• Kroppenstedtia eburnea gen. nov., sp. nov., a thermoactinomycete isolated by environmental screening, and emended description of the family Thermoactinomycetaceae Matsuo et al. 2006 emend. Yassin et al. 2009.

      von Jan, Mathias; Riegger, Nicole; Pötter, Gabriele; Schumann, Peter; Verbarg, Susanne; Spröer, Cathrin; Rohde, Manfred; Lauer, Bettina; Labeda, David P; Klenk, Hans-Peter (2011-09)
      A Gram-positive, spore-forming, aerobic, filamentous bacterium, strain JFMB-ATE(T), was isolated in 2008 during environmental screening of a plastic surface in grade C in a contract manufacturing organization in southern Germany. The isolate grew at temperatures of 25-50 °C and at pH 5.0-8.5, forming ivory-coloured colonies with sparse white aerial mycelia. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the family Thermoactinomycetaceae, except that the cell-wall peptidoglycan contained LL-diaminopimelic acid, while all previously described members of this family display this diagnostic diamino acid in meso-conformation. The DNA G+C content of the novel strain was 54.6 mol%, the main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol, and the major menaquinone was MK-7. The major fatty acids had saturated C₁₄-C₁₆ branched chains. No diagnostic sugars were detected. Based on the chemotaxonomic results and 16S rRNA gene sequence analysis, the isolate is proposed to represent a novel genus and species, Kroppenstedtia eburnea gen. nov. sp. nov. The type strain is JFMB-ATE(T) ( = DSM 45196(T)  = NRRL B-24804(T)  = CCUG 59226(T)).
    • Live Helicobacter pylori in the root canal of endodontic-infected deciduous teeth.

      Hirsch, Christian; Tegtmeyer, Nicole; Rohde, Manfred; Rowland, Marion; Oyarzabal, Omar A; Backert, Steffen; Department of Paediatric Dentistry, University School of Dental Medicine, University of Leipzig, Nuernberger Straße 57, 04103, Leipzig, Germany. Christian.Hirsch@medizin.uni-leipzig.de (2012-08)
      Many polymerase chain reaction (PCR)-based studies have shown that Helicobacter pylori DNA is prevalent in the oral cavity, but reports on the isolation of live bacteria are extremely rare. Thus, it is still unclear whether H. pylori can indeed survive in the oral environment.
    • Localization of the C3-Like ADP-ribosyltransferase from Staphylococcus aureus during bacterial invasion of mammalian cells.

      Molinari, Gabriella; Rohde, Manfred; Wilde, Christian; Just, Ingo; Aktories, Klaus; Chhatwal, Gursharan S; Department of Microbial Pathogenesis, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany. (2006-06)
      The C3stau2 exoenzyme from Staphylococcus aureus is a C3-like ADP-ribosyltransferase which possesses no specific receptor-binding domain or translocation unit required for entry in target cells where its substrate is located. Here we show that C3stau2 can reach its target after invasion of staphylococci in eukaryotic cells without needing translocation.
    • M protein-mediated plasminogen binding is essential for the virulence of an invasive Streptococcus pyogenes isolate.

      Dinkla, K; Cole, J N; Cork, A J; Maamary, P G; McArthur, J D; Chhatwal, G S; Walker, M J; School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia. (2008-08)
      The human protease plasmin plays a crucial role in the capacity of the group A streptococcus (GAS; Streptococcus pyogenes) to initiate invasive disease. The GAS strain NS88.2 was isolated from a case of bacteremia from the Northern Territory of Australia, a region with high rates of GAS invasive disease. Mutagenesis of the NS88.2 plasminogen binding M protein Prp was undertaken to examine the contribution of plasminogen binding and cell surface plasmin acquisition to virulence. The isogenic mutant NS88.2prp was engineered whereby four amino acid residues critical for plasminogen binding were converted to alanine codons in the GAS genome sequence. The mutated residues were reverse complemented to the wild-type sequence to construct GAS strain NS88.2prpRC. In comparison to NS88.2 and NS88.2prpRC, the NS88.2prp mutant exhibited significantly reduced ability to bind human plasminogen and accumulate cell surface plasmin activity during growth in human plasma. Utilizing a humanized plasminogen mouse model of invasive infection, we demonstrate that the capacity to bind plasminogen and accumulate surface plasmin activity plays an essential role in GAS virulence.
    • The M1 protein of Streptococcus pyogenes triggers an innate uptake mechanism into polarized human endothelial cells.

      Ochel, Anja; Rohde, Manfred; Chhatwal, Gursharan S; Talay, Susanne R; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweíg, Germany. (2014)
      Serotype M1 Streptococcus pyogenes is a major human pathogen associated with severe invasive diseases causing high morbidity and mortality. In a substantial number of cases, invasive disease develops in previously healthy individuals with no obvious port of entry. This has led to the hypothesis that the source of streptococci in these cases is a transient bacteraemia. This study focuses on the analysis of interaction of tissue-invasive serotype M1 S. pyogenes with human endothelial cells (EC) of the vascular system. We identify the M1 surface protein of S. pyogenes as the EC invasin which is recognised by polarized human blood EC, thereby triggering rapid, phagocytosis-like uptake of streptococci into polarized EC layers. Upon internalization, the M1 S. pyogenes serotype is incorporated into phagosomes which traffic via the endosomal/lysosomal pathway. However, some of the streptococci successfully evade this innate killing process and hereby mediate their escape into the cytoplasm of the host cell. The results of this study demonstrate that blood EC possess an efficient uptake mechanism for serotype M1 S. pyogenes. Despite efficient phagocytosis, streptococcal survival within EC constitutes one potential mechanism which favours intracellular persistence and thus facilitates continuous infection and dissemination from the primary side of infection into deep tissue.
    • Microevolution of group A streptococci in vivo: capturing regulatory networks engaged in sociomicrobiology, niche adaptation, and hypervirulence.

      Aziz, Ramy K; Kansal, Rita; Aronow, Bruce J; Taylor, William L; Rowe, Sarah L; Kubal, Michael; Chhatwal, Gursharan S; Walker, Mark J; Kotb, Malak; Research Services, Veterans Affairs Medical Center, Memphis, Tennessee, United States of America. ramy.aziz@salmonella.org (2010)
      The onset of infection and the switch from primary to secondary niches are dramatic environmental changes that not only alter bacterial transcriptional programs, but also perturb their sociomicrobiology, often driving minor subpopulations with mutant phenotypes to prevail in specific niches. Having previously reported that M1T1 Streptococcus pyogenes become hypervirulent in mice due to selection of mutants in the covRS regulatory genes, we set out to dissect the impact of these mutations in vitro and in vivo from the impact of other adaptive events. Using a murine subcutaneous chamber model to sample the bacteria prior to selection or expansion of mutants, we compared gene expression dynamics of wild type (WT) and previously isolated animal-passaged (AP) covS mutant bacteria both in vitro and in vivo, and we found extensive transcriptional alterations of pathoadaptive and metabolic gene sets associated with invasion, immune evasion, tissue-dissemination, and metabolic reprogramming. In contrast to the virulence-associated differences between WT and AP bacteria, Phenotype Microarray analysis showed minor in vitro phenotypic differences between the two isogenic variants. Additionally, our results reflect that WT bacteria's rapid host-adaptive transcriptional reprogramming was not sufficient for their survival, and they were outnumbered by hypervirulent covS mutants with SpeB(-)/Sda(high) phenotype, which survived up to 14 days in mice chambers. Our findings demonstrate the engagement of unique regulatory modules in niche adaptation, implicate a critical role for bacterial genetic heterogeneity that surpasses transcriptional in vivo adaptation, and portray the dynamics underlying the selection of hypervirulent covS mutants over their parental WT cells.
    • microscopy

      Rohde, Manfred (Elsevier, 2011)
    • Molecular Analysis of Group B Protective Surface Protein, a New Cell Surface Protective Antigen of Group B Streptococci

      Erdogan, Sezgin; Fagan, Peter K.; Talay, Susanne R.; Rohde, Manfred; Ferrieri, Patricia; Flores, Aurea E.; Guzmán, Carlos A.; Walker, Mark J.; Chhatwal, Gursharan S. (American Society for Microbiology, 2002-02)
    • Non-contiguous finished genome sequence and contextual data of the filamentous soil bacterium Ktedonobacter racemifer type strain (SOSP1-21).

      Chang, Yun-Juan; Land, Miriam; Hauser, Loren; Chertkov, Olga; Del Rio, Tijana Glavina; Nolan, Matt; Copeland, Alex; Tice, Hope; Cheng, Jan-Fang; Lucas, Susan; et al. (2011-10-15)
      Ktedonobacter racemifer corrig. Cavaletti et al. 2007 is the type species of the genus Ktedonobacter, which in turn is the type genus of the family Ktedonobacteraceae, the type family of the order Ktedonobacterales within the class Ktedonobacteria in the phylum 'Chloroflexi'. Although K. racemifer shares some morphological features with the actinobacteria, it is of special interest because it was the first cultivated representative of a deep branching unclassified lineage of otherwise uncultivated environmental phylotypes tentatively located within the phylum 'Chloroflexi'. The aerobic, filamentous, non-motile, spore-forming Gram-positive heterotroph was isolated from soil in Italy. The 13,661,586 bp long non-contiguous finished genome consists of ten contigs and is the first reported genome sequence from a member of the class Ktedonobacteria. With its 11,453 protein-coding and 87 RNA genes, it is the largest prokaryotic genome reported so far. It comprises a large number of over-represented COGs, particularly genes associated with transposons, causing the genetic redundancy within the genome being considerably larger than expected by chance. This work is a part of the Genomic Encyclopedia of Bacteria and Archaea project.
    • Non-contiguous finished genome sequence of Aminomonas paucivorans type strain (GLU-3).

      Pitluck, Sam; Yasawong, Montri; Held, Brittany; Lapidus, Alla; Nolan, Matt; Copeland, Alex; Lucas, Susan; Del Rio, Tijana Glavina; Tice, Hope; Cheng, Jan-Fang; et al. (2010)
      Aminomonas paucivorans Baena et al. 1999 is the type species of the genus Aminomonas, which belongs to the family Synergistaceae. The species is of interest because it is an asaccharolytic chemoorganotrophic bacterium which ferments quite a number of amino acids. This is the first finished genome sequence (with one gap in a rDNA region) of a member of the genus Aminomonas and the third sequence from the family Synergistaceae. The 2,630,120 bp long genome with its 2,433 protein-coding and 61 RNA genes is a part of the GenomicEncyclopedia ofBacteria andArchaea project.
    • Non-contiguous finished genome sequence of Bacteroides coprosuis type strain (PC139).

      Land, Miriam; Held, Brittany; Gronow, Sabine; Abt, Birte; Lucas, Susan; Del Rio, Tijana Glavina; Nolan, Matt; Tice, Hope; Cheng, Jan-Fang; Pitluck, Sam; et al. (2011-04-29)
      Bacteroides coprosuis Whitehead et al. 2005 belongs to the genus Bacteroides, which is a member of the family Bacteroidaceae. Members of the genus Bacteroides in general are known as beneficial protectors of animal guts against pathogenic microorganisms, and as contributors to the degradation of complex molecules such as polysaccharides. B. coprosuis itself was isolated from a manure storage pit of a swine facility, but has not yet been found in an animal host. The species is of interest solely because of its isolated phylogenetic location. The genome of B. coprosuis is already the 5(th) sequenced type strain genome from the genus Bacteroides. The 2,991,798 bp long genome with its 2,461 protein-coding and 78 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.
    • Non-contiguous finished genome sequence of the opportunistic oral pathogen Prevotella multisaccharivorax type strain (PPPA20).

      Pati, Amrita; Gronow, Sabine; Lu, Megan; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; et al. (2011-10-15)
      Prevotella multisaccharivorax Sakamoto et al. 2005 is a species of the large genus Prevotella, which belongs to the family Prevotellaceae. The species is of medical interest because its members are able to cause diseases in the human oral cavity such as periodontitis, root caries and others. Although 77 Prevotella genomes have already been sequenced or are targeted for sequencing, this is only the second completed genome sequence of a type strain of a species within the genus Prevotella to be published. The 3,388,644 bp long genome is assembled in three non-contiguous contigs, harbors 2,876 protein-coding and 75 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.
    • A novel intranasal mouse model for mucosal colonization by Streptococcus suis serotype 2.

      Seitz, Maren; Beineke, Andreas; Seele, Jana; Fulde, Marcus; Valentin-Weigand, Peter; Baums, Christoph Georg; 1Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Germany. (2012-09)
      Streptococcus suis causes meningitis and various other diseases in pigs and humans. Healthy piglets carrying virulent Streptococcus suis strains on their mucosal surfaces are epidemiologically very important. The objective of this study was to establish an intranasal Streptococcus suis mouse model for invasion and colonization of the respiratory tract. CD1 mice were infected intranasally with a highly virulent Streptococcus suis serotype 2 strain under different conditions. Clinical, histological and bacteriological screenings revealed that invasion of host tissue occurred in the majority of mice only after predisposition with 12.5 µl 1 % acetic acid per nostril. Severe fibrinosuppurative or purulent necrotizing pneumonia associated with Streptococcus suis was a common manifestation. Furthermore, a novel model to study nasopharyngeal colonization was established by reducing the volume of 1 % acetic acid per nostril to 5 µl prior to Streptococcus suis application. This model mimics asymptomatic carriage in swine, as all mice carried Streptococcus suis on their respiratory mucosa at 7 days post-infection (p.i.) in moderate to high numbers without the development of pneumonia or any other invasive Streptococcus suis disease. This intranasal Streptococcus suis model was applied to investigate the function of suilysin (SLY) in colonization. Although an isogenic SLY mutant was isolated from the upper respiratory tract at a lower recovery rate than its wild-type parental strain at 14 days p.i., the differences were not significant and did not indicate severe attenuation in colonization. In conclusion, this work describes to the best of our knowledge the first intranasal mouse model to study colonization of the respiratory tract by a highly virulent Streptococcus suis pathotype.
    • A novel role for the transcription factor HIF-1α in the formation of mast cell extracellular traps.

      Branitzki-Heinemann, Katja; Okumura, Cheryl Y; Völlger, Lena; Kawakami, Yuko; Kawakami, Toshiaki; Naim, Hassan Y; Nizet, Victor; Von Köckritz-Blickwede, Maren; Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA. (2012-08-15)
      MCs (mast cells) are critical components of the host innate immune defence against bacterial pathogens, providing a variety of intra- and extra-cellular antimicrobial functions. In the present study we show, for the first time, that the transcriptional regulator HIF-1α (hypoxia-inducible factor-1α) mediates the extracellular antimicrobial activity of human and murine MCs by increasing the formation of MCETs (MC extracellular traps).
    • On the origin of the electrostatic surface potential of Aspergillus niger spores in acidic environments.

      Wargenau, Andreas; Fleissner, André; Bolten, Christoph Josef; Rohde, Manfred; Kampen, Ingo; Kwade, Arno; Institut für Partikeltechnik, Technische Universität Braunschweig, Volkmaroder Straße 5, D-38104 Braunschweig, Germany. wargenau@a-wargenau.de (2011-12)
      The electrostatic surface potential of fungal spores is generally regarded as potentially influencing spore aggregation and pellet formation in submerged cultures of filamentous fungi. Spores of Aspergillus niger are typically characterized by negative zeta potentials over a wide range of pH values. In this study, this particular behavior is ascribed to the presence of an extensive melanin coating. It is proposed on the basis of zeta potential and pigment extraction experiments that this outermost layer affects the pH-dependent surface potential in two manners: (i) by the addition of negative charges to the spore surface and (ii) by the pH-dependent release of melanin pigment. Chemical analyses revealed that deprotonation of melanin-bound carboxyl groups is most probably responsible for pigment release under acidic conditions. These findings were incorporated into a simple model which has the ability to qualitatively explain the results of zeta potential experiments and, moreover, to provide the basis for quantitative investigations on the role of electrostatics in spore aggregation.
    • An optimized in vitro blood-brain barrier model reveals bidirectional transmigration of African trypanosome strains.

      Untucht, Christopher; Rasch, Janine; Fuchs, Elena; Rohde, Manfred; Bergmann, Simone; Steinert, Michael (2011-10)
      The transmigration of African trypanosomes across the human blood-brain barrier (BBB) is the critical step during the course of human African trypanosomiasis. The parasites Trypanosoma brucei gambiense and T. b. rhodesiense are transmitted to humans during the bite of tsetse flies. Trypanosomes multiply within the bloodstream and finally invade the central nervous system (CNS), which leads to the death of untreated patients. This project focused on the mechanisms of trypanosomal traversal across the BBB. In order to establish a suitable in vitro BBB model for parasite transmigration, different human cell lines were used, including ECV304, HBMEC and HUVEC, as well as C6 rat astrocytes. Validation of the BBB models with Escherichia coli HB101 and E. coli K1 revealed that a combination of ECV304 cells seeded on Matrigel as a semi-synthetic basement membrane and C6 astrocytes resulted in an optimal BBB model system. The BBB model showed selective permeability for the pathogenic E. coli K1 strain, and African trypanosomes were able to traverse the optimized ECV304-C6 BBB efficiently. Furthermore, coincubation indicated that paracellular macrophage transmigration does not facilitate trypanosomal BBB traversal. An inverse assembly of the BBB model demonstrated that trypanosomes were also able to transmigrate the optimized ECV304-C6 BBB backwards, indicating the relevance of the CNS as a possible reservoir of a relapsing parasitaemia.
    • P159 is a proteolytically processed, surface adhesin of Mycoplasma hyopneumoniae: defined domains of P159 bind heparin and promote adherence to eukaryote cells.

      Burnett, Tracey A; Dinkla, Katrin; Rohde, Manfred; Chhatwal, Gursharan S; Uphoff, Cord; Srivastava, Mukesh; Cordwell, Stuart J; Geary, Steven; Liao, Xiaofen; Minion, F Chris; et al. (2006-05-01)
      Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, colonizes the respiratory cilia of affected swine causing significant economic losses to swine production worldwide. Heparin is known to inhibit adherence of M. hyopneumoniae to porcine respiratory epithelial cilia. M. hyopneumoniae cells bind heparin but the identity of the heparin-binding proteins is limited. Proteomic analysis of M. hyopneumoniae lysates identified 27 kDa (P27), 110 kDa (P110) and 52 kDa (P52) proteins representing different regions of a 159 kDa (P159) protein derived from mhp494. These cleavage fragments were surface located and present at all growth stages. Following purification of four recombinant proteins spanning P159 (F1P159, F2P159, F3P159 and F4P159), only F3P159 and F4P159 bound heparin in a dose-dependent manner (K(d) values 142.37 +/- 22.01 nM; 75.37 +/- 7.34 nM respectively). Scanning electron microscopic studies showed M. hyopneumoniae bound intimately to porcine kidney epithelial-like cells (PK15 cells) but these processes were inhibited by excess heparin and F4P159. Similarly, latex beads coated with F2P159 and F4P159 adhered to and entered PK15 cells, but heparin, F2P159 and F4P159 was inhibitory. These findings indicate that P159 is a post-translationally cleaved, glycosaminoglycan-binding adhesin of M. hyopneumoniae.
    • PavA of Streptococcus pneumoniae Modulates Adherence, Invasion, and Meningeal Inflammation

      Pracht, Daniela; Elm, Christine; Gerber, Joachim; Bergmann, Simone; Rohde, Manfred; Seiler, Marleen; Kim, Kwang S.; Jenkinson, Howard F.; Nau, Roland; Hammerschmidt, Sven (American Society for Microbiology, 2005-05)
    • Permanent draft genome sequence of Dethiosulfovibrio peptidovorans type strain (SEBR 4207).

      Labutti, Kurt; Mayilraj, Shanmugam; Clum, Alicia; Lucas, Susan; Glavina Del Rio, Tijana; Nolan, Matt; Tice, Hope; Cheng, Jan-Fang; Pitluck, Sam; Liolios, Konstantinos; et al. (2010)
      Dethiosulfovibrio peptidovorans Magot et al. 1997 is the type species of the genus Dethiosulfovibrio of the family Synergistaceae in the recently created phylum Synergistetes. The strictly anaerobic, vibriod, thiosulfate-reducing bacterium utilizes peptides and amino acids, but neither sugars nor fatty acids. It was isolated from an offshore oil well where it was been reported to be involved in pitting corrosion of mild steel. Initially, this bacterium was described as a distant relative of the genus Thermoanaerobacter, but was not assigned to a genus, it was subsequently placed into the novel phylum Synergistetes. A large number of repeats in the genome sequence prevented an economically justifiable closure of the last gaps. This is only the third published genome from a member of the phylum Synergistetes. The 2,576,359 bp long genome consists of three contigs with 2,458 protein-coding and 59 RNA genes and is part of the Genomic Encyclopedia of Bacteria and Archaea project.
    • Permanent draft genome sequence of the gliding predator Saprospira grandis strain Sa g1 (= HR1).

      Mavromatis, Konstantinos; Chertkov, Olga; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Tice, Hope; Del Rio, Tijana Glavina; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; et al. (2012-05-25)
      Saprospira grandis Gross 1911 is a member of the Saprospiraceae, a family in the class 'Sphingobacteria' that remains poorly characterized at the genomic level. The species is known for preying on other marine bacteria via 'ixotrophy'. S. grandis strain Sa g1 was isolated from decaying crab carapace in France and was selected for genome sequencing because of its isolated location in the tree of life. Only one type strain genome has been published so far from the Saprospiraceae, while the sequence of strain Sa g1 represents the second genome to be published from a non-type strain of S. grandis. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 4,495,250 bp long Improved-High-Quality draft of the genome with its 3,536 protein-coding and 62 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.