• Silvanigrella aquatica gen. nov., sp. nov., isolated from a freshwater lake, description of Silvanigrellaceae fam. nov. and Silvanigrellales ord. nov., reclassification of the order Bdellovibrionales in the class Oligoflexia, reclassification of the families Bacteriovoracaceae and Halobacteriovoraceae in the new order Bacteriovoracales ord. nov., and reclassification of the family Pseudobacteriovoracaceae in the order Oligoflexales.

      Hahn, Martin W; Schmidt, Johanna; Koll, Ulrike; Rohde, M; Verbarg, Susanne; Pitt, Alexandra; Nakai, Ryosuke; Naganuma, Takeshi; Lang, Elke; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017-08)
      The unusual chemo-organoheterotrophic proteobacterial strain MWH-Nonnen-W8redT was isolated from a lake located in the Black Forest (Schwarzwald), Germany, by using the filtration-acclimatization method. Phylogenetic analyses based on the 16S rRNA gene sequence of the strain could not provide clear hints on classification of the strain in one of the current classes of the phylum Proteobacteria. Whole-genome sequencing resulted in a genome size of 3.5 Mbp and revealed a quite low DNA G+C content of 32.6 mol%. In-depth phylogenetic analyses based on alignments of 74 protein sequences of a phylogenetically broad range of taxa suggested assignment of the strain to a new order of the class Oligoflexia. These analyses also suggested that the order Bdellovibrionales should be transferred from the class Deltaproteobacteria to the class Oligoflexia, that this order should be split into two orders, and that the family Pseudobacteriovoracaceae should be transferred from the order Bdellovibrionales to the order Oligoflexales. We propose to establish for strain MWH-Nonnen-W8redT (=DSM 23856T=CCUG 58639T) the novel species and genus Silvanigrella aquatica gen. nov., sp. nov. to be placed in the new family Silvanigrellaceae fam. nov. of the new order Silvanigrellales ord. nov.
    • Single cell analysis applied to antibody fragment production with Bacillus megaterium: development of advanced physiology and bioprocess state estimation tools

      David, Florian; Berger, Antje; Hänsch, Robert; Rohde, Manfred; Franco-Lara, Ezequiel (2011-04-15)
      Abstract Background Single cell analysis for bioprocess monitoring is an important tool to gain deeper insights into particular cell behavior and population dynamics of production processes and can be very useful for discrimination of the real bottleneck between product biosynthesis and secretion, respectively. Results Here different dyes for viability estimation considering membrane potential (DiOC2(3), DiBAC4(3), DiOC6(3)) and cell integrity (DiBAC4(3)/PI, Syto9/PI) were successfully evaluated for Bacillus megaterium cell characterization. It was possible to establish an appropriate assay to measure the production intensities of single cells revealing certain product secretion dynamics. Methods were tested regarding their sensitivity by evaluating fluorescence surface density and fluorescent specific concentration in relation to the electronic cell volume. The assays established were applied at different stages of a bioprocess where the antibody fragment D1.3 scFv production and secretion by B. megaterium was studied. Conclusions It was possible to distinguish between live, metabolic active, depolarized, dormant, and dead cells and to discriminate between high and low productive cells. The methods were shown to be suitable tools for process monitoring at single cell level allowing a better process understanding, increasing robustness and forming a firm basis for physiology-based analysis and optimization with the general application for bioprocess development.
    • Standard susceptibility testing overlooks potent azithromycin activity and cationic peptide synergy against MDR Stenotrophomonas maltophilia.

      Kumaraswamy, Monika; Lin, Leo; Olson, Joshua; Sun, Ching-Fang; Nonejuie, Poochit; Corriden, Ross; Döhrmann, Simon; Ali, Syed Raza; Amaro, Deirdre; Rohde, M; et al. (2016-05)
      The Gram-negative bacillus Stenotrophomonas maltophilia (SM) is an emerging MDR opportunistic pathogen. Recent studies identify a potentially relevant activity of azithromycin against Gram-negative bacteria overlooked in standard bacteriological testing. We investigated azithromycin activity against SM in testing conditions incorporating mammalian tissue culture medium and host defence factors.
    • Stieleria varia sp. nov., isolated from wood particles in the Baltic Sea, constitutes a novel species in the family Pirellulaceae within the phylum Planctomycetes.

      Surup, Frank; Wiegand, Sandra; Boedeker, Christian; Heuer, Anja; Peeters, Stijn H; Jogler, Mareike; Jetten, Mike S M; Rohde, Manfred; Jogler, Christian; Kallscheuer, Nicolai; et al. (Springer, 2020-08-14)
      Species belonging to the bacterial phylum Planctomycetes are ubiquitous members of the microbial communities in aquatic environments and are frequently isolated from various biotic and abiotic surfaces in marine and limnic water bodies. Planctomycetes have large genomes of up to 12.4 Mb, follow complex lifestyles and display an uncommon cell biology; features which motivate the investigation of members of this phylum in greater detail. As a contribution to the current collection of axenic cultures of Planctomycetes, we here describe strain Pla52T isolated from wood particles in the Baltic Sea. Phylogenetic analysis places the strain in the family Pirellulaceae and suggests two species of the recently described genus Stieleria as current closest neighbours. Strain Pla52nT shows typical features of members of the class Planctomycetia, including division by polar budding and the presence of crateriform structures. Colonies of strain Pla52nT have a light orange colour, which is an unusual pigmentation compared to the majority of members in the phylum, which show either a pink to red pigmentation or entirely lack pigmentation. Optimal growth of strain Pla52nT at 33 °C and pH 7.5 indicates a mesophilic (i.e. with optimal growth between 20 and 45 °C) and neutrophilic growth profile. The strain is an aerobic heterotroph with motile daughter cells. Its genome has a size of 9.6 Mb and a G + C content of 56.0%. Polyphasic analyses justify delineation of the strain from described species within the genus Stieleria. Therefore, we conclude that strain Pla52nT = LMG 29463T = VKM B-3447T should be classified as the type strain of a novel species, for which we propose the name Stieleria varia sp. nov.
    • Still Something to Discover: Novel Insights into Phage Diversity and Taxonomy.

      Korf, Imke H E; Meier-Kolthoff, Jan P; Adriaenssens, Evelien M; Kropinski, Andrew M; Nimtz, Manfred; Rohde, Manfred; van Raaij, Mark J; Wittmann, Johannes; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (MDPI, 2019-05-17)
      The aim of this study was to gain further insight into the diversity of Escherichia coli phagesfollowed by enhanced work on taxonomic issues in that field. Therefore, we present the genomiccharacterization and taxonomic classification of 50 bacteriophages against E. coli isolated fromvarious sources, such as manure or sewage. All phages were examined for their host range on a setof different E. coli strains, originating, e.g., from human diagnostic laboratories or poultry farms.Transmission electron microscopy revealed a diversity of morphotypes (70% Myo-, 22% Sipho-, and8% Podoviruses), and genome sequencing resulted in genomes sizes from ~44 to ~370 kb.Annotation and comparison with databases showed similarities in particular to T4- and T5-likephages, but also to less-known groups. Though various phages against E. coli are already describedin literature and databases, we still isolated phages that showed no or only few similarities to otherphages, namely phages Goslar, PTXU04, and KWBSE43-6. Genome-based phylogeny andclassification of the newly isolated phages using VICTOR resulted in the proposal of new generaand led to an enhanced taxonomic classification of E. coli phages.
    • Streptococcus equi subsp. zooepidemicus Invades and Survives in Epithelial Cells.

      Skive, Bolette; Rohde, M; Molinari, Gabriella; Braunstein, Thomas Hartig; Bojesen, Anders M; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr.7, 38124 Braunschweig, Germany. (2017)
      Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is an opportunistic pathogen of several species including humans. S. zooepidemicus is found on mucus membranes of healthy horses, but can cause acute and chronic endometritis. Recently S. zooepidemicus was found able to reside in the endometrium for prolonged periods of time. Thus, we hypothesized that an intracellular phase may be part of the S. zooepidemicus pathogenesis and investigated if S. zooepidemicus was able to invade and survive inside epithelial cells. HEp-2 and HeLa cell lines were co-cultured with two S. zooepidemicus strains (1-4a and S31A1) both originating from the uterus of mares suffering from endometritis. Cells were fixed at different time points during the 23 h infection assay and field emission scanning electron microscopy (FESEM) was used to characterize adhesion and invasion mechanisms. The FESEM images showed three morphologically different types of invasion for both bacterial strains. The main port of entry was through large invaginations in the epithelial cell membrane. Pili-like bacterial appendages were observed when the S. zooepidemicus cells were in close proximity to the epithelial cells indicating that attachment and invasion were active processes. Adherent and intracellular S. zooepidemicus, and bacteria in association with lysosomes was determined by immunofluorescence staining techniques and fluorescence microscopy. Quantification of intracellular bacteria was determined in penicillin protection assays. Both S. zooepidemicus strains investigated were able to invade epithelial cells although at different magnitudes. The immunofluorescence data showed significantly higher adhesion and invasion rates for strain 1-4a when compared to strain S31A1. S. zooepidemicus was able to survive intracellularly, but the survival rate decreased over time in the cell culture system. Phagosome-like compartments containing S. zooepidemicus at some stages fused with lysosomes to form a phagolysosome. The results indicate that an intracellular phase may be one way S. zooepidemicus survives in the host, and could in part explain how S. zooepidemicus can cause recurrent/persistent infections. Future studies should reveal the ability of S. zooepidemicus to internalize and survive in primary equine endometrial cells and during in vivo conditions.
    • Streptococcus pyogenes adhesion and colonization.

      Brouwer, Stephan; Barnett, Timothy C; Rivera-Hernandez, Tania; Rohde, M; Walker, Mark J; Helmholtz Centre for infection research, Inhoffenstr. 7,38124 Braunschweig, Germany. (2016-06-17)
      Streptococcus pyogenes (group A Streptococcus, GAS) is a human-adapted pathogen responsible for a wide spectrum of disease. GAS can cause relatively mild illnesses, such as strep throat or impetigo, and less frequent but severe life-threatening diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome. GAS is an important public health problem causing significant morbidity and mortality worldwide. The main route of GAS transmission between humans is through close or direct physical contact, and particularly via respiratory droplets. The upper respiratory tract and skin are major reservoirs for GAS infections. The ability of GAS to establish an infection in the new host at these anatomical sites primarily results from two distinct physiological processes, namely bacterial adhesion and colonization. These fundamental aspects of pathogenesis rely upon a variety of GAS virulence factors, which are usually under strict transcriptional regulation. Considerable progress has been made in better understanding these initial infection steps. This review summarizes our current knowledge of the molecular mechanisms of GAS adhesion and colonization.
    • Sulfate-Reducing Bacteria That Produce Exopolymers Thrive in the Calcifying Zone of a Hypersaline Cyanobacterial Mat.

      Spring, Stefan; Sorokin, Dimitry Y; Verbarg, Susanne; Rohde, M; Woyke, Tanja; Kyrpides, Nikos C; HZI, Helmholtz Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (Frontiers, 2019-01-01)
      Calcifying microbial mats in hypersaline environments are important model systems for the study of the earliest ecosystems on Earth that started to appear more than three billion years ago and have been preserved in the fossil record as laminated lithified structures known as stromatolites. It is believed that sulfate-reducing bacteria play a pivotal role in the lithification process by increasing the saturation index of calcium minerals within the mat. Strain L21-Syr-ABT was isolated from anoxic samples of a several centimeters-thick microbialite-forming cyanobacterial mat of a hypersaline lake on the Kiritimati Atoll (Kiribati, Central Pacific). The novel isolate was assigned to the family Desulfovibrionaceae within the Deltaproteobacteria. Available 16S rRNA-based population surveys obtained from discrete layers of the mat indicate that the occurrence of a species-level clade represented by strain L21-Syr-ABT is restricted to a specific layer of the suboxic zone, which is characterized by the presence of aragonitic spherulites. To elucidate a possible function of this sulfate-reducing bacterium in the mineral formation within the mat a comprehensive phenotypic characterization was combined with the results of a comparative genome analysis. Among the determined traits of strain L21-Syr-ABT, several features were identified that could play a role in the precipitation of calcium carbonate: (i) the potential deacetylation of polysaccharides and consumption of substrates such as lactate and sulfate could mobilize free calcium; (ii) under conditions that favor the utilization of formate and hydrogen, the alkalinity engine within the mat is stimulated, thereby increasing the availability of carbonate; (iii) the production of extracellular polysaccharides could provide nucleation sites for calcium mineralization. In addition, our data suggest the proposal of the novel species and genus Desulfohalovibrio reitneri represented by the type strain L21-Syr-ABT (=DSM 26903T = JCM 18662T).
    • Targeting bioenergetics is key to counteracting the drug-tolerant state of biofilm-grown bacteria.

      Donnert, Monique; Elsheikh, Sarah; Arce-Rodriguez, Alejandro; Pawar, Vinay; Braubach, Peter; Jonigk, Danny; Haverich, Axel; Weiss, Siegfried; Müsken, Mathias; Häussler, Susanne; et al. (PLOS, 2020-12-22)
      Embedded in an extracellular matrix, biofilm-residing bacteria are protected from diverse physicochemical insults. In accordance, in the human host the general recalcitrance of biofilm-grown bacteria hinders successful eradication of chronic, biofilm-associated infections. In this study, we demonstrate that upon addition of promethazine, an FDA approved drug, antibiotic tolerance of in vitro biofilm-grown bacteria can be abolished. We show that following the addition of promethazine, diverse antibiotics are capable of efficiently killing biofilm-residing cells at minimal inhibitory concentrations. Synergistic effects could also be observed in a murine in vivo model system. PMZ was shown to increase membrane potential and interfere with bacterial respiration. Of note, antibiotic killing activity was elevated when PMZ was added to cells grown under environmental conditions that induce low intracellular proton levels. Our results imply that biofilm-grown bacteria avoid antibiotic killing and become tolerant by counteracting intracellular alkalization through the adaptation of metabolic and transport functions. Abrogation of antibiotic tolerance by interfering with the cell's bioenergetics promises to pave the way for successful eradication of biofilm-associated infections. Repurposing promethazine as a biofilm-sensitizing drug has the potential to accelerate the introduction of new treatments for recalcitrant, biofilm-associated infections into the clinic.
    • TatBC-Independent TatA/Tat Substrate Interactions Contribute to Transport Efficiency.

      Taubert, Johannes; Hou, Bo; Risselada, H Jelger; Mehner, Denise; Lünsdorf, Heinrich; Grubmüller, Helmut; Brüser, Thomas (2015)
      The Tat system can transport folded, signal peptide-containing proteins (Tat substrates) across energized membranes of prokaryotes and plant plastids. A twin-arginine motif in the signal peptide of Tat substrates is recognized by TatC-containing complexes, and TatA permits the membrane passage. Often, as in the model Tat systems of Escherichia coli and plant plastids, a third component - TatB - is involved that resembles TatA but has a higher affinity to TatC. It is not known why most TatA dissociates from TatBC complexes in vivo and distributes more evenly in the membrane. Here we show a TatBC-independent substrate-binding to TatA from Escherichia coli, and we provide evidence that this binding enhances Tat transport. First hints came from in vivo cross-linking data, which could be confirmed by affinity co-purification of TatA with the natural Tat substrates HiPIP and NrfC. Two positions on the surface of HiPIP could be identified that are important for the TatA interaction and transport efficiency, indicating physiological relevance of the interaction. Distributed TatA thus may serve to accompany membrane-interacting Tat substrates to the few TatBC spots in the cells.
    • Taxonomic analyses of members of the Streptomyces cinnabarinus cluster, description of Streptomyces cinnabarigriseus sp. nov. and Streptomyces davaonensis sp. nov.

      Landwehr, Wiebke; Kämpfer, Peter; Glaeser, Stefanie P; Rückert, Christian; Kalinowski, Jörn; Blom, Jochen; Goesmann, Alexander; Mack, Matthias; Schumann, Peter; Atasayar, Ewelina; et al. (2017-12-11)
      Roseoflavin is the only known riboflavin (vitamin B2) analog with antibiotic properties. It is actively taken up by many micro-organisms and targets flavinmononucleotide riboswitches and flavoproteins. It is described as the product of the tentatively named 'Streptomyces davawensis' JCM 4913. Taxonomic analysis of this strain with a polyphasic approach showed that it is very closely related to Streptomyces cinnabarinus (DSM 40467). The two Streptomyces isolates were obtained from different geographical locations (the Philippines and the Kamchatka Peninsula, respectively), their genomes have been sequenced and the question was whether or not the two isolates were representatives of the same species. As we also worked with another isolate of Streptomyces cinnabarinus JS 360, the producer of the cinnabaramides, we wanted to clarify the taxonomic position of the three isolates by using a polyphasic approach. After analysis of the 16S rRNA gene sequence, we found in total 23 species of the genus Streptomyces that showed a similarity higher than 98.5 % to the three strains. We showed that 'S. davawensis' JCM 4913 and S. cinnabarinus DSM 40467 were very closely related but belong to two different species. Hence, we validate 'S. davawensis' as Streptomyces davaonensis sp. nov. with the type strain JCM 4913T (=DSM 101723T). In addition, the cinnabaramide producer can be clearly differentiated from S. davaonensis and this isolate is described as Streptomyces cinnabarigriseus sp. nov. with strain JS360T (=NCCB 100590T=DSM 101724T) as the type strain.
    • Terricaulis silvestris gen. Nov., sp. nov., a novel prosthecate, budding member of the family caulobacteraceae isolated from forest soil

      Vieira, Selma; Pascual, Javier; Boedeker, Christian; Geppert, Alicia; Riedel, Thomas; Rohde, Manfred; Overmann, Jörg; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (Microbiology Society, 2020-08-07)
      The family Caulobacteraceae comprises prosthecate bacteria with a dimorphic cell cycle and also non-prosthecate bacteria. Cells of all described species divide by binary fission. Strain 0127_4T was isolated from forest soil in Baden Württemberg (Germany) and determined to be the first representative of the family Caulobacteraceae which divided by budding. Cells of strain 0127_4T were Gram-negative, rod-shaped, prosthecate, motile by means of a polar flagellum, non-spore-forming and non-capsulated. The strain formed small white colonies and grew aerobically and chemo-organotrophically utilizing organic acids, amino acids and proteinaceous substrates. 16S rRNA gene sequence analysis indicated that this bacterium was related to Aquidulcibacter paucihalophilus TH1-2T and Asprobacter aquaticus DRW22-8T with 91.3 and 89.7% sequence similarity, respectively. Four unidentified glycolipids were detected as the major polar lipids and, unlike all described members of the family Caulobacteraceae, phosphatidylglycerol was absent. The major fatty acids were summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), summed feature 9 (iso-C17 : 1ω9c/C16 : 0 10-methyl), C16 : 0 and summed feature 3 (C16 : 1ω6c/C16 : 1ω7c). The major respiratory quinone was Q-10. The G+C content of the genomic DNA was 63.5 %. Based on the present taxonomic characterization, strain 0127_4T represents a novel species of a new genus, Terricaulis silvestris gen. nov., sp. nov. The type strain of Terricaulis silvestris is 0127_4T (=DSM 104635T=CECT 9243T).
    • Thalassoglobus polymorphus sp. nov., a novel Planctomycete isolated close to a public beach of Mallorca Island.

      Rivas-Marin, Elena; Wiegand, Sandra; Kallscheuer, Nicolai; Jogler, Mareike; Peeters, Stijn H; Heuer, Anja; Jetten, Mike S M; Boedeker, Christian; Rohde, Manfred; Devos, Damien P; et al. (Springer, 2020-06-24)
      Access to axenic cultures is crucial to extend the knowledge of the biology, lifestyle or metabolic capabilities of bacteria from different phyla. The phylum Planctomycetes is an excellent example since its members display an unusual cell biology and complex lifestyles. As a contribution to the current collection of axenic planctomycete cultures, here we describe strain Mal48T isolated from phytoplankton material sampled at the coast of S'Arenal close to Palma de Mallorca (Spain). The isolated strain shows optimal growth at pH 7.0-7.5 and 30 °C and exhibits typical features of Planctomycetes. Cells of the strain are spherical to pear-shaped, divide by polar budding with daughter cells showing the same shape as the mother cell, tend to aggregate, display a stalk and produce matrix or fimbriae. Strain Mal48T showed 95.8% 16S rRNA gene sequence similarity with the recently described Thalassoglobus neptunius KOR42T. The genome sequence of the novel isolate has a size of 6,357,355 bp with a G+C content of 50.3%. A total of 4874 protein-coding genes, 41 tRNA genes and 2 copies of the 16S rRNA gene are encoded in the genome. Based on phylogenetic, morphological and physiological analyses, we conclude that strain Mal48T (= DSM 100737T = LMG 29019T) should be classified as the type strain of a new species in the genus Thalassoglobus, for which the name Thalassoglobus polymorphus sp. nov. is proposed.
    • Three glycosylated serine-rich repeat proteins play a pivotal role in adhesion and colonization of the pioneer commensal bacterium, Streptococcus salivarius.

      Couvigny, Benoit; Lapaque, Nicolas; Rigottier-Gois, Lionel; Guillot, Alain; Chat, Sophie; Meylheuc, Thierry; Kulakauskas, Saulius; Rohde, M; Mistou, Michel-Yves; Renault, Pierre; et al. (Wiley-Blackwell, 2017-01-01)
      Bacterial adhesion is a critical step for colonization of the host. The pioneer colonizer and commensal bacterium of the human gastrointestinal tract, Streptococcus salivarius, has strong adhesive properties but the molecular determinants of this adhesion remain uncharacterized. Serine‐rich repeat (SRR) glycoproteins are a family of adhesins that fulfil an important role in adhesion. In general, Gram‐positive bacterial genomes have a unique SRR glycoprotein‐encoding gene. We demonstrate that S. salivarius expresses three large and glycosylated surface‐exposed proteins – SrpA, SrpB and SrpC – that show characteristics of SRR glycoproteins and are secreted through the accessory SecA2/Y2 system. Two glycosyltransferases – GtfE/F – encoded outside of the secA2/Y2 locus, unusually, perform the first step of the sequential glycosylation process, which is crucial for SRR activity. We show that SrpB and SrpC play complementary adhesive roles involved in several steps of the colonization process: auto‐aggregation, biofilm formation and adhesion to a variety of host epithelial cells and components. We also show that at least one of the S. salivarius SRR glycoproteins is important for colonization in mice. SrpA, SrpB and SrpC are the main factors underlying the multifaceted adhesion of S. salivarius and, therefore, play a major role in host colonization.
    • Three marine strains constitute the novel genus and species Crateriforma conspicua in the phylum Planctomycetes.

      Peeters, Stijn H; Wiegand, Sandra; Kallscheuer, Nicolai; Jogler, Mareike; Heuer, Anja; Jetten, Mike S M; Rast, Patrick; Boedeker, Christian; Rohde, Manfred; Jogler, Christian (2020-01-01)
      Planctomycetes is a ubiquitous phylum of mostly aquatic bacteria that have a complex lifestyle and an unusual cell biology. Here, we describe three strains of the same novel genus and species isolated from three different environments; from a red biofilm at a hydrothermal vent in the Mediterranean Sea, from sediment in a salt-water fish tank, and from the surface of algae at the coast of the Balearic island Mallorca. The three strains Mal65T (DSM 100706T = LMG 29792T, Pan14r (DSM 29351 = LMG 29012), and V7 (DSM 29812 = CECT 9853 = VKM B-3427) show typical characteristics of the Planctomycetaceae family, such as cell division by budding, crateriform structures and growth in aggregates or rosettes.  The strains are mesophilic, neutrophilic to alkaliphilic as well as chemoheterotrophic and exhibit doubling times between 12 and 35 h. Based on our phylogenetic analysis, the three strains represent a single novel species of a new genus, for which we propose the name Crateriforma conspicua gen. nov. sp. nov.
    • Three novel Rubripirellula species isolated from plastic particles submerged in the Baltic Sea and the estuary of the river Warnow in northern Germany.

      Kallscheuer, Nicolai; Jogler, Mareike; Wiegand, Sandra; Peeters, Stijn H; Heuer, Anja; Boedeker, Christian; Jetten, Mike S M; Rohde, Manfred; Jogler, Christian (2019-12-05)
      Planctomycetes are a unique and important phylum containing mostly aquatic bacteria, which are often associated with phototrophic surfaces. A complex lifestyle, their potential for the production of bioactive small molecules, their unusual cell biology and a large number of giant and hypothetical genes in their genomes make these microorganisms a fascinating topic for further research. Here, we characterise three novel planctomycetal strains isolated from polystyrene and polyethylene particles that were submerged in the German part of the Baltic Sea and the estuary of the river Warnow. All three strains showed typical planctomycetal traits such as division by polar budding and formation of rosettes. The isolated strains were mesophilic and neutrophilic chemoheterotrophs and reached generation times of 10-25 h during laboratory-scale cultivation. Taxonomically, the three strains belong to the genus Rubripirellula. Based on our analyses all three strains represent novel species, for which we propose the names Rubripirellula amarantea sp. nov., Rubripirellula tenax sp. nov. and Rubripirellula reticaptiva sp. nov. The here characterised strains Pla22T (DSM 102267T = LMG 29691T), Poly51T (DSM 103356T = VKM B-3438T) and Poly59T (DSM 103767T = LMG 29696T) are the respective type strains of these novel species. We also emend the description of the genus Rubripirellula.
    • Three Novel Species with Peptidoglycan Cell Walls form the New Genus Lacunisphaera gen. nov. in the Family Opitutaceae of the Verrucomicrobial Subdivision 4.

      Rast, Patrick; Glöckner, Ines; Boedeker, Christian; Jeske, Olga; Wiegand, Sandra; Reinhardt, Richard; Schumann, Peter; Rohde, M; Spring, Stefan; Glöckner, Frank O; et al. (2017)
      The cell wall of free-living bacteria consists of peptidoglycan (PG) and is critical for maintenance of shape as dissolved solutes cause osmotic pressure and challenge cell integrity. Surprisingly, the subdivision 4 of the phylum Verrucomicrobia appears to be exceptional in this respect. Organisms of this subdivision are described to be devoid of muramic or diaminopimelic acid (DAP), usually found as components of PG in bacterial cell walls. Here we describe three novel bacterial strains from a freshwater lake, IG15(T), IG16b(T), and IG31(T), belonging to a new genus in the subdivision 4 of Verrucomicrobia which we found to possess PG as part of their cell walls. Biochemical analysis revealed the presence of DAP not only in these novel strains, but also in Opitutus terrae PB90-1(T), the closest described relative of strains IG15(T), IG16b(T), and IG31(T). Furthermore, we found that nearly all genes necessary for peptidoglycan synthesis are present in genomes of subdivision 4 members, as well as in the complete genome sequence of strain IG16b(T). In addition, we isolated and visualized PG-sacculi for strain IG16b(T). Thus, our results challenge the concept of peptidoglycan-less free-living bacteria. Our polyphasic taxonomy approach places the novel strains in a new genus within the family Opitutaceae, for which the name Lacunisphaera gen. nov. is proposed. Strain designations for IG15(T), IG16b(T) and IG31(T) are Lacunisphaera parvula sp. nov. (=DSM 26814 = LMG 29468), L. limnophila sp. nov. (=DSM 26815 = LMG 29469) and L. anatis sp. nov. (=DSM 103142 = LMG 29578) respectively, with L. limnophila IG16b(T) being the type species of the genus.
    • Three Planctomycetes isolated from biotic surfaces in the Mediterranean Sea and the Pacific Ocean constitute the novel species Symmachiella dynata gen. nov., sp. nov. and Symmachiella macrocystis sp. nov.

      Salbreiter, Markus; Waqqas, Muhammad; Jogler, Mareike; Kallscheuer, Nicolai; Wiegand, Sandra; Peeters, Stijn H; Heuer, Anja; Jetten, Mike S M; Boedeker, Christian; Rast, Patrick; et al. (Springer, 2020-08-24)
      Planctomycetes is a phylum of environmentally important bacteria, which also receive significant attention due to their fascinating cell biology. Access to axenic Planctomycete cultures is crucial to study cell biological features within this phylum in further detail. In this study, we characterise three novel strains, Mal52T, Pan258 and CA54T, which were isolated close to the coasts of the islands Mallorca (Spain) and Panarea (Italy), and from Monterey Bay, CA, USA. The three isolates show optimal growth at temperatures between 22 and 24 °C and at pH 7.5, divide by polar budding, lack pigmentation and form strong aggregates in liquid culture. Analysis of five phylogenetic markers suggests that the strains constitute two novel species within a novel genus in the family Planctomycetaceae. The strains Mal52T (DSM 101177T = VKM B-3432T) and Pan258 were assigned to the species Symmachiella dynata gen nov., sp. nov., while strain CA54T (DSM 104301T = VKM B-3450T) forms a separate species of the same genus, for which we propose the name Symmachiella macrocystis sp. nov.
    • Toll-like Receptor 5 Activation by the CagY Repeat Domains of Helicobacter pylori.

      Tegtmeyer, Nicole; Neddermann, Matthias; Lind, Judith; Pachathundikandi, Suneesh Kumar; Sharafutdinov, Irshad; Gutiérrez-Escobar, Andrés Julián; Brönstrup, Mark; Tegge, Werner; Hong, Minsun; Rohde, Manfred; et al. (Cell Press, 2020-11-15)
      Helicobacter pylori (Hp) is an important human pathogen associated with gastric inflammation and neoplasia. It is commonly believed that this bacterium avoids major immune recognition by Toll-like receptors (TLRs) because of low intrinsic activity of its flagellin and lipopolysaccharides (LPS). In particular, TLR5 specifically detects flagellins in various bacterial pathogens, while Hp evolved mutations in flagellin to evade detection through TLR5. Cancerogenic Hp strains encode a type IV secretion system (T4SS). The T4SS core component and pilus-associated protein CagY, a large VirB10 ortholog, drives effector molecule translocation. Here, we identify CagY as a flagellin-independent TLR5 agonist. We detect five TLR5 interaction sites, promoting binding of CagY-positive Hp to TLR5-expressing cells, TLR5 stimulation, and intracellular signal transduction. Consequently, CagY constitutes a remarkable VirB10 member detected by TLR5, driving crucial innate immune responses by this human pathogen.
    • Treatment of biofilms in bacterial vaginosis by an amphoteric tenside pessary-clinical study and microbiota analysis.

      Gottschick, Cornelia; Deng, Zhi-Luo; Vital, Marius; Masur, Clarissa; Abels, Christoph; Pieper, Dietmar H; Rohde, Manfred; Mendling, Werner; Wagner-Döbler, Irene; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017-09-13)
      Bacterial vaginosis (BV) is the most common vaginal syndrome among women in their reproductive years. It is associated with an increased risk of acquiring sexually transmitted infections and complications like preterm labor. BV is characterized by a high recurrence rate for which biofilms frequently found on vaginal epithelial cells may be a reason.