TY  - JOUR
A1  - Horn, Heike
A1  - Bausinger, Julia
A1  - Staiger, Annette M.
A1  - Sohn, Maximilian
A1  - Schmelter, Christopher
A1  - Gruber, Kim
A1  - Kalla, Claudia
A1  - Ott, M. Michaela
A1  - Rosenwald, Andreas
A1  - Ott, German
T1  - Numerical and Structural Genomic Aberrations Are Reliably Detectable in Tissue Microarrays of Formalin-Fixed Paraffin-Embedded Tumor Samples by Fluorescence In-Situ Hybridization
JF  - PLOS ONE
N2  - Few data are available regarding the reliability of fluorescence in-situ hybridization (FISH), especially for chromosomal deletions, in high-throughput settings using tissue microarrays (TMAs). We performed a comprehensive FISH study for the detection of chromosomal translocations and deletions in formalin-fixed and paraffin-embedded (FFPE) tumor specimens arranged in TMA format. We analyzed 46 B-cell lymphoma (B-NHL) specimens with known karyotypes for translocations of IGH-, BCL2-, BCL6- and MYC-genes. Locus-specific DNA probes were used for the detection of deletions in chromosome bands 6q21 and 9p21 in 62 follicular lymphomas (FL) and six malignant mesothelioma (MM) samples, respectively. To test for aberrant signals generated by truncation of nuclei following sectioning of FFPE tissue samples, cell line dilutions with 9p21-deletions were embedded into paraffin blocks. The overall TMA hybridization efficiency was 94%. FISH results regarding translocations matched karyotyping data in 93%. As for chromosomal deletions, sectioning artefacts occurred in 17% to 25% of cells, suggesting that the proportion of cells showing deletions should exceed 25% to be reliably detectable. In conclusion, FISH represents a robust tool for the detection of structural as well as numerical aberrations in FFPE tissue samples in a TMA-based high-throughput setting, when rigorous cut-off values and appropriate controls are maintained, and, of note, was superior to quantitative PCR approaches.
KW  - mantel cell lymphoma
KW  - amplifications
KW  - abnormalities
KW  - deletions
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116706
SN  - 1932-6203
VL  - 9
IS  - 4
ER  - 
TY  - JOUR
A1  - Benoit, Joshua B.
A1  - Adelman, Zach N.
A1  - Reinhardt, Klaus
A1  - Dolan, Amanda
A1  - Poelchau, Monica
A1  - Jennings, Emily C.
A1  - Szuter, Elise M.
A1  - Hagan, Richard W.
A1  - Gujar, Hemant
A1  - Shukla, Jayendra Nath
A1  - Zhu, Fang
A1  - Mohan, M.
A1  - Nelson, David R.
A1  - Rosendale, Andrew J.
A1  - Derst, Christian
A1  - Resnik, Valentina
A1  - Wernig, Sebastian
A1  - Menegazzi, Pamela
A1  - Wegener, Christian
A1  - Peschel, Nicolai
A1  - Hendershot, Jacob M.
A1  - Blenau, Wolfgang
A1  - Predel, Reinhard
A1  - Johnston, Paul R.
A1  - Ioannidis, Panagiotis
A1  - Waterhouse, Robert M.
A1  - Nauen, Ralf
A1  - Schorn, Corinna
A1  - Ott, Mark-Christoph
A1  - Maiwald, Frank
A1  - Johnston, J. Spencer
A1  - Gondhalekar, Ameya D.
A1  - Scharf, Michael E.
A1  - Raje, Kapil R.
A1  - Hottel, Benjamin A.
A1  - Armisén, David
A1  - Crumière, Antonin Jean Johan
A1  - Refki, Peter Nagui
A1  - Santos, Maria Emilia
A1  - Sghaier, Essia
A1  - Viala, Sèverine
A1  - Khila, Abderrahman
A1  - Ahn, Seung-Joon
A1  - Childers, Christopher
A1  - Lee, Chien-Yueh
A1  - Lin, Han
A1  - Hughes, Daniel S.T.
A1  - Duncan, Elizabeth J.
A1  - Murali, Shwetha C.
A1  - Qu, Jiaxin
A1  - Dugan, Shannon
A1  - Lee, Sandra L.
A1  - Chao, Hsu
A1  - Dinh, Huyen
A1  - Han, Yi
A1  - Doddapaneni, Harshavardhan
A1  - Worley, Kim C.
A1  - Muzny, Donna M.
A1  - Wheeler, David
A1  - Panfilio, Kristen A.
A1  - Jentzsch, Iris M. Vargas
A1  - Jentzsch, IMV
A1  - Vargo, Edward L.
A1  - Booth, Warren
A1  - Friedrich, Markus
A1  - Weirauch, Matthew T.
A1  - Anderson, Michelle A.E.
A1  - Jones, Jeffery W.
A1  - Mittapalli, Omprakash
A1  - Zhao, Chaoyang
A1  - Zhou, Jing-Jiang
A1  - Evans, Jay D.
A1  - Attardo, Geoffrey M.
A1  - Robertson, Hugh M.
A1  - Zdobnov, Evgeny M.
A1  - Ribeiro, Jose M.C.
A1  - Gibbs, Richard A.
A1  - Werren, John H.
A1  - Palli, Subba R.
A1  - Schal, Coby
A1  - Richards, Stephen
T1  - Unique features of a global human ectoparasite identified through sequencing of the bed bug genome
JF  - Nature Communications
N2  - The bed bug, Cimex lectularius, has re-established itself as a ubiquitous human ectoparasite throughout much of the world during the past two decades. This global resurgence is likely linked to increased international travel and commerce in addition to widespread insecticide resistance. Analyses of the C. lectularius sequenced genome (650 Mb) and 14,220 predicted protein-coding genes provide a comprehensive representation of genes that are linked to traumatic insemination, a reduced chemosensory repertoire of genes related to obligate hematophagy, host–symbiont interactions, and several mechanisms of insecticide resistance. In addition, we document the presence of multiple putative lateral gene transfer events. Genome sequencing and annotation establish a solid foundation for future research on mechanisms of insecticide resistance, human–bed bug and symbiont–bed bug associations, and unique features of bed bug biology that contribute to the unprecedented success of C. lectularius as a human ectoparasite.
KW  - human ectoparasite
KW  - bed bug
KW  - Cimex lectularius
KW  - genome
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166221
VL  - 7
IS  - 10165
ER  - 
TY  - JOUR
A1  - Dumont, Martine
A1  - Weber-Lassalle, Nana
A1  - Joly-Beauparlant, Charles
A1  - Ernst, Corinna
A1  - Droit, Arnaud
A1  - Feng, Bing-Jian
A1  - Dubois, Stéphane
A1  - Collin-Deschesnes, Annie-Claude
A1  - Soucy, Penny
A1  - Vallée, Maxime
A1  - Fournier, Frédéric
A1  - Lemaçon, Audrey
A1  - Adank, Muriel A.
A1  - Allen, Jamie
A1  - Altmüller, Janine
A1  - Arnold, Norbert
A1  - Ausems, Margreet G. E. M.
A1  - Berutti, Riccardo
A1  - Bolla, Manjeet K.
A1  - Bull, Shelley
A1  - Carvalho, Sara
A1  - Cornelissen, Sten
A1  - Dufault, Michael R.
A1  - Dunning, Alison M.
A1  - Engel, Christoph
A1  - Gehrig, Andrea
A1  - Geurts-Giele, Willemina R. R.
A1  - Gieger, Christian
A1  - Green, Jessica
A1  - Hackmann, Karl
A1  - Helmy, Mohamed
A1  - Hentschel, Julia
A1  - Hogervorst, Frans B. L.
A1  - Hollestelle, Antoinette
A1  - Hooning, Maartje J.
A1  - Horváth, Judit
A1  - Ikram, M. Arfan
A1  - Kaulfuß, Silke
A1  - Keeman, Renske
A1  - Kuang, Da
A1  - Luccarini, Craig
A1  - Maier, Wolfgang
A1  - Martens, John W. M.
A1  - Niederacher, Dieter
A1  - Nürnberg, Peter
A1  - Ott, Claus-Eric
A1  - Peters, Annette
A1  - Pharoah, Paul D. P.
A1  - Ramirez, Alfredo
A1  - Ramser, Juliane
A1  - Riedel-Heller, Steffi
A1  - Schmidt, Gunnar
A1  - Shah, Mitul
A1  - Scherer, Martin
A1  - Stäbler, Antje
A1  - Strom, Tim M.
A1  - Sutter, Christian
A1  - Thiele, Holger
A1  - van Asperen, Christi J.
A1  - van der Kolk, Lizet
A1  - van der Luijt, Rob B.
A1  - Volk, Alexander E.
A1  - Wagner, Michael
A1  - Waisfisz, Quinten
A1  - Wang, Qin
A1  - Wang-Gohrke, Shan
A1  - Weber, Bernhard H. F.
A1  - Devilee, Peter
A1  - Tavtigian, Sean
A1  - Bader, Gary D.
A1  - Meindl, Alfons
A1  - Goldgar, David E.
A1  - Andrulis, Irene L.
A1  - Schmutzler, Rita K.
A1  - Easton, Douglas F.
A1  - Schmidt, Marjanka K.
A1  - Hahnen, Eric
A1  - Simard, Jacques
T1  - Uncovering the contribution of moderate-penetrance susceptibility genes to breast cancer by whole-exome sequencing and targeted enrichment sequencing of candidate genes in women of European ancestry
JF  - Cancers
N2  - Rare variants in at least 10 genes, including BRCA1, BRCA2, PALB2, ATM, and CHEK2, are associated with increased risk of breast cancer; however, these variants, in combination with common variants identified through genome-wide association studies, explain only a fraction of the familial aggregation of the disease. To identify further susceptibility genes, we performed a two-stage whole-exome sequencing study. In the discovery stage, samples from 1528 breast cancer cases enriched for breast cancer susceptibility and 3733 geographically matched unaffected controls were sequenced. Using five different filtering and gene prioritization strategies, 198 genes were selected for further validation. These genes, and a panel of 32 known or suspected breast cancer susceptibility genes, were assessed in a validation set of 6211 cases and 6019 controls for their association with risk of breast cancer overall, and by estrogen receptor (ER) disease subtypes, using gene burden tests applied to loss-of-function and rare missense variants. Twenty genes showed nominal evidence of association (p-value < 0.05) with either overall or subtype-specific breast cancer. Our study had the statistical power to detect susceptibility genes with effect sizes similar to ATM, CHEK2, and PALB2, however, it was underpowered to identify genes in which susceptibility variants are rarer or confer smaller effect sizes. Larger sample sizes would be required in order to identify such genes.
KW  - breast cancer
KW  - genetic susceptibility
KW  - whole-exome sequencing
KW  - moderate-penetrance genes
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281768
SN  - 2072-6694
VL  - 14
IS  - 14
ER  - 
TY  - JOUR
A1  - Hassouna, I.
A1  - Ott, C.
A1  - Wüstefeld, L.
A1  - Offen, N.
A1  - Neher, R. A.
A1  - Mitkovski, M.
A1  - Winkler, D.
A1  - Sperling, S.
A1  - Fries, L.
A1  - Goebbels, S.
A1  - Vreja, I. C.
A1  - Hagemeyer, N.
A1  - Dittrich, M.
A1  - Rossetti, M. F.
A1  - Kröhnert, K.
A1  - Hannke, K.
A1  - Boretius, S.
A1  - Zeug, A.
A1  - Höschen, C.
A1  - Dandekar, T.
A1  - Dere, E.
A1  - Neher, E.
A1  - Rizzoli, S. O.
A1  - Nave, K.-A.
A1  - Sirén, A.-L.
A1  - Ehrenreich, H.
T1  - Revisiting adult neurogenesis and the role of erythropoietin for neuronal and oligodendroglial differentiation in the hippocampus
JF  - Molecular Psychiatry
N2  - Recombinant human erythropoietin (EPO) improves cognitive performance in neuropsychiatric diseases ranging from schizophrenia and multiple sclerosis to major depression and bipolar disease. This consistent EPO effect on cognition is independent of its role in hematopoiesis. The cellular mechanisms of action in brain, however, have remained unclear. Here we studied healthy young mice and observed that 3-week EPO administration was associated with an increased number of pyramidal neurons and oligodendrocytes in the hippocampus of similar to 20%. Under constant cognitive challenge, neuron numbers remained elevated until >6 months of age. Surprisingly, this increase occurred in absence of altered cell proliferation or apoptosis. After feeding a \(^{15}\)N-leucine diet, we used nanoscopic secondary ion mass spectrometry, and found that in EPO-treated mice, an equivalent number of neurons was defined by elevated \(^{15}\)N-leucine incorporation. In EPO-treated NG2-Cre-ERT2 mice, we confirmed enhanced differentiation of preexisting oligodendrocyte precursors in the absence of elevated DNA synthesis. A corresponding analysis of the neuronal lineage awaits the identification of suitable neuronal markers. In cultured neurospheres, EPO reduced Sox9 and stimulated miR124, associated with advanced neuronal differentiation. We are discussing a resulting working model in which EPO drives the differentiation of non-dividing precursors in both (NG2+) oligodendroglial and neuronal lineages. As endogenous EPO expression is induced by brain injury, such a mechanism of adult neurogenesis may be relevant for central nervous system regeneration.
KW  - neural stem-cells
KW  - recombinat-human-erythropoietin
KW  - cognitive functions
KW  - pyramidal neurons
KW  - nervous-sytem
KW  - brain-injury
KW  - mouse-brain
KW  - progenitors
KW  - mice
KW  - memory
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186669
VL  - 21
IS  - 12
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Bender, L.
A1  - Blum, G.
A1  - Schmittroth, M.
A1  - Achtmann, M.
A1  - Tschäpe, H.
A1  - Hacker, Jörg
T1  - Virulence patterns and long range mapping of extraintestinal Escherichia coli K1, K5 and K100 isolates: Use of pulse field gel electrophoresis
N2  - A total of 127 extraintestinal Escherichia coli strains of the capsule serotypes Kl, KS, and KlOO from human and animal sources were analyzed for DNA sequences specific for the genes for various adhesins (P fimbriae fpap] and P-related sequences fprs], S fimbriae [s/a)/FlC fimbriae [foc], and type I fimbriae lfim]), aerobactin (aer), and hemolysin (hly). The expression of corresponding virulence factors was also tested. Twenty-four selected strains were analyzed by long-range DNA mapping to evaluate their genetic relationships. DNA sequences for the adhesins were often found in strains not expressing them, while strains with hemolysin and aerobactin genes usually did express them. Different isolates of the same serotype orten expressed different virulence patterns. The use of virulence-associated gene probes for Southern hybridization with genomic DNA fragments separated by pulsed-field gel electrophoresis revealed that a highly heterogeneous restriction fragment length and hybridization pattern existed even within strains of the same serotype. Long-range DNA mapping is therefore useful for the evaluation of genetic relatedness among individual isolates and facilitates the performance of .precise molecular epidemiology.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59738
ER  - 
TY  - JOUR
A1  - Aukema, Sietse M.
A1  - Kreuz, Markus
A1  - Kohler, Christian W.
A1  - Rosolowski, Maciej
A1  - Hasenclever, Dirk
A1  - Hummel, Michael
A1  - Küppers, Ralf
A1  - Lenze, Diddo
A1  - Ott, German
A1  - Pott, Christiane
A1  - Richter, Julia
A1  - Rosenwald, Andreas
A1  - Szczepanowski, Monika
A1  - Schwaenen, Carsten
A1  - Stein, Harald
A1  - Trautmann, Heiko
A1  - Wessendorf, Swen
A1  - Trümper, Lorenz
A1  - Loeffler, Markus
A1  - Spang, Rainer
A1  - Kluin, Philip M.
A1  - Klapper, Wolfram
A1  - Siebert, Reiner
T1  - Biological characterization of adult MYC-translocation-positive mature B-cell lymphomas other than molecular Burkitt lymphoma
JF  - Haematologica
N2  - Chromosomal translocations affecting the MYC oncogene are the biological hallmark of Burkitt lymphomas but also occur in a subset of other mature B-cell lymphomas. If accompanied by a chromosomal break targeting the BCL2 and/or BCL6 oncogene these MYC translocation-positive (MYC+) lymphomas are called double-hit lymphomas, otherwise the term single-hit lymphomas is applied. In order to characterize the biological features of these MYC+ lymphomas other than Burkitt lymphoma we explored, after exclusion of molecular Burkitt lymphoma as defined by gene expression profiling, the molecular, pathological and clinical aspects of 80 MYC-translocation-positive lymphomas (31 single-hit, 46 double-hit and 3 MYC+-lymphomas with unknown BCL6 status). Comparison of single-hit and double-hit lymphomas revealed no difference in MYC partner (IG/non-IG), genomic complexity, MYC expression or gene expression profile. Double-hit lymphomas more frequently showed a germinal center B-cell-like gene expression profile and had higher IGH and MYC mutation frequencies. Gene expression profiling revealed 130 differentially expressed genes between BCL6(+)/MYC+ and BCL2(+)/MYC+ double-hit lymphomas. BCL2(+)/MYC+ double-hit lymphomas more frequently showed a germinal center B-like gene expression profile. Analysis of all lymphomas according to MYC partner (IG/non-IG) revealed no substantial differences. In this series of lymphomas, in which immunochemotherapy was administered in only a minority of cases, single-hit and double-hit lymphomas had a similar poor outcome in contrast to the outcome of molecular Burkitt lymphoma and lymphomas without the MYC break. Our data suggest that, after excluding molecular Burkitt lymphoma and pediatric cases, MYC+ lymphomas are biologically quite homogeneous with single-hit and double-hit lymphomas as well as IG-MYC and non-IG-MYC+ lymphomas sharing various molecular characteristics.
KW  - Rituximab plus
KW  - cyclophsophamide
KW  - c-myc
KW  - gene expression
KW  - genomic aberrations
KW  - follicular lymphoma
KW  - prognostic factor
KW  - poor prognosis
KW  - grade 3B
KW  - distinct
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116882
SN  - 1592-8721
VL  - 99
IS  - 4
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Schmoll, T.
A1  - Goebel, W.
A1  - Van Die, I.
A1  - Hacker, Jörg
T1  - Comparison of the genetic determinant coding for the S-fimbrial adhesin (sfa) of Escherichia coli to other chromosomally encoded fimbrial determinants
N2  - DNA probes specific for different regions of the S-fimbrial adhesin (sja) determinant were constructed and hybridized with DNA sequences coding for P (F8 and F13), mannose-sensitive hemagglutinating type 1 (FlA), and FlC fimbriae. While the sfa and F1C DNA determinants exhibited homology along their entire lengths, the P-fimbrial and type 1-fimbrial determinants exhibited homology to regions of the sfa duster responsible for the control of transcription and, to a minor extent, to regions coding for proteins involved in biogenesis and/or adhesion of the fimbriae and for the N-terminal part of the fimbrillin subunit.
KW  - Infektionsbiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59499
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Hoschützky, H.
A1  - Jann, K.
A1  - Van Die, I.
A1  - Hacker, Jörg
T1  - Gene clusters for S fimbrial adhesin (sfa) and F1C Fimbriae (foc) of Escherichia coli: Comparative aspects of structure and function
N2  - Fimbrial 8dhesins en8ble b8cteria to 8ttach t9 eucaryotic ceU~. The genetic determin8nts for S fimbrial 8dhesins (sja) an.d for FlC ("pseudotype I") fimbri8e ifoc) were compared. Sfa and FlC represent functionally distinct 8dbesins in tbeir receptor specificities. Nevertheless, 8 high degree of bomology between both determin8nts was found on the basis of DNA-DNA hybridizations. Characteristic difl'erences in the restriCtion maps of tbe corresponding gene clusters, bowever, were visible in regions coding for the fimbrial subunits and for the S-specific 8dhesin. While a plasmid carrying the geneiic deternlinant for FlC fimbri8e was 8ble to complement transposon-induced sfa mutants, 8 plasmid carrying tbe genetic determin8nt for 8 tbird 8dht$in type, termed P fimbriae, was un8ble to do so. Proximal sfa-specific sequences carrying the S fimbrial st'"uctural gene were fused to sequences representing tbe di$tal part of the foc gene cluster to form 8 hybrid cluster, and tbe foc proxim~ region coding for tbe structural protein was Iigated to sfa distal sequences to form 8 second hybrid. Botb hybrid clones produced intact fimbriae. Anti-FlC monoclonal8ntibodies (MAbs) only recognized clones which produced FlC fimbriae, and an ~ti-S 8dhesin MAb marked clones whicb expressed the S adhesin. Bowever, one of four other anti-S fimbri8e-specific MAbs reacted witb both fimbrial structures, S and FlC, indicating 8 common epitope on both antigens. The results presented bere ~upport tbe view th8t sfa and foc determinants code for fimbri8e tb8t 8re simil8r in several aspects, wbile the P fimbri8e are members of 8 more distantly rel8ted group.
KW  - Infektionsbiologie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59519
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, M.
A1  - Hof, H.
T1  - Effects of low, subinhibitory concentrations of antibiotics on expression of a virulence gene cluster of pathogenic E. coli by using a wild-type gene fusion
N2  - No abstract available
KW  - Infektionsbiologie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59874
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Bender, L.
A1  - Lück, P. C.
A1  - Meyer, P.
A1  - Hacker, Jörg
T1  - Distribution of Legionellae in a hospital water system: prevalence of immunologically and genetically related Legionella pneumophila serogroup 6 isolates
N2  - A hospital warm water system was monitored for the prcsence and distribution of lcgionellac. Subtyping of ten scletled Legionella pneumophiltl isolates. originating from four different sites in the system by using serogroup spccific antisera in an indircct immunofluorcscence tcst, rcvcalcd that nine of the tcn isolatcs belonged to scrogroup 6, while the remaining one was serogroup I 0. Two monoclonal antibodics (mAbs) spccific for a subgroup of serogroup 6 strains were further used for characterization. None of the strains reactcd with these mAbs. Genome analysis by elaborating Not I profiles using the pulscd field gel electrophoresis (PFGE) technique revealed that nearly all serogroup 6 isolates dcrived from different sites, including a new building connected hy a ring pipe. wcrc identical according to restriction fragment pattems. The patterns were distinguishable from those of the two L. pnewnophi/a serogroup 6 rcfcrencc strains, and ftom that of thc L. pneumophila scrogroup 10 isolate. These data arguc for a relatively homogeneaus L. pneunwpltila serogroup 6 population in the entire watcr system.
KW  - Infektionsbiologie
KW  - Legionella pneumophila
KW  - Hospital water system
KW  - Environmental isolate
KW  - Serogroup
KW  - Genomic profile
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59827
ER  - 
TY  - JOUR
A1  - Bender, L.
A1  - Ott, M.
A1  - Debes, A.
A1  - Rdest, U.
A1  - Heesemann, J.
A1  - Hacker, Jörg
T1  - Distribution, expression and long range mapping of legiolysin gene (lly) specific DNA sequences in Legionellae
N2  - The legiolysin gene (lly) cloned from Legionella pneumophila Philadelphia 1 confers the phenotypes of hemolysis and browning of the culture medium. An internal Uy-specific DNA probe was used in Southern hybridizations for the detection of Uy-specific DNA in the genomes of legioneUae and other gram-negative pathogenic bacteria. Under conditi9ns of high stringency, tlie Uy DNA probe specifically reacted with DNA fragments fr9m L. pneumophiüz isolates; by reducing stringency, hybridization was also observed for all other Legionella strains tested. No hybridization occurred with DNAs isolated from bact~ria of other genera. The Uy genewas mapped by pulsed-field gel electrophoresis to the respective genomic Notl fragments of Legionelltz isolates. By using antilegiolysin monospecific polyclonal antibodies in Western blots (immunoblots), Lly proteins could be detected only in L. pneumophila isolates.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59744
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Messner, P.
A1  - Heesemann, J.
A1  - Marre, R.
A1  - Hacker, Jörg
T1  - Temperature dependent expression of flagella in Legionella
N2  - Legionel/a pneumophila, the causative agent of Legionnaires' disease, was analysed by electron microscopy for production of surface structures. Crystalline surface (S-) layers and fimbriae were not detected, but monotrichous flagellation was seen. Polyclonal antibodies specific for the 47 kDa ftagellin subunit of L. pneumophila Philadelphia I were used in Western blots to confirm the presence of flagella subunits in various L. pneumophila strains tested, but the antiserumalso reacted with flagellin subunits of L. micdlulei, L. hackelia (serogroup (SG) l and SG21 and L./ongbetichae (SG2). Flagellation of Legionellae was shown to be temperature regulated. When the growth temperature of virulent and avirulent variants of strain L. pneumophila Philadelphia I was shifted from 30 oc to either 37 or 41 oc, a decrease in the percentage offtagellated bacteria within the populationwas observed.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59755
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Bender, L.
A1  - Chirinos, E.
A1  - Ehret, W.
A1  - Hacker, Jörg
T1  - Phenotype versus genotype of the 19 kd peptido-glycan associated protein of Legionella (PplA) among Legionellae and other gram-negative bacteria
N2  - The protein PpiA (19 kD) cloned from a genomic library of Legionella pneumophila, Philadelphia 1, represents a peptido-glycan associated outer membrane protein in recombinant E. coli K-12 and L. pneumophila. lt exhibits distinct sequence homology to Iipoproteins of Haemophilus influenzae and E. coli. A ppiA specific DNA probe generated by PCR was used in Southern hybridizations of chromosomal DNA of Legionella strains and other Gram-negative pathogens. Under conditions of high stringency, hybridization could only be observed in L. pneumophila isolates, but alt other Legionella strains tested displayed hybridization under lower stringency. No signals appeared after hybridization of chromosomal DNA from a variety of other bacteria. Using anti-PpiA monospecific polyclonal antibodies in Western blots, it was demonstrated that PpiA related proteins of nearly the same size are found in all L. pneumophila isolates and in a variety of, but not alt, the Legionella species analysed here.
KW  - Infektionsbiologie
KW  - Legionellae
KW  - peptido-glycan associated protein
KW  - ppl
KW  - Southern hybridization
KW  - stringency
KW  - polymerase chain reaction (PCR)
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59768
ER  - 
TY  - JOUR
A1  - Zingler, G.
A1  - Ott, M.
A1  - Blum, G.
A1  - Falkenhagen, U.
A1  - Naumann, G.
A1  - Sokolowska-Köhler, W.
A1  - Hacker, Jörg
T1  - Clonal analysis of Escherichia coli serotype O6 strains from urinary tract infections
N2  - A total of 36 Escherichia coli urinary tract isolates (UTI) of serotype 06, with different combinations of capsule ( K) and flagellin ( H) antigens, were analysed according to the outer membrane pattern (OMP), serum resistance properties, mannose-resistant hemagglutination using various types of erythrocytes, and also for the genetic presence and the expression of Pfimbriae. S fimbriae/F1 C fimbriae, Type 1 fimbriae, aerobactin and hemolysin. Twenty selected strains were further analysed by pulsed field gel electrophoresis (PFGE), elaborating genomic profilas by Xba I cleavage and subsequent Southern hybridization to virulence-associated DNA probes. lt could be shown that 06 UTI isolates represent a highly heterogeneaus group of strains according to the occurrence and combination of these traits. Relatedness an the genetic and the phenotypic Ievei was found for some of the strains exhibiting the same 0: K: H: F serotype. DNA Iang-range mapping further indicated some interesting features, according to the copy number and the genomic linkage of virulence genes.
KW  - Infektionsbiologie
KW  - E. coli serotype 06
KW  - urinary tract infection
KW  - virulence factors
KW  - clonal analysis
KW  - molecular epidemiology
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59786
ER  - 
TY  - JOUR
A1  - Krallmann-Wenzel, U.
A1  - Ott, M.
A1  - Hacker, Jörg
A1  - Schmidt, G
T1  - Chromosomal mapping of genes encoding mannose-sensitive (type I) and mannose-resistant F8(P) fimbriae of Escherichia coli O18:K5:H5
N2  - DNA hybridization experiments demonstrated that the gene clusters encoding the F8 fimbriae (fei) as well as the type I fimbriae (pi/) exist in a single copy on the chromosome of E. coli 018:K5 strain 2980. In conjugation experiments with appropriate donors, the chromosomal site of these gene clusters was determined. The pil genes were mapped close to the gene clusters thr and Jeu controlling the biosynthesis of threonine and leucine, respectively. The fei genes were found to be located close to the galactose operon (gal) between the position 17 and 21 of the E. coli chromosomallinkage map.
KW  - Infektionsbiologie
KW  - Escherichia coli
KW  - F1
KW  - F8 fimbriae
KW  - Gene cloning
KW  - Gene mapping
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59545
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Bender, L.
A1  - Marre, R.
A1  - Hacker, Jörg
T1  - Pulsed field electrophoresis of genomic restriction fragments for the detection of nosocomial Legionella pneumophila in hospital water supplies
N2  - Ten Legionella pneumophUa strains isolated from dift'erent sources were analyzed according to their restriction fragment patterils obtained by cle~vage of gen.omic DNA With Notl and Sftl and separation by pulsed field electrophoresis. Three L. pneumophila isolate~ from a nosocomial outbreak in Lü~k (Germany) and three other L. prreumophilll stralns independently isolated from a water tap located in the care unit where tbe patients were bospitalized 'xhibited identical restricti9n fragment profiles. Therefore, we concluded that these environment81 spee~ens were the source of the Legionnatres dlsease. Anotber two isolates from patients and two strains from the environment, all unrelated to the outJlreak described, sbowed different cleavage patterns.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59672
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, M.
A1  - Ludwig, B.
A1  - Rdest, U.
T1  - Intracellular survival and expression of virulence determinants of Legionella pneumophila
N2  - Legionella pneumophila, the causative agent of Legionnaires' disease is able to live and multiply within macrophages as weil as within protozoan organisms. Legionella strains inhibit phagosome-lysosome fusion and phagosome acidification. By using two different cell culture systems, one derived from human macrophages and the other from human.embryo lung fibro:blastic cells, it is demonstrated that Legionella strains lose their virulence following cultivation in the laboratory. In order to study the mechanisms involved in intracellular survival of Legionella a genomic library of strain Legionella pneumophila Philadelphia I was established in Escherichia coli K-12. By cosmid cloning technique we were able to clone five putative virulence factors, two of which exhibit hemolytic activities and three of which represent membrane-associated proteins of 19, 26 and 60 kilodalton. One of the hemolytic proteins, termed legiolysin, represents a new toxin which specifically lyses human erythrocytes. The other hemolysin exhibits proteolytic properties in addition and is cytolytic for Vero and CHO cells. Further sturlies will be necessary to determine the exact role of the cloned proteins in the pathogenesis of Legionella. Zusammenfassung: Intrazelluläres Überleben
N2  - Intrazelluläres Überleben und Expression der Virulenzdeterminanten vonLegionella pneumophila. L. pneumophila, der Erreger der Legionärskrankheit, hat die Fähigkeit, sowohl in Makrophagen als auch in Protozoen zu leben und sich dort zu vermehret;t. Legionellen inhibieren die Fusion von Phagosom und Lysosom und hemmen die Ansäuerung des Phagosoms. Mit Hilfe von zwei unterschiedlichen Zellkultur-Systemen konnte gezeigt werden, daß Legionella-Stämme ihre Virulenz nach Laborpassage verlieren. Um die Mechanismen zu studieren, die für das intrazelluläre Überleben von Legionellen verantwortlich sind, haben wir eine Genbank des Legionella pneumophila-Stammes Philadelphia I in Escherichia coli K-12angelegt. Mit Hilfe der Cosmid-Klonierungstechnik war es möglich, fünf putative Virulenzfaktoren zu klonieren. Zwei von diesen Faktoren haben hämolytische Eigenschaften und drei sind Membran-assoziierte Proteine mit Molekulargewichten von 19, 26 und 60 kilodalton. Eines der hämolytischen Proteine, das Legiolysin, lysiert spezifisch humane Erythrozyten. Das zweite Hämolysin zeigt zusätzlich proteolytische Eigenschaften und schädigt sowohl Vero- als auch CHO-Zellen. Weitere Studien sind notwendig, um die Rolle der klonierten Proteine in der Pathogenese von Legionella exakt zu bestimmen.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59681
ER  - 
TY  - JOUR
A1  - Ott, M.
A1  - Hacker, Jörg
T1  - Analysis of the variability of S fimbriae expression in an Escherichia coli pathogen.
N2  - The uropathogenic Escherichia coli wiJd..:type strain 536 produces S-fimbriae, P-related fimbriae and type I fimbriae. Using immuno-colony dot and ELISA techniques, variants were detected showing an increased degree of S-fimbrial production. It was demonstrated by itrtmunofluorescence microscopy that in noimal (wild-type) and hyperS- fimbriated E. coli populaiions non-fimbriated cells also · exist, and that the percentage of Sfinibrlated and non-fimbriated bacteria was roughly identica1 in either population. Hyper-Sfimbriated variants could be stably maintained. The transition from wild-type to hyper-S-fimbriation, which occurs spontaneously, is markedly higher than vice versa. Southern blot analysis of the S fimbrial adhesin (sfa) determinants of normal and hyper-fimbriated strains revealed no marked difference in the gene structure.
KW  - Infektionsbiologie
KW  - Escherichia coli
KW  - S-fimbria
KW  - Variability
KW  - Expression
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59695
ER  - 
TY  - JOUR
A1  - Blum, G.
A1  - Ott, M.
A1  - Cross, A.
A1  - Hacker, Jörg
T1  - Virulence determinants of Escherichia coli O6 extraintestinal isolates analysed by Southern hybridizations and DNA long range mapping techniques
N2  - A total of 16 Escherichia coli 06 strains isolated from cases of extraintestinal infections were analysed for the genetic presence and phenotypic expression of fimbrial adhesins ( P, S/FIC, type I), aerobactin and hemolysin. ln addition restriction fragment length polymorphisms (RFLPs) of Xbal-cleaved genomic DNA of seven selected strains, separated by orthogonal field alternation gel electrophoresis {OFAGE) were determined and virulence-associated DNA probes were used for Southern hybridization studies of the Xbal-cleaved genomic DNAs. The virulence characteristics and hybridization patterns obtained differed between the various isolates. ln three isolates hemolysin genes and P fimbrial determinants were located on the same Xbal fragments. Furthermore, multiple copies of FIC determinants (foc) could be detected in two strains. Our data show that the new technique of pulse field electrophoresis tagether with Southern hybridization represents a powerful tool for the genetic analysis of pathogenic bacteria.
KW  - Infektionsbiologie
KW  - E. coli serotype 06
KW  - extraintestinal isolates
KW  - virulence factors
KW  - gene probes
KW  - DNA lang range mapping
KW  - epidemiology
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59717
ER  - 
TY  - JOUR
A1  - Schmoll, T.
A1  - Ott, M.
A1  - Ougeda, B.
A1  - Hacker, Jörg
T1  - Use of a wild-type gene fusion to determine the influence of environmental conditions on expression of the S fimbrial adhesin in an Escherichia coli pathogen
N2  - S fimbrial adhesins (Sfa) enable pathogenic Escherichia coli strains to bind to sialic acid-containing eucaryotic receptor molecules. In order to determine the inftuence of culture conditions on the expression of the sfa determinant in a wild-type strain, we fused the gene lacZ, coding for the enzyme ß-galactosidase, to the sfaA gene, responsible for the major protein subunit of S fimbriae. By using a plasmid which carries an R6K origin, the sfaA-Iac hybrid construct was site-specifically integrated into the chromosome of the uropathogenic E. coli strain S36WT. The expression of lacZ, which was under the control of the sfa wild-type promoters, was now equivalent to the sfa expression of strain S36WT. With the help of this particular wild-type construct, it was demonstrated that the sfa determinant is better expressed on solid media than in liquid broth. The growth rate bad a strong inftuence on Sfa expression under aerobic but not under anaerobic conditions. Production of Sfa was further regulated by catabolite repression, osmolarity, and temperature.
KW  - Infektionsbiologie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59625
ER  -