Anti-herpes simplex virus 1 and immunomodulatory activities of a poly-γ- glutamic acid from Bacillus horneckiae strain APA of shallow vent origin

Applied Microbiology and Biotechnology - Herpes simplex virus type 1 (HSV-1) is responsible of common and widespread viral infections in humans through the world, and of rare, but extremely severe,...     

Comparison between Yeasts from Grape and Agave Musts for Traits of Technological interest

Summary In Mexico there are different alcoholic beverages produced from agave juices from different agave plants, which are cooked, fermented and distilled. For tequila production only Agave tequilana is allowed. In this study we compared yeast strains of different species from different origin (agave and grape juice) for parameters of technological interest, such as SO₂ and copper resistance, ethanol tolerance and enzymatic activities. All agave strains were found to be more resistant to SO₂ and agave non-Saccharomyces yeasts were more tolerant to ethanol, whereas grape strains exhibited positive results for β-glucosidase and β-xylosidase activities. As regards fermentations of Agave tequilana juice with ethanol added at different concentrations, only agave Saccharomyces strains were more tolerant to ethanol than grape strains.     

Pea powdery mildew <Emphasis Type="Italic">er1</Emphasis> resistance is associated to loss-of-function mutations at a <Emphasis Type="Italic">MLO</Emphasis> homologous locus

The powdery mildew disease affects several crop species and is also one of the major threats for pea (Pisum sativum L.) cultivation all over the world. The recessive gene er1, first described over 60 years ago, is well known in pea breeding, as it still maintains its efficiency as a powdery mildew resistance source. Genetic and phytopathological features of er1 resistance are similar to those of barley, Arabidopsis, and tomato mlo powdery mildew resistance, which is caused by the loss of function of specific members of the MLO gene family. Here, we describe the obtainment of a novel er1 resistant line by experimental mutagenesis with the alkylating agent diethyl sulfate. This line was found to carry a single nucleotide polymorphism in the PsMLO1 gene sequence, predicted to result in premature termination of translation and a non-functional protein. A cleaved amplified polymorphic sequence (CAPS) marker was developed on the mutation site and shown to be fully co-segregating with resistance in F₂ individuals. Sequencing of PsMLO1 from three powdery mildew resistant cultivars also revealed the presence of loss-of-function mutations. Taken together, results reported in this study strongly indicate the identity between er1 and mlo resistances and are expected to be of great breeding importance for the development of resistant cultivars via marker-assisted selection.     

Noemi Controls Production of Flavonoid Pigments and Fruit Acidity and Illustrates the Domestication Routes of Modern Citrus Varieties

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Molecular epidemiology of ESbetaL producing P. mirabilis strains from a long-term care and rehabilitation facility in Italy

We report the detection of multidrug resistant ESbetaL producing Proteus mirabilis isolates from a long-term care and rehabilitation facility (LTCRF) in Northern Italy. 53% of the collected P. mirabilis strains were ESbetaL producers. PCR and sequencing techniques confirmed the presence of the bla(TEM-92) and bla(CMY-16) resistance genes in 23/26 (88.5%) and 3/26 (11.5%) of the ESbetaL producers respectively. PFGE showed that the TEM-92 beta-lactamase producing isolates were not clonally related, indicating the presence of at least four different clonal lineages (A, B, C, D), whereas all the CMY-16 enzyme producers belonged in the same lineage. The bla(TEM-92) and bla(CYY-16) determinants were distributed in seven different wards, but in three of them they coexisted. Our results show that the most patients are co-colonized by ESbetaLs producing P. mirabilis strains at the time of admission to an LTCRF. An effective strategy to curtail the spread of ESbetaLs mediated resistance in LTCRFs could be to activate sourveillance programs to monitor routinely the entry of resistant bacteria.     

Reciprocal expression of the TNF family receptor herpes virus entry mediator and its ligand LIGHT on activated T cells: LIGHT down-regulates its own receptor

The TNF receptor (TNFR) family plays a central role in the development of the immune response. Here we describe the reciprocal regulation of the recently identified TNFR superfamily member herpes virus entry mediator (HVEM) (TR2) and its ligand LIGHT (TL4) on T cells following activation and the mechanism of this process. T cell activation resulted in down-regulation of HVEM and up-regulation of LIGHT, which were both more pronounced in CD8(+) than CD4(+) T lymphocytes. The analysis of HVEM and LIGHT mRNA showed an increase in the steady state level of both mRNAs following stimulation. LIGHT, which was present in cytoplasm of resting T cells, was induced both in cytoplasm and at the cell surface. For HVEM, activation resulted in cellular redistribution, with its disappearance from cell surface. HVEM down-regulation did not rely on de novo protein synthesis, in contrast to the partial dependence of LIGHT induction. Matrix metalloproteinase inhibitors did not modify HVEM expression, but did enhance LIGHT accumulation at the cell surface. However, HVEM down-regulation was partially blocked by a neutralizing mAb to LIGHT or an HVEM-Fc fusion protein during activation. As a model, we propose that following stimulation, membrane or secreted LIGHT binds to HVEM and induces receptor down-regulation. Degradation or release of LIGHT by matrix metalloproteinases then contributes to the return to baseline levels for both LIGHT and HVEM. These results reveal a self-regulating ligand/receptor system that contributes to T cell activation through the interaction of T cells with each other and probably with other cells of the immune system.     

Autotransporter-encoding sequences are phylogenetically distributed among Escherichia coli clinical isolates and reference strains

Autotransporters are secreted bacterial proteins exhibiting diverse virulence functions. Various autotransporters have been identified among Escherichia coli associated with intestinal or extraintestinal infections; however, the specific distribution of autotransporter sequences among a diversity of E. coli strains has not been investigated. We have validated the use of a multiplex PCR assay to screen for the presence of autotransporter sequences. Herein, we determined the presence of 13 autotransporter sequences and five allelic variants of antigen 43 (Ag43) among 491 E. coli isolates from human urinary tract infections, diarrheagenic E. coli, and avian pathogenic E. coli (APEC) and E. coli reference strains belonging to the ECOR collection. Clinical isolates were also classified into established phylogenetic groups. The results indicated that Ag43 alleles were significantly associated with clinical isolates (93%) compared to commensal isolates (56%) and that agn43K12 was the most common and widely distributed allele. agn43 allelic variants were also phylogenetically distributed. Sequences encoding espC, espP, and sepA and agn43 alleles EDL933 and RS218 were significantly associated with diarrheagenic E. coli strains compared to other groups. tsh was highly associated with APEC strains, whereas sat was absent from APEC. vat, sat, and pic were associated with urinary tract isolates and were identified predominantly in isolates belonging to either group B2 or D of the phylogenetic groups based on the ECOR strain collection. Overall, the results indicate that specific autotransporter sequences are associated with the source and/or phylogenetic background of strains and suggest that, in some cases, autotransporter gene profiles may be useful for comparative analysis of E. coli strains from clinical, food, and environmental sources.     

Long-chain acyl-CoA synthetase 6 preferentially promotes DHA metabolism

Previously we demonstrated that supplementation with the polyunsaturated fatty acids (PUFA) arachidonic acid (AA) or docosahexaenoic acid (DHA) increased neurite outgrowth of PC12 cells during differentiation, and that overexpression of rat acyl-CoA synthetase long-chain family member 6 (Acsl6, formerly ACS2) further increased PUFA-enhanced neurite outgrowth. However, whether Acsl6 overexpression enhanced the amount of PUFA accumulated in the cells or altered the partitioning of any fatty acids into phospholipids (PLs) or triacylglycerides (TAGs) was unknown. Here we show that Acsl6 overexpression specifically promotes DHA internalization, activation to DHA-CoA, and accumulation in differentiating PC12 cells. In contrast, oleic acid (OA) and AA internalization and activation to OA-CoA and AA-CoA were increased only marginally by Acsl6 overexpression. Additionally, the level of total cellular PLs was increased in Acsl6 overexpressing cells when the medium was supplemented with AA and DHA, but not with OA. Acsl6 overexpression increased the incorporation of [(14)C]-labeled OA, AA, or DHA into PLs and TAGs. These results do not support a role for Acsl6 in the specific targeting of fatty acids into PLs or TAGs. Rather, our data support the hypothesis that Acsl6 functions primarily in DHA metabolism, and that its overexpression increases DHA and AA internalization primarily during the first 24 h of neuronal differentiation to stimulate PL synthesis and enhance neurite outgrowth.     

Spatiotopic coding and remapping in humans

How our perceptual experience of the world remains stable and continuous in the face of continuous rapid eye movements still remains a mystery. This review discusses some recent progress towards understanding the neural and psychophysical processes that accompany these eye movements. We firstly report recent evidence from imaging studies in humans showing that many brain regions are tuned in spatiotopic coordinates, but only for items that are actively attended. We then describe a series of experiments measuring the spatial and temporal phenomena that occur around the time of saccades, and discuss how these could be related to visual stability. Finally, we introduce the concept of the spatio-temporal receptive field to describe the local spatiotopicity exhibited by many neurons when the eyes move.