Isolation and characterization of Bacillus thuringiensis from soils in contrasting agroecological zones of Ethiopia

Phenotypic and molecular methods were used to isolate and characterize B. thuringiensis from diverse agro-ecological zones of Ethiopia. Bioassays were used to test the insecticidal activity of B. thuringiensis strains against the major malaria vector, Anopheles arabiensis (Diptera).  B. thuringiensis were isolated from 32% of the total 503 soil samples collected from the 16 agro-ecological zones. All sequenced isolates were 99%–100% identical to each other and to B. thuringiensis entries in Genbank. B. thuringiensis with similar 16S rRNA gene sequences from these different zones were characterized with regard to maximum growth rate and temperature optima for growth to test if there was local adaptation in these functional traits. The result showed a narrow temperature range around 30°C for maximal growth rate, and there were no significant differences between agro-ecological zones. Of 110 Bacillus thuringiensis isolates analyzed for the presence of crystal protein genes,  7 tested positive for cry 4, cry 11, and cyt toxin genes. Sequencing of these genes in positive strains demonstrated 99–100 % homology to known mosquitocidal cry and cyt genes in Bacillus thuringiensis subsp. israelensis. The present study shows that this biotechnologically important species is wide spread in Ethiopian soils and that it does not demonstrate local adaptation to temperature regimes, at least not for basic functions such as growth-temperature response. Our finding also pointed the potential for exploiting this species in vector control programs.

Pole-to-pole biogeography of surface and deep marine bacterial communities

6 pages, 4 figuresThe Antarctic and Arctic regions offer a unique opportunity to test factors shaping biogeography of marine microbial communities because these regions are geographically far apart, yet share similar selection pressures. Here, we report a comprehensive comparison of bacterioplankton diversity between polar oceans, using standardized methods for pyrosequencing the V6 region of the small subunit ribosomal (SSU) rRNA gene. Bacterial communities from lower latitude oceans were included, providing a global perspective. A clear difference between Southern and Arctic Ocean surface communities was evident, with 78% of operational taxonomic units (OTUs) unique to the Southern Ocean and 70% unique to the Arctic Ocean. Although polar ocean bacterial communities were more similar to each other than to lower latitude pelagic communities, analyses of depths, seasons, and coastal vs. open waters, the Southern and Arctic Ocean bacterioplankton communities consistently clustered separately from each other. Coastal surface Southern and Arctic Ocean communities were more dissimilar from their respective open ocean communities. In contrast, deep ocean communities differed less between poles and lower latitude deep waters and displayed different diversity patterns compared with the surface. In addition, estimated diversity (Chao1) for surface and deep communities did not correlate significantly with latitude or temperature. Our results suggest differences in environmental conditions at the poles and different selection mechanisms controlling surface and deep ocean community structure and diversity. Surface bacterioplankton may be subjected to more short-term, variable conditions, whereas deep communities appear to be structured by longer water-mass residence time and connectivity through ocean circulationWe thank the members of field teams, shipboard crews, and logistics support personnel from all national polar programs involved in sample collection, without whom this study would not have been possible. The Census of Antarctic Marine Life, funded by the Sloan Foundation, facilitated this collaboration. Pyrosequencing was provided by the International Census of Marine Microbes (ICoMM) with financial support from a W. M. Keck Foundation award to the Marine Biological Laboratory in Woods Hole. Funding to support sample collection was provided by the Institut Français pour la Recherche et la Technologie Polaires (J.-F.G.); the Spanish Ministry of Education and Science (C.P.-A.); the New Zealand International Polar Year-Census of Antarctic Marine Life Project [Phases 1 (So001IPY) and 2 (IPY2007-01); to E.W.M.); the Natural Sciences and Engineering Council (NSERC) of Canada (C.L.); National Science Foundation Grants OPP-0124733 (to D.L.K.), ANT-0632389 (to A.E.M.), and ANT-0741409 (to P.L.Y.); and the Swedish Polar Research Secretariat (S.B.)Peer reviewe

ALCAM predicts future cardiovascular death in acute coronary syndromes: Insights from the PLATO trial

Background and aims - Activated leukocyte cell adhesion molecule (ALCAM) is upregulated during inflammation and involved in transmigration of leukocytes and T-cell activation. We hypothesized that ALCAM might be associated with recurrent events in patients with acute coronary syndromes (ACS). Methods - ALCAM was measured in serum obtained on admission, at discharge, 1 month and 6 months in a subgroup of 5165 patients admitted with ACS and included in the PLATelet inhibition and patient Outcomes (PLATO) trial (NCT00391872). The association between ALCAM and the composite endpoint and its components, including cardiovascular (CV) death, non-procedural spontaneous myocardial infarction (MI) or stroke during 1-year follow-up, was assessed by Cox proportional hazards models with incremental addition of clinical risk factors and biomarkers (including high-sensitivity troponin T, N-terminal pro−B-type natriuretic peptide and growth differentiation factor-15). Results - The median (Q1-Q3) concentration of ALCAM at admission was 97 (80–116) ng/mL. A 50% higher level of ALCAM on admission was associated with a hazard ratio (HR) of 1.16 (95% confidence interval [1.00–1.34] p = 0.043) for the composite endpoint in fully adjusted analysis, mainly driven by the association with CV death (HR 1.45 [1.16–1.82] p = 0.0012). Conclusions - In patients with ACS, admission level of ALCAM was independently associated with adverse outcome including CV death even after adjustment for established inflammatory and cardiac biomarkers

Correlative VIS-fluorescence and soft X-ray cryo-microscopy/tomography of adherent cells

Soft X-ray cryo-microscopy/tomography of vitreous samples is becoming a valuable tool in structural cell biology. Within the ‘water-window’ wavelength region (2.34–4.37 nm), it provides absorption contrast images with high signal to noise ratio and resolution of a few tens of nanometer. Soft X-rays with wavelengths close to the K-absorption edge of oxygen penetrate biological samples with thicknesses in the micrometer range. Here, we report on the application of a recently established extension of the transmission soft X-ray cryo-microscope (HZB TXM) at the beamline U41-XM of the BESSY II electron storage ring by an in-column epi-fluorescence and reflected light cryo-microscope. We demonstrate the new capability for correlative fluorescence and soft X-ray cryo-microscopy/tomography of this instrument along a typical life science experimental approach – the correlation of a fluorophore-tagged protein (pUL34-GFP of pseudorabies virus, PrV, the nuclear membrane-anchored component of the nuclear egress complex of the Herpesviridae which interacts with viral pUL31) in PrV pUL34-GFP/pUL31 coexpressing mammalian cells, with virus-induced vesicular structures in the nucleus, expanding the nucleoplasmic reticulum. Taken together, our results demonstrate new possibilities to study the role of specific proteins in substructures of adherent cells, especially of the nucleus in toto, accessible to electron microscopy in thinned samples only