A contaminação de 11 por cento das amostras analisadas com pelo menos um dos patógenos, alerta para a necessidade de implantação de um rigoroso sistema de controle de qualidade nas áreas de manipulação dos alimentos, a fim de aumentar a segurança alimentar dos pacientes hospitalizados.