Institut für Hygiene und Mikrobiologie

    Bacterial capsules


    Many invasive pathogens (pneumococci, meningococci, H. influenzae, E. coli K1) express polysaccharide capsules on their surfaces, which protect them against immune effector mechanisms. Bacteria expressing capsules containing sialic acid are the focus of our studies. These capsules may be immunogenic and used in vaccine formulations. With regard to serogroup B meningococci and E. coli K1, however, only an ineffective immune response is elicited after administration of plain polysaccharide. Our group has worked on phase variation of capsule expression, on the distribution and exchange of capsule synthesis genes among clonal lineages of meningococci, on the genetic basis of substrate specificity of polysialyltransferases, as well as on the modification of polysialic acid by O-acetylation. Our current focus is the detailed analysis of the population biology and function of O-acetyltransferases in serogroup W135 and Y meningococci, as well as in E. coli K1 (collaboration with Martina Mühlenhoff, Hannover).



    • Fiebig, T., Berti, F., Freiberger, F., Pinto, V., Claus, H., Romano, M. R., Proietti, D., Brogioni, B., Stummeyer, K., Berger, M., Vogel, U., Costantino, P., and Gerardy-Schahn, R. (2014) Functional expression of the capsule polymerase of Neisseria meningitidis serogroup X: a new perspective for vaccine development, Glycobiology 24, 150-8.


    • Romanow, A., Haselhorst, T., Stummeyer, K., Claus, H., Bethe, A., Mühlenhoff, M., Vogel, U., von Itzstein, M., and Gerardy-Schahn, R. (2013) Biochemical and biophysical characterization of the sialyl-/hexosyltransferase synthesizing the meningococcal serogroup W135 heteropolysaccharide capsule, The Journal of biological chemistry 288, 11718--11730.
    • Harrison, O. B., Claus, H., Jiang, Y., Bennett, J. S., Bratcher, H. B., Jolley, K. A., Corton, C., Care, R., Poolman, J. T., Zollinger, W. D., Frasch, C. E., Stephens, D. S., Feavers, I., Frosch, M., Parkhill, J., Vogel, U., Quail, M. A., Bentley, S. D., and Maiden, M. C. J. (2013) Description and nomenclature of Neisseria meningitidis capsule locus, Emerging infectious diseases 19, 566--573.


    • Schwerk, C., Papandreou, T., Schuhmann, D., Nickol, L., Borkowski, J., Steinmann, U., Quednau, N., Stump, C., Weiss, C., Berger, J., Wolburg, H., Claus, H., Vogel, U., Ishikawa, H., Tenenbaum, T., and Schroten, H. (2012) Polar invasion and translocation of Neisseria meningitidis and Streptococcus suis in a novel human model of the blood-cerebrospinal fluid barrier, PloS one 7, e30069.


    • Lâm, T. -T., Claus, H., Frosch, M., and Vogel, U. (2011) Sequence analysis of serotype-specific synthesis regions II of Haemophilus influenzae serotypes c and d: evidence for common ancestry of capsule synthesis in Pasteurellaceae and Neisseria meningitidis, Research in Microbiology 162, 483--487.
    • Lâm, T. -T., Elias, J., Frosch, M., Vogel, U., and Claus, H. (2011) New diagnostic PCR for Haemophilus influenzae serotype e based on the cap locus of strain ATCC 8142, International Journal of Medical Microbiology: IJMM 301, 176--179.


    • Claus, H., Matsunaga, W., and Vogel, U. (2010) Molecular discrimination between Neisseria meningitidis serogroups W-135 and Y based on the nucleotide recognition domain sequence of the capsule polymerases, Journal of Clinical Microbiology 48, 3459--3460.


    • Claus, H., Stummeyer, K., Batzilla, J., Mühlenhoff, M., and Vogel, U. (2009) Amino acid 310 determines the donor substrate specificity of serogroup W-135 and Y capsule polymerases of Neisseria meningitidis, Molecular Microbiology 71, 960--971.
    • Mordhorst, I. L., Claus, H., Ewers, C., Lappann, M., Schoen, C., Elias, J., Batzilla, J., Dobrindt, U., Wieler, L. H., Bergfeld, A. K., MĂźhlenhoff, M., and Vogel, U. (2009) O-acetyltransferase gene neuO is segregated according to phylogenetic background and contributes to environmental desiccation resistance in Escherichia coli K1, Environmental Microbiology 11, 3154--3165.
    • Bergfeld, A. K., Claus, H., Lorenzen, N. K., Spielmann, F., Vogel, U., and MĂźhlenhoff, M. (2009) The polysialic acid-specific O-acetyltransferase OatC from Neisseria meningitidis serogroup C evolved apart from other bacterial sialate O-acetyltransferases, The Journal of Biological Chemistry 284, 6--16.


    • Freiberger, F., Claus, H., GĂźnzel, A., Oltmann-Norden, I., Vionnet, J., MĂźhlenhoff, M., Vogel, U., Vann, W. F., Gerardy-Schahn, R., and Stummeyer, K. (2007) Biochemical characterization of a Neisseria meningitidis polysialyltransferase reveals novel functional motifs in bacterial sialyltransferases, Molecular Microbiology 65, 1258--1275.
    • Bergfeld, A. K., Claus, H., Vogel, U., and MĂźhlenhoff, M. (2007) Biochemical characterization of the polysialic acid-specific O-acetyltransferase NeuO of Escherichia coli K1, The Journal of Biological Chemistry 282, 22217--22227.
    • Findlow, H., Vogel, U., Mueller, J. E., Curry, A., Njanpop-Lafourcade, B. -M., Claus, H., Gray, S. J., Yaro, S., TraorĂŠ, Y., SangarĂŠ, L., Nicolas, P., Gessner, B. D., and Borrow, R. (2007) Three cases of invasive meningococcal disease caused by a capsule null locus strain circulating among healthy carriers in Burkina Faso, The Journal of Infectious Diseases 195, 1071--1077.


    • Stummeyer, K., Schwarzer, D., Claus, H., Vogel, U., Gerardy-Schahn, R., and Mühlenhoff, M. (2006) Evolution of bacteriophages infecting encapsulated bacteria: lessons from Escherichia coli K1-specific phages, Molecular Microbiology 60, 1123--1135.
    • Weber, M. V. R., Claus, H., Maiden, M. C. J., Frosch, M., and Vogel, U. (2006) Genetic mechanisms for loss of encapsulation in polysialyltransferase-gene-positive meningococci isolated from healthy carriers, International Journal of Medical Microbiology: IJMM 296, 475--484.


    • Longworth, E., Fernsten, P., Mininni, T. L., Vogel, U., Claus, H., Gray, S., Kaczmarski, E., and Borrow, R. (2002) O-Acetylation status of the capsular polysaccharides of serogroup Y and W135 meningococci isolated in the UK, FEMS Immunology and Medical Microbiology 32, 119--123.
    • Claus, H., Maiden, M. C. J., Maag, R., Frosch, M., and Vogel, U. (2002) Many carried meningococci lack the genes required for capsule synthesis and transport, Microbiology (Reading, England) 148, 1813--1819.


    • Vogel, U., Claus, H., and Frosch, M. (2000) Rapid serogroup switching in Neisseria meningitidis, The New England Journal of Medicine 342, 219--220.


    • Borrow, R., Claus, H., Chaudhry, U., Guiver, M., Kaczmarski, E. B., Frosch, M., and Fox, A. J. (1998) siaD PCR ELISA for confirmation and identification of serogroup Y and W135 meningococcal infections, FEMS Microbiology Letters 159, 209--214.


    • Borrow, R., Claus, H., Guiver, M., Smart, L., Jones, D. M., Kaczmarski, E. B., Frosch, M., and Fox, A. J. (1997) Non-culture diagnosis and serogroup determination of meningococcal B and C infection by a sialyltransferase (siaD) PCR ELISA, Epidemiology and Infection 118, 111--117.
    • Claus, H., Vogel, U., Mühlenhoff, M., Gerardy-Schahn, R., and Frosch, M. (1997) Molecular divergence of the sia locus in different serogroups of Neisseria meningitidis expressing polysialic acid capsules, Molecular & General Genetics: MGG 257, 28--34.