• Differences in the aromatic domain of homologous streptococcal fibronectin-binding proteins trigger different cell invasion mechanisms and survival rates.

      Rohde, Manfred; Graham, Rikki M; Branitzki-Heinemann, Katja; Borchers, Patricia; Preuss, Claudia; Schleicher, Ina; Zähner, Dorothea; Talay, Susanne R; Fulde, Marcus; Dinkla, Katrin; et al. (2011-03)
      Group A streptococci (GAS, Streptococcus pyogenes) and Group G streptococci (GGS, Streptococcus dysgalactiae ssp. equisimilis) adhere to and invade host cells by binding to fibronectin. The fibronectin-binding protein SfbI from GAS acts as an invasin by using a caveolae-mediated mechanism. In the present study we have identified a fibronectin-binding protein, GfbA, from GGS, which functions as an adhesin and invasin. Although there is a high degree of similarity in the C-terminal sequence of SfbI and GfbA, the invasion mechanisms are different. Unlike caveolae-mediated invasion by SfbI-expressing GAS, the GfbA-expressing GGS isolate trigger cytoskeleton rearrangements. Heterologous expression of GfbA on the surface of a commensal Streptococcus gordonii and purified recombinant protein also triggered actin rearrangements. Expression of a truncated GfbA (lacking the aromatic domain) and chimeric GfbA/SfbI protein (replacing the aromatic domain of SfbI with the GfbA aromatic domain) on S. gordonii or recombinant proteins alone showed that the aromatic domain of GfbA is responsible for different invasion mechanisms. This is the first evidence for a biological function of the aromatic domain of fibronectin-binding proteins. Furthermore, we show that streptococci invading via cytoskeleton rearrangements and intracellular trafficking along the classical endocytic pathway are less persistence than streptococci entering via caveolae.
    • Digitoxin metabolism by rat liver microsomes.

      Schmoldt, A; Benthe, H F; Haberland, G; Poser, W; Poser, S; Eickhoff, K; Piggott, S M; Kerkut, G A; Walker, R J (1975-09-01)
    • Distribution and Antigenicity of Fibronectin Binding Proteins (SfbI and SfbII) of Streptococcus pyogenes Clinical Isolates from the Northern Territory, Australia

      Goodfellow, Alison M.; Hibble, Megan; Talay, Susanne R.; Kreikemeyer, Bernd; Currie, Bart J.; Sriprakash, Kadaba S.; Chhatwal, Gursharan S. (American Society for Microbiology, 2000-01)
    • DnaK from Bifidobacterium animalis subsp. lactis is a surface-exposed human plasminogen receptor upregulated in response to bile salts.

      Candela, Marco; Centanni, Manuela; Fiori, Jessica; Biagi, Elena; Turroni, Silvia; Orrico, Catia; Bergmann, Simone; Hammerschmidt, Sven; Brigidi, Patrizia; Department of Pharmaceutical Sciences, University of Bologna, Italy. (2010-06)
      Bifidobacterium animalis subsp. lactis lives in the gastrointestinal tract of most mammals, including humans. Recently, for the probiotic strain B. animalis subsp. lactis BI07, a dose-dependent plasminogen-binding activity was demonstrated and five putative plasminogen-binding proteins were identified. Here we investigated the role of surface DnaK as a B. animalis subsp. lactis BI07 plasminogen receptor. DnaK was visualized on the bacterial cell surface by transmission electron microscopy. The His-tagged recombinant DnaK protein showed a high affinity for human plasminogen, with an equilibrium dissociation constant in the nanomolar range. The capability to tolerate physiological concentrations of bile salts is a crucial feature for an intestinal symbiont micro-organism. By proteome analysis we demonstrated that the long-term exposure of B. animalis subsp. lactis BI07 to bile salts results in the upregulation of important surface plasminogen receptors such as DnaK and enolase. Moreover, adaptation of B. animalis subsp. lactis BI07 to physiological concentrations of bile salts significantly increased its capacity to interact with the host plasminogen system. By enhancing the bacterial capacity to interact with the host plasminogen, the gut bile environment may facilitate the colonization of the human host by B. animalis subsp. lactis BI07.
    • DNase Sda1 provides selection pressure for a switch to invasive group A streptococcal infection.

      Walker, Mark J; Hollands, Andrew; Sanderson-Smith, Martina L; Cole, Jason N; Kirk, Joshua K; Henningham, Anna; McArthur, Jason D; Dinkla, Katrin; Aziz, Ramy K; Kansal, Rita G; et al. (2007-08)
      Most invasive bacterial infections are caused by species that more commonly colonize the human host with minimal symptoms. Although phenotypic or genetic correlates underlying a bacterium's shift to enhanced virulence have been studied, the in vivo selection pressures governing such shifts are poorly understood. The globally disseminated M1T1 clone of group A Streptococcus (GAS) is linked with the rare but life-threatening syndromes of necrotizing fasciitis and toxic shock syndrome. Mutations in the GAS control of virulence regulatory sensor kinase (covRS) operon are associated with severe invasive disease, abolishing expression of a broad-spectrum cysteine protease (SpeB) and allowing the recruitment and activation of host plasminogen on the bacterial surface. Here we describe how bacteriophage-encoded GAS DNase (Sda1), which facilitates the pathogen's escape from neutrophil extracellular traps, serves as a selective force for covRS mutation. The results provide a paradigm whereby natural selection exerted by the innate immune system generates hypervirulent bacterial variants with increased risk of systemic dissemination.
    • Effects of ionizing radiation on the survival of bacterial spares in artificial martia regolith

      Moeller, Ralf; Rohde, Manfred; Reitz, Günther; Department of Medical Microbiology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, D-38124 Braunschweig, Germany (Science Direct, 2010-04)
    • Entry and intracellular survival of group B streptococci in J774 macrophages.

      Valenti-Weigand, P; Benkel, P; Rohde, Manfred; Chhatwal, G S (1996-07)
    • Exocytotic process as a novel model for mineralization by osteoblasts in vitro and in vivo determined by electron microscopic analysis.

      Rohde, Manfred; Mayer, H; Department of Microbial Pathogenesis, Helmholtz Center for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany. manfred.rohde@helmholtz-hzi.de (2007-05)
      The process of biomineralization has been examined during osteoblastic differentiation of bone marrow stroma cells (BMSCs) from embryonic chick in culture and in periosteum itself by a number of different techniques including transmission and scanning electron microscopy. In cell culture of BMSCs at days 20-25, crystals were accumulated extracellularly in the collagen matrix, resulting in large plate-like crystallites and noncollagen associated on the culture disk surface. In contrast, up to days 10-18, mainly intracellular mineralization was visible by numerous needle-like crystal structures in the cell cytoplasm and in vacuoles. After 20-30 days, the crystal content of these vacuoles is released, most probably by membrane fusion to the outside of the cells. Energy-dispersive X-ray analysis (EDX), electron spectroscopic imaging, and electron energy loss spectroscopy demonstrated that Ca, O, and P are located in the intra- and extracellular needle-like crystals. From EDX spectra a Ca/P ratio of 1.3 was estimated for the intracellular structures and a Ca/P ratio of 1.5, for the extracellular material (for comparison, the Ca/P ratio in tibiae is 1.6). X-ray diffraction and quantitative infrared spectral analyses also demonstrated an increase of crystalline bone apatite along the mineralization process. In addition to the finding in vitro, the presence of intracellular needle-like crystals in vacuoles could be demonstrated in vivo in osteoblastic cells of the periosteum in tibia of day 11. The results are in favor of a novel model for mineralization by osteoblasts, in which amorphous Ca/P material is directly secreted via an exocytotic process from vacuoles of the osteoblast, deposited extracellularly, propagated into the collagen fibril matrix, and matured to hydroxyapatite.
    • The FbaB-type fibronectin-binding protein of Streptococcus pyogenes promotes specific invasion into endothelial cells.

      Amelung, Silva; Nerlich, Andreas; Rohde, Manfred; Spellerberg, Barbara; Cole, Jason N; Nizet, Victor; Chhatwal, Gursharan S; Talay, Susanne R; Department of Medical Microbiology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany. (2011-08)
      Invasive serotype M3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering from invasive streptococcal disease and have the potential to invade primary human endothelial cells (EC) via a rapid and efficient mechanism. FbaB protein, the fibronectin-binding protein expressed by M3 S. pyogenes, was herein identified as a potent invasin for EC. By combining heterologous gene expression with allelic replacement, we demonstrate that FbaB is essential and sufficient to trigger EC invasion via a Rac1-dependent phagocytosis-like uptake. FbaB-mediated uptake follows the classical endocytic pathway with lysosomal destination. FbaB is demonstrated to be a streptococcal invasin exhibiting EC tropism. FbaB thus initiates a process that may contribute to the deep tissue tropism and spread of invasive S. pyogenes isolates into the vascular EC lining.
    • first detection of trimethoprim resistance determinant dfrG in Streptococcus pyogenes clinical isolates in India.

      Bergmann, René; Sagar, Vivek; Nitsche-Schmitz, D Patric; Chhatwal, Gursharan S (2012-10)
    • Genetic variation in group A streptococci.

      McMillan, David J; Sriprakash, Kadaba S; Chhatwal, Gursharan S; Department of Microbial Pathogenesis, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany. (2007-11)
      Group A streptococcus (GAS) is responsible for a range of human diseases that vary in their clinical manifestations and severity. While numerous virulence factors have been described, the way these factors interact to promote different streptococcal diseases is less clear. In order to identify multifactorial relationships between GAS and the human host, novel high-throughput techniques such as microarrays are necessary. We have performed comparative studies using custom-designed virulence arrays to enhance our understanding of the high degree of genotypic variation that occurs in streptococci. This study has pointed to mobile genetic elements as the major agents that promote variation. Our results show that multiple combinations of genes might bring about similar clinical pictures. This adds further complexity to the intricate relationship between pathogen and host.
    • The genome sequence of Methanohalophilus mahii SLP(T) reveals differences in the energy metabolism among members of the Methanosarcinaceae inhabiting freshwater and saline environments.

      Spring, Stefan; Scheuner, Carmen; Lapidus, Alla; Lucas, Susan; Glavina Del Rio, Tijana; Tice, Hope; Copeland, Alex; Cheng, Jan-Fang; Chen, Feng; Nolan, Matt; et al. (2010)
      Methanohalophilus mahii is the type species of the genus Methanohalophilus, which currently comprises three distinct species with validly published names. Mhp. mahii represents moderately halophilic methanogenic archaea with a strictly methylotrophic metabolism. The type strain SLP(T) was isolated from hypersaline sediments collected from the southern arm of Great Salt Lake, Utah. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,012,424 bp genome is a single replicon with 2032 protein-coding and 63 RNA genes and part of the Genomic Encyclopedia of Bacteria and Archaea project. A comparison of the reconstructed energy metabolism in the halophilic species Mhp. mahii with other representatives of the Methanosarcinaceae reveals some interesting differences to freshwater species.
    • Genome sequence of the Antarctic rhodopsins-containing flavobacterium Gillisia limnaea type strain (R-8282T)

      Riedel, Thomas; Held, Brittany; Nolan, Matt; Lucas, Susan; Lapidus, Alla; Tice, Hope; Del Rio, Tijana Glavina; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; et al. (2013-02-07)
    • Genome sequence of the filamentous, gliding Thiothrix nivea neotype strain (JP2(T)).

      Lapidus, Alla; Nolan, Matt; Lucas, Susan; Glavina Del Rio, Tijana; Tice, Hope; Cheng, Jan-Fang; Tapia, Roxanne; Han, Cliff; Goodwin, Lynne; Pitluck, Sam; et al. (2011-12-31)
      Thiothrix nivea (Rabenhorst 1865) Winogradsky 1888 (Approved Lists 1980) emend. Larkin and Shinabarger 1983 is the type species of the genus Thiothrix in the family Thiotrichaceae. The species is of interest not only because of its isolated location in the yet to be genomically characterized region of the tree of life, but also because of its life-style with gliding gonidia, the multilayer sheath, rosettes, and the embedded sulfur granules. Strain JP2(T) is the neotype strain of the species which was first observed by Rabenhorst in 1865 and later reclassified by Winogradsky in 1888 into the then novel genus Thiothrix. This is the first completed (improved-high-quality-draft) genome sequence to be published of a member of the family Thiotrichaceae. The genome in its current assembly consists of 15 contigs in four scaffolds with a total of 4,691,711 bp bearing 4,542 protein-coding and 52 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.
    • Genome sequence of the flexirubin-pigmented soil bacterium Niabella soli type strain (JS13-8T)

      Anderson, Iain; Munk, Christine; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Tice, Hope; Glavina Del Rio, Tijana; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; et al. (2012)
    • Genome sequence of the moderately thermophilic halophile Flexistipes sinusarabici strain (MAS10).

      Lapidus, Alla; Chertkov, Olga; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Han, Cliff; Goodwin, Lynne; et al. (2011-10-15)
      Flexistipes sinusarabici Fiala et al. 2000 is the type species of the genus Flexistipes in the family Deferribacteraceae. The species is of interest because of its isolated phylogenetic location in a genomically under-characterized region of the tree of life, and because of its origin from a multiply extreme environment; the Atlantis Deep brines of the Red Sea, where it had to struggle with high temperatures, high salinity, and a high concentrations of heavy metals. This is the fourth completed genome sequence to be published of a type strain of the family Deferribacteraceae. The 2,526,590 bp long genome with its 2,346 protein-coding and 53 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.
    • Genome sequence of the moderately thermophilic sulfur-reducing bacterium Thermanaerovibrio velox type strain (Z-9701T) and emended description of the genus Thermanaerovibrio

      Palaniappan, Krishna; Meier-Kolthoff, Jan P.; Teshima, Hazuki; Nolan, Matt; Lapidus, Alla; Tice, Hope; Del Rio, Tijana Glavina; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; et al. (2014-01-06)
    • Genome sequence of the moderately thermophilic, amino-acid-degrading and sulfur-reducing bacterium Thermovirga lienii type strain (Cas60314(T)).

      Göker, Markus; Saunders, Elisabeth; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; et al. (2012-05-25)
      Thermovirga lienii Dahle and Birkeland 2006 is a member of the genus Thermovirga in the genomically moderately well characterized phylum 'Synergistetes'. Members of this relatively recently proposed phylum 'Synergistetes' are of interest because of their isolated phylogenetic position and their diverse habitats, e.g. from humans to oil wells. The genome of T. lienii Cas60314(T) is the fifth genome sequence (third completed) from this phylum to be published. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 1,999,646 bp long genome (including one plasmid) with its 1,914 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.