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Background: Salmonella enterica serovar Infantis (Salmonella Infantis) is a zoonotic, ubiquitous and foodborne pathogen of worldwide distribution. Despite Brazil's relevance as a major meat exporter, few studies were conducted to characterize strains of this serovar by genomic analyses in this country. Therefore, this study aimed to assess the diversity of 80 Salmonella Infantis strains isolated from veterinary, food and human sources in Brazil between 2013 and 2018 by comparative genomic analyses. Additional genomes of non-Brazilian countries (n = 18) were included for comparison purposes in some analyses. Methods: Analyses of whole-genome multi-locus sequence typing (wgMLST), using PGAdb-builder, and of fragmented genomes, using Gegenees, were conducted to compare the 80 Brazilian strains to the 18 non-Brazilian genomes. Pangenome analyses and calculations were performed for all Salmonella Infantis genomes analyzed. The presence of prophages was determined using PHASTER for the 80 Brazilian strains. The genome plasticity using BLAST Ring Image Generator (BRIG) and gene synteny using Mauve were evaluated for 20 selected Salmonella Infantis genomes from Brazil and ten from non-Brazilian countries. Unique orthologous protein clusters were searched in ten selected Salmonella Infantis genomes from Brazil and ten from non-Brazilian countries. Results: wgMLST and Gegenees showed a high genomic similarity among some Brazilian Salmonella Infantis genomes, and also the correlation of some clusters with non-Brazilian genomes. Gegenees also showed an overall similarity >91% among all Salmonella Infantis genomes. Pangenome calculations revealed an open pangenome for all Salmonella Infantis subsets analyzed and a high gene content in the core genomes. Fifteen types of prophages were detected among 97.5% of the Brazilian strains. BRIG and Mauve demonstrated a high structural similarity among the Brazilian and non-Brazilian isolates. Unique orthologous protein clusters related to biological processes, molecular functions, and cellular components were detected among Brazilian and non-Brazilian genomes. Conclusion: The results presented using different genomic approaches emphasized the significant genomic similarity among Brazilian Salmonella Infantis genomes analyzed, suggesting wide distribution of closely related genotypes among diverse sources in Brazil. The data generated contributed to novel information regarding the genomic diversity of Brazilian and non-Brazilian Salmonella Infantis in comparison. The different genetically related subtypes of Salmonella Infantis from Brazil can either occur exclusively within the country, or also in other countries, suggesting that some exportation of the Brazilian genotypes may have already occurred.

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The photoluminescence (PL) of monolayer tungsten disulfide (WS2) is locally and electrically controlled using the nonplasmonic tip and tunneling current of a scanning tunneling microscope (STM). The spatial and spectral distribution of the emitted light is determined using an optical microscope. When the STM tip is engaged, short-range PL quenching due to near-field electromagnetic effects is present, independent of the sign and value of the bias voltage applied to the tip-sample tunneling junction. In addition, a bias-voltage-dependent long-range PL quenching is measured when the sample is positively biased. We explain these observations by considering the native n-doping of monolayer WS2 and the charge carrier density gradients induced by electron tunneling in micrometer-scale areas around the tip position. The combination of wide-field PL microscopy and charge carrier injection using an STM opens up new ways to explore the interplay between excitons and charge carriers in two-dimensional semiconductors.

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Pertussis is a highly contagious respiratory disease caused by Bordetella pertussis, a Gram-negative bacterium described over a century ago. Despite broad vaccine coverage and treatment options, the disease is remerging as a public health problem especially in infants and older children. Recent data indicate re-emergence of the disease is related to bacterial resistance to immune defences and decreased vaccine effectiveness, which obviously suggests the need of new effective vaccines and drugs. In an attempt to contribute with solutions to this great challenge, bioinformatics tools were used to genetically comprehend the species of these bacteria and predict new vaccines and drug targets. In fact, approaches were used to analysis genomic plasticity, gene synteny and species similarities between the 20 genomes of Bordetella pertussis already available. Furthermore, it was conducted reverse vaccinology and docking analysis to identify proteins with potential to become vaccine and drug targets, respectively. The analyses showed the 20 genomes belongs to a homogeneous group that has preserved most of the genes over time. Besides that, were found genomics islands and good proteins to be candidates for vaccine and drugs. Taken together, these results suggests new possibilities that may be useful to develop new vaccines and drugs that will help the prevention and treatment strategies of pertussis disease caused by these Bordetella strains. Communicated by Ramaswamy H. Sarma.

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The genus Rickettsia belongs to the Proteobacteria phylum and these bacteria infect animals and humans causing a range of diseases worldwide. The genus is divided into 4 groups and despite the public health threat and the knowledge accumulated so far, the mandatory intracellular bacteria behaviour and limitation for in vitro culture makes it difficult to create new vaccines and drug targets to these bacteria. In an attempt to overcome these limitations, pan-genomic approaches has used 47 genomes of the genus Rickettsia, in order to describe species similarities and genomics islands. Moreover, we conducted reverse vaccinology and docking analysis aiming the identification of proteins that have great potential to become vaccine and drug targets. We found out that the bacteria of the four Rickettsia groups have a high similarity with each other, with about 90 to 100% of identity. A pathogenicity island and a resistance island were predicted. In addition, 8 proteins were also predicted as strong candidates for vaccine and 9 as candidates for drug targets. The prediction of the proteins leads us to believe in a possibility of prospecting potential drugs or creating a polyvalent vaccine, which could reach most strains of this large group of bacteria.Communicated by Ramaswamy H. Sarma.

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Normal moveout (NMO) velocity is used in seismic data processing to correct the data from the moveout effect. This velocity depends on the medium above the reflector and it is estimated from the adjustment of a hyperbolic function that approximates the reflection time. This approximation is reasonable for media formed by isotropic layers. For deeper exploration targets, which effectively behave as anisotropic media, the NMO velocity estimate from the hyperbolic approximation becomes imprecise. One possibility is the use of non-hyperbolic approximations for the reflection time and deeming the medium to be anisotropic. However, these approximations make the NMO velocity estimation a more complex problem, since the anisotropic parameters are unknown. In this study the NMO velocities for a vertical transverse isotropy medium are estimated using two non-hyperbolic reflection time approaches. For comparing the two methodologies that estimate NMO velocity, a 2-D dataset from Jequitinhonha Basin is used and it presents anisotropic behavior. The results show that this approach produces more consistent results than the conventional approach, which ignores the anisotropy of the medium.

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Here, we describe a new species of Amphisbaena with two precloacal pores from open Cerrado areas of the municipality of Arenópolis, in the Brazilian state of Goiás. The new species differs from other South American amphisbaenids by the folllowing combination of characters: (1) snout rounded in dorsal view and slightly convex in lateral view; (2) two precloacal pores; (3) 161-176 dorsal half-annuli; and (4) 12-15 tail annuli. Our molecular phylogenetic analysis retrieved a monophyletic Amphisbaena silvestrii group, with A. silvestrii positioned as the sister-group of a clade formed by Amphisbaena anaemariae and the new species described herein. Members of the A. silvestrii group including A. neglecta and A. crisae not added in our phylogenetic analysis are characterized by a relatively small body, two precloacal pores, body coloration with dark and light areas, and lack of specializations on the cephalic or caudal shields. We present a key for two-pored species of Amphisbaena.

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Basic hydrolysis of a dichloromethane extract of Stevia lucida yielded (4R,5S,7R,9R,10R,11R)-7,9-dihydroxylongipin-2-en-1-one (1), which was oxidized and subjected to acidic conditions to generate the new seco-moreliane derivative 3. The structure of 3 was established based on NMR data interpretation and confirmed computationally. A plausible mechanism for the carbocationic rearrangement of the trione 2 to the seco-moreliane 3 was supported by DFT computations.

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Using the time-dependent density functional theory, we perform quantum calculations of the electron dynamics in small charged metallic nanoparticles (clusters) of spherical geometry. We show that the excess charge is accumulated at the surface of the nanoparticle within a narrow layer given by the typical screening distance of the electronic system. As a consequence, for nanoparticles in vacuum, the dipolar plasmon mode displays only a small frequency shift upon charging. We obtain a blue shift for positively charged clusters and a red shift for negatively charged clusters, consistent with the change of the electron spill-out from the nanoparticle boundaries. For negatively charged clusters, the Fermi level is eventually promoted above the vacuum level leading to the decay of the excess charge via resonant electron transfer into the continuum. We show that, depending on the charge, the process of electron loss can be very fast, on the femtosecond time scale. Our results are of great relevance to correctly interpret the optical response of the nanoparticles obtained in electrochemistry, and demonstrate that the measured shift of the plasmon resonances upon charging of nanoparticles cannot be explained without account for the surface chemistry and the dielectric environment.

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The purpose of the present study was to examine how children's postural control is affected by different visual cues. Sixteen children, ages 8 and 12 years, and eight adults participated in the study. Each was asked to stand upright inside a moving room, which oscillated at 0.2 Hz, while facing the frontal wall at two distances: 75 and 150 cm, under monocular and binocular vision conditions. Vision manipulation induced corresponding body sway in all participants, but vision effect was the smallest in the monocular vision condition, at the greater distance (150 cm) from the front wall. More importantly, however, the influence of visual manipulation on body sway was age-dependent, with the younger children showing less visually induced body sway than the older children and adults. This aging effect was more dramatic in the monocular vision condition. These results suggest that development of the visual system is not fully completed until the age of 12 years and that eye movement and binocular vision might play an important role in how visual cues are coupled to body sway.

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O objetivo deste estudo foi avaliar o desempenho do controle postural e a obtenção de informação somatosensorial de idosos diabéticos praticantes e não praticantes de atividade física. Participaram deste estudo dez idosos diabéticos ativos (62±4,4 anos) (GDA), dez diabéticos sedentários (65,5±7,4 anos) (GDS) e dez idosos sadios ativos (63,2±4,5anos) (GCA), que realizaram avaliação de sensibilidade cutânea e detecção de movimento passivo, nas articulações do tornozelo e joelho, e de manutenção da postura nas posturas bipedal e tandem stance. Os resultados indicaram pior desempenho do GDS na detecção do movimento passivo e do controle postural, nas condições de maior exigência das tarefas. Especificamente, o GDS apresentou maior amplitude média de oscilação, na direção médio-lateral, durante manutenção da postura ereta na posição tandem stance. No teste de sensibilidade ao movimento passivo, o GDS precisou de um maior deslocamento angular para perceber o movimento das articulações do joelho e tornozelo. Nenhuma diferença foi observada entre os GDA e GCA. Estes resultados indicam que as alterações decorrentes do diabetes deterioram a capacidade de obtenção de informação sensorial e funcionamento do sistema de controle postural. Entretanto, essas alterações podem ser minimizadas com a prática regular de atividade física, fazendo com que pacientes diabéticos ativos apresentem o mesmo desempenho que idosos ativos não diabéticos.

The purpose of this study was to assess the performance of the sensory and postural control somatosensory information in elderly diabetics practitioners and non-practitioners of physical activity programs. Participated of this study ten active diabetics (62±4.4 year-old) (GAD), ten sendentary diabetics (65.5±4.5 year-old) (GSD), and ten healthy elderlies (63.2±4.5 year-old) (GHE), who were submitted to skin sensitivity and passive motion detection tests, in the ankle and knee joints, and maintenance of upright bipodal and tandem stance position. The results indicate worst performance of the GDS in the assessment of passive movement detection and postural control, in the more demanding tasks. Specifically, the GSD showed higher mean sway amplitude, in the medial-lateral direction in the tandem stance position. In the passive motion detection test, the GSD needed a larger angular displacement in order to detect the passive motion of the knee and ankle passive motion. No differences were observed between GAD and GHE. These results indicate that the changes due to diabetes decrease the capacity of obtaining sensory information and the functioning of the postural control system. However, these changes can be minimized with regular physical activity.

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The immune response of relatively small, endogamous populations is of special interest, because they may differ from those of large, ethnically diverse, urban groups. As a contribution to this area of investigation, we tested 99 individuals from two Brazilian native populations for two T-cell receptor gene segments (TCRBV3S1 and TCRBV18) and 241 subjects from eight tribes of this ethnic group in relation to the chemokine receptor CCR5delta32 allele. Differences in TCRBV3S1 and TCRBV18 prevalences of the Amerindians in relation to European- and African-derived individuals were not marked. We confirmed the absence of the CCR5delta32 allele in most groups, its presence in the Mura and Kaingang, probably because of European gene introgression.

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The antiviral activity of polysaccharide fractions obtained from water extracts of the red seaweed Nothogenia fastigiata was investigated. Fraction F6, corresponding to a sulphated xylomannan, was found to inhibit efficiently the replication of herpes simplex virus type 1 (HSV-1). Furthermore, F6 selectively inhibited the replication of several other enveloped viruses including herpes simplex virus type 2, human cytomegalovirus (HCMV), respiratory syncytial virus, influenza A and B virus, Junin and Tacaribe virus and simian immunodeficiency virus. F6 was only weakly active against human immunodeficiency virus type 1 and 2. The mode of action of F6 against HSV-1 and HCMV could be ascribed to an inhibitory effect on virus adsorption.

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A glycopeptide isolated from the high plant Melia azedarach L. (meliacine) inhibits the in vitro replication of several RNA and DNA animal viruses. Interferon (IFN) production was depressed greatly in meliacine treated L929 cells and primary mouse embryo fibroblast cultures (MEF) induced with Newcastle disease virus (NDV) or poly(rI).poly(rC). This action was observed when meliacine was added before, simultaneously or early after induction with poly(rI).poly(rC) or NDV. In addition, accumulation of acid-resistant IFN was strongly diminished in adult mice treated intraperitoneally with meliacine. Though meliacine causes a strong inhibition of IFN both in vitro and in vivo, we do not know how selectively it affects the IFN system.

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A partially purified plant inhibitor (Meliacin) isolated from Melia azedarach L induced in cells a refractory state to virus infection. Meliacin was active in a large variety of continuous and/or primary cell cultures. A state of maximum virus resistance was achieved after 2 h of incubation and was maintained for at least 15 h; later on it declined but it was fully regained after a second pulse of Meliacin. Interferon was not detected in the supernatant of cells treated with Meliacin and a measurable increase in ds-RNA dependent protein kinase activity was not observed in extracts of Meliacin-treated cells. The antiviral state was not transferred by either extracellular fluid or direct cell-to-cell contact. An active cell metabolism was required for Meliacin action, which was partially reversed in the presence of actinomycin D. It appears that Meliacin is not an interferon-like substance, which induces an antiviral state based on a still unexplained mechanism.

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Crude extracts from fresh green leaves of Melia azedarach L contain an antiviral factor (FAV) able to inhibit the replication of several animal viruses, e.g. Polio, VSV, HSV, FMDV, Sindbis, Junín, Pichinde and Tacaribe in Vero or BHK-21 cells. Crude preparations were subjected to different steps of purification like chromatography on Sephadex G-100 and DEAE-Sephadex. The antiviral activity of G-100 and DEAE fractions was fully conserved, whereas contaminating proteins were lost. Two types of cytotoxicity tests were performed with the different fractions. Two-fold serial dilutions of each of them were added to preformed monolayers of Vero or BHK-21 cells and cellular viability was tested. While crude extracts were toxic at low dilutions (less than or equal to 1:10), G-100 and DEAE fractions were not. The other cytotoxicity assay consisted in seeding the cells in the presence of different concentrations of each fraction. G-100 fraction affected cell growth at low dilutions (less than or equal to 1:5), while DEAE fraction did not. It should be remarked that the purification procedure rendered a partial purified DEAE fraction with an increased specific activity (antiviral activity/mg of protein). It is concluded that an antiviral factor devoid of toxicity exists in M. azedarach L extracts, which exhibited a broad spectrum of antiviral activity.

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Crude extracts from fresh green leaves of Melia azedarach L contain an antiviral factor (FAV) able to inhibit the replication of several animal viruses, e.g. Polio, VSV, HSV, FMDV, Sindbis, Junín, Pichinde and Tacaribe in Vero or BHK-21 cells. Crude preparations were subjected to different steps of purification like chromatography on Sephadex G-100 and DEAE-Sephadex. The antiviral activity of G-100 and DEAE fractions was fully conserved, whereas contaminating proteins were lost. Two types of cytotoxicity tests were performed with the different fractions. Two-fold serial dilutions of each of them were added to preformed monolayers of Vero or BHK-21 cells and cellular viability was tested. While crude extracts were toxic at low dilutions (less than or equal to 1:10), G-100 and DEAE fractions were not. The other cytotoxicity assay consisted in seeding the cells in the presence of different concentrations of each fraction. G-100 fraction affected cell growth at low dilutions (less than or equal to 1:5), while DEAE fraction did not. It should be remarked that the purification procedure rendered a partial purified DEAE fraction with an increased specific activity (antiviral activity/mg of protein). It is concluded that an antiviral factor devoid of toxicity exists in M. azedarach L extracts, which exhibited a broad spectrum of antiviral activity.

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Crude extracts from fresh green leaves of Melia azedarach L contain an antiviral factor (FAV) able to inhibit the replication of several animal viruses, e.g. Polio, VSV, HSV, FMDV, Sindbis, Junín, Pichinde and Tacaribe in Vero or BHK-21 cells. Crude preparations were subjected to different steps of purification like chromatography on Sephadex G-100 and DEAE-Sephadex. The antiviral activity of G-100 and DEAE fractions was fully conserved, whereas contaminating proteins were lost. Two types of cytotoxicity tests were performed with the different fractions. Two-fold serial dilutions of each of them were added to preformed monolayers of Vero or BHK-21 cells and cellular viability was tested. While crude extracts were toxic at low dilutions (less than or equal to 1:10), G-100 and DEAE fractions were not. The other cytotoxicity assay consisted in seeding the cells in the presence of different concentrations of each fraction. G-100 fraction affected cell growth at low dilutions (less than or equal to 1:5), while DEAE fraction did not. It should be remarked that the purification procedure rendered a partial purified DEAE fraction with an increased specific activity (antiviral activity/mg of protein). It is concluded that an antiviral factor devoid of toxicity exists in M. azedarach L extracts, which exhibited a broad spectrum of antiviral activity.