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Braunschweig, Germany

Sulesco T.,Moldova Academy of Sciences | Volkova T.,National Academy of Sciences of Belarus | Tomazatos A.,Bernhard Nocht Institute for Tropical Medicine | von Thien H.,Bernhard Nocht Institute for Tropical Medicine | And 3 more authors.
Parasitology Research | Year: 2016

During the last two decades, Belarus faces an increase of human cases of Dirofilaria (Nematoda, Spirurida, Onchocercidae) infections. However, comprehensive analyses explaining this development and the identification of mosquito vector species are missing. Here, we present results using temperature data from Belarus and show that the annual number of human Dirofilaria cases is significantly correlated with the yearly average temperatures (Spearman’s rho = 0.49, p < 0.05) and the average sum of potential Dirofilaria transmission days (Spearman’s rho = 0.46, p < 0.05), suggesting that autochthonous transmission is at least in part responsible for the increasing number of clinical Dirofilaria cases in the country. In addition, 467 female mosquitoes were collected from different sampling sites in the regions of Brest and Minsk, which were analyzed by molecular methods for the presence of Dirofilaria repens and Dirofilaria immitis DNA, respectively. Two pools (5.56 %) were tested positive for Dirofilaria (estimated infection rate per 100 specimens = 0.44, 95 % confidence interval = 0.08–1.43), comprising one Anopheles claviger s.l. pool that was positive for D. repens and one Culex pipiens s.l./Culex torrentium pool positive for D. immitis DNA. This, to our knowledge, is the first molecular evidence for the presence of Dirofilaria in mosquitoes from Belarus, suggesting a high probability of autochthonous Dirofilaria transmission in the country. © 2016 Springer-Verlag Berlin Heidelberg Source


Buschart A.,University of Bremen | Buschart A.,Center for Infection Research | Sachs S.,University of Bremen | Chen X.,University of Bremen | And 4 more authors.
Molecular Plant-Microbe Interactions | Year: 2012

Azoarcus sp. strain BH72 is an endophytic betaproteobacterium able to colonize rice roots without induction of visible disease symptoms. BH72 possesses one polar flagellum. The genome harbors three copies of putative fliC genes, generally encoding the major structural protein flagellin. It is not clear whether, in endophytic interactions, flagella mediate endophytic competence or act as MAMPs (microbe-asscociated molecular patterns) inducing plant defense responses. Therefore, possible functions of the three FliC proteins were investigated. Only fliC3 was found to be highly expressed in pure culture and in association with rice roots and to be required for bacterial motility, suggesting that it encodes the major flagellin. Endophytic colonization of rice roots was significantly reduced in the in-frame deletion mutant, while the establishment of microcolonies on the root surface was not affected. Moreover, an elicitation of defense responses related to FliC3 was not observed. In conclusion, our data support the hypothesis that FliC3 does not play a major role as a MAMP but is required for endophytic colonization in the Azoarcus-rice interaction, most likely for spreading inside the plant. © 2012 The American Phytopathological Society. Source


George S.E.,University of Tubingen | Nguyen T.,University of Tubingen | Nguyen T.,Center for Infection Research | Geiger T.,University of Tubingen | And 5 more authors.
Molecular Microbiology | Year: 2015

Bacteria respond to ever-changing environments through several adaptive strategies. This includes mechanisms leading to a high degree of phenotypic variability within a genetically homogeneous population. In Staphylococcus aureus, the capsular polysaccharide (CP) protects against phagocytosis, but also impedes adherence to endothelial cells and/or matrix proteins. We analysed the regulation of core biosynthesis genes (capA-P) necessary for CP synthesis using single-cell assays (immunofluorescence and promoter-activity). In persistent human carriers, we found a distinct subpopulation of nasal S.aureus to be CP positive. In vitro, cap expression is also heterogeneous and strongly growth-phase dependent. We asked whether this peculiar expression pattern (earlyOff/lateHeterogen) is orchestrated by the quorum system Agr. We show that the Agr-driven effector molecule RNAIII promotes cap expression largely via inactivation of the repressor Rot. High NaCl, deletion of CodY or Sae also resulted in higher cap expression but did not change the earlyOFF/lateHeterogen expression pattern. Activity of the quorum system itself is largely homogenous and does not account for the observed heterogeneity of cap expression or the strictly growth phase dependent expression. Our findings are in contrast to the prevailing view that quorum sensing is the main driving force for virulence gene expression when bacterial cell densities increase. © 2015 John Wiley & Sons Ltd. Source


Teutschbein J.,Leibniz Institute of Plant Biochemistry | Gross W.,University of Cologne | Gross W.,Verbraucherschutz e.V. | Nimtz M.,Center for Infection Research | And 4 more authors.
Journal of Biological Chemistry | Year: 2010

We have isolated an enzyme classified as chlorogenate: glucarate caffeoyltransferase (CGT) from seedlings of tomato (Solanum lycopersicum) that catalyzes the formation of caffeoylglucarate and caffeoylgalactarate using chlorogenate (5-O-caffeoylquinate) as acyl donor. Peptide sequences obtained by trypsin digestion and spectrometric sequencing were used to isolate the SlCGT cDNA encoding a protein of 380 amino acids with a putative targeting signal of 24 amino acids indicating an entry of the SlCGT into the secretory pathway. Immunogold electron microscopy revealed the localization of the enzyme in the apoplastic space of tomato leaves. Southern blot analysis of genomic cDNA suggests that SlCGT is encoded by a single-copy gene. The SlCGT cDNA was functionally expressed in Nicotiana benthamiana leaves and proved to confer chlorogenate-dependent caffeoyltransferase activity in the presence of glucarate. Sequence comparison of the deduced amino acid sequence identified the protein unexpectedly as a GDSL lipase-like protein, representing a new member of the SGNH protein superfamily. Lipases of this family employ a catalytic triad of Ser-Asp-His with Ser as nucleophile of the GDSL motif. Site-directed mutagenesis of each residue of the assumed respective SlCGT catalytic triad, however, indicated that the catalytic triad of the GDSL lipase is not essential for SlCGT enzymatic activity. SlCGT is therefore the first example of a GDSL lipase-like protein that lost hydrolytic activity and has acquired a completely new function in plant metabolism, functioning in secondary metabolism as acyltransferase in synthesis of hydroxycinnamate esters by employing amino acid residues different from the lipase catalytic triad. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc. Source


Weiss K.,Mittelhessen University of Applied Sciences | Salzig D.,Mittelhessen University of Applied Sciences | Roder Y.,Mittelhessen University of Applied Sciences | Gerstenberger J.,Mittelhessen University of Applied Sciences | And 8 more authors.
American Journal of Biochemistry and Biotechnology | Year: 2013

Recombinant measles viruses are currently tested in clinical trials as oncolytic agent to be applied in cancer therapy. Contrary to their use as vaccine where 103 infectious virus particles per dose are needed, for cancer therapy 109 virus particles should be provided per dose. This leads to other challenges for the production process when compared to vaccine production. This study presents measles virus stability with regard to conditions during production and storage of the virus. Relevant process parameters such as temperature (4-37°C), pH (pH 4-11), conductivity (1.5 to 137.5 mS cm-1) and oxygen partial pressure were analyzed. The infectivity of measles virus particles decreased highly at 37 and 32°C, while at 22 and 4°C it remained stable for several hours or even days, respectively. The thermal inactivation reactions followed first order kinetics and the thermodynamic parameters enthalpy and entropy were estimated. Towards changes in pH measles virus particles were very sensitive, while no inactivation could be observed with varying conductivity. Measles virus incubation at an oxygen partial pressure of 100% did not lead to any loss of infectivity. The results show which parameters should be considered and controlled strongly in the production process to further raise measles virus yields for the high amount needed in cancer therapy approaches. © 2013 Science Publication. Source

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