@article{HackerOttLudwigetal.1991,
  author    = {Hacker, J{\"o}rg and Ott, M. and Ludwig, B. and Rdest, U.},
  title     = {Intracellular survival and expression of virulence determinants of Legionella pneumophila},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59681},
  year      = {1991},
  abstract  = {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: Intrazellul{\"a}res {\"U}berleben},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{OttHacker1991,
  author    = {Ott, M. and Hacker, J{\"o}rg},
  title     = {Analysis of the variability of S fimbriae expression in an Escherichia coli pathogen.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59695},
  year      = {1991},
  abstract  = {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.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{WintermeyerRdestLudwigetal.1991,
  author    = {Wintermeyer, E. and Rdest, U. and Ludwig, B. and Debes, A. and Hacker, J{\"o}rg},
  title     = {Characterization of legiolysin (lly); responsible for hemolytic activity, colour production and fluorescence of Legionella pneumophila},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59706},
  year      = {1991},
  abstract  = {No abstract available},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{BlumOttCrossetal.1991,
  author    = {Blum, G. and Ott, M. and Cross, A. and Hacker, J{\"o}rg},
  title     = {Virulence determinants of Escherichia coli O6 extraintestinal isolates analysed by Southern hybridizations and DNA long range mapping techniques},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59717},
  year      = {1991},
  abstract  = {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.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{LudwigSchmidMarreetal.1991,
  author    = {Ludwig, B. and Schmid, A. and Marre, R. and Hacker, J{\"o}rg},
  title     = {Cloning, genetic analysis and nucleotide sequence of a determinant coding for a 19 kd peptidoglycan-associated protein (Ppl) of Legionella pneumophila},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59721},
  year      = {1991},
  abstract  = {A genomic library of Legionello pneumophihz, the causative agent of Legionnaires disease in humans, was constructed in Escherichill coli K-12, and the recombinant clones were screened by immuno-colony blots with im antiserum raised against heat-killed L. pneumophilo. Twenty-three clones coding for a LegioneUa-specific protein of 19 kDa were isolated. The 19-kDa protein, which represents an outer membrane protein, was found tobe associated with the peptidoglycan layer bothin L. pneumophilo andin the recombinant E. coli clones. This was shown by electrophoresis and Western immunoblot analysis of bacterial cell membrane fractions witb a monospecific polyclonal 19-kDa protein-specific antiserum. Tbe protein was termed peptidoglycan-associated protein of L. pneumophilo (Ppl). The corresponding genetic determinant, ppl, was subcloned on a 1.8-kb Clol fragment. DNA sequence studies revealed that two open reading frames, pplA and pplB, coding for putative proteins of 18~9 and 16.8 kDa, respectively, were located on the Clol fragment. Exonuclease 111 digestion studies confirmed tbat pplA is the gene coding for the peptidoglycan.;.associated 19-kDa protein of L. pneumophilo. The amino acid sequence of PpiA exhibits a high degree of homology to the sequences of the Pal Iipoproteins of E. coli K-12 and liaemophilus injluenvze.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{MollRoellinghoff1991,
  author    = {Moll, Heidrun and R{\"o}llinghoff, Martin},
  title     = {T-cell reactivity to purified lipophosphoglycan from Leishmania major: A model for analysis of the cellular immune response to microbial carbohydrates.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33022},
  year      = {1991},
  abstract  = {The major macromolecule on the surface o/Leishmania majorpromastigotes is a lipophosphoglycan (LPG). This glycoconjugate plays a key role in determining infectivity and survival of para-sites in the mammalian host cell. In addition, L. major LPG is able to induce a host-protective immune response. In this article, we summarise the evidence for recognition of highly purified LPG by T cells and we discuss the potential mechanisms of T-cell Stimulation by this non-protein antigen.},
  language  = {en}
}
@article{VanDieKramerHackeretal.1991,
  author    = {Van Die, I. and Kramer, C. and Hacker, J{\"o}rg and Bergmans, H. and Jongen, W. and Hoekstra, W.},
  title     = {Nucleotide sequence of the genes coding for minor fimbrial subunits of the F1C fimbriae of Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40353},
  year      = {1991},
  abstract  = {F 1 C fimbriae allow uropathogenic Escherichia coli to adhere to specific epithelial surfaces. This adhesive property is probably due to the presence of minor fimbrial components in F1C fimbriae. The foe gene cluster encoding F1C fimbriae has been cloned, as described previously. Here we present the nucleotide sequence (2081 bp) coding for the F 1 C minor fimbria I subunits. The structural genes code for polypeptides of 175 (FocF), 166 (FocG), and 300 (FocH) amino acids. The deduced amino acids of the F 1 C minor subunits were compared with the reported sequences of the minor subunits of other types of fimbriae. The data show that the Foc minor subunits are highly homologous to the corresponding Sfa proteins, whereas homology to the minor subunits of type 1 and P fimbriae is much lower.},
  language  = {en}
}
@article{LueckBenderOttetal.1991,
  author    = {L{\"u}ck, P. Christian and Bender, Larisa and Ott, Manfred and Helbig, J{\"u}rgen H. and Hacker, J{\"o}rg},
  title     = {Analysis of Legionella pneumophila serogroup 6 strains isolated from a hospital warm water supply over a three-year period by using genomic long-range mapping techniques and monoclonal antibodies},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40392},
  year      = {1991},
  abstract  = {Over a period of 3 years, Legionella pneumophila serogroup 6 strains were isolated from warm water outlets and dental units in the Dental Faculty and from the Surgery and Internal Medicine Clinics at the University of Dresden, Dresden, Germany. In the bacteriological unit of the above-mentioned facility, L. pneumophila serogroups 3 and 12 were grown frl,)m warm water specimens. The medical facilities are located in separate buildings connected with a ring pipe warm water system. All L. pneumophila serogroup 6 strains isolated from the warm water supply reacted with a serogroup-specific monoclonal antibody, but not with two other monoclonal antibodies which are subgroup specific, reacting with other serogroup 6 strains. The NolI genomic profiles obtained by pulsed-field gel electrophoresis of 25 serogroup 6 strains isolated from the Dental Faculty over a 3-year period, 1 isolate from the Internal Medicine Clinic, and 4 strains from the Surgery Clinic were identical. Furthermore, all these strains hybridized with a 3OO-kb NolI fragment when a legiolysin (lIy)-specific DNA probe was used. The NolI pattern, however, differed from those of six serogroup 6 strains of other origins, one serogroup 12 strain from the bacteriological unit, and another six unrelated strains of serogroups other than serogroup 6. L. pneumophila serogroup 6 strains which can be divided into only two subgroups by the use of monoclonal antibodies are differentiated in at least six Noli cleavage types obtained by pulsed-field electrophoresis.},
  language  = {en}
}
@article{SchrotenWolskePlogmannetal.1991,
  author    = {Schroten, Horst and Wolske, Anja and Plogmann, Ricarda and Hanisch, Franz-Georg and Hacker, J{\"o}rg and Uhlenbr{\"u}ck, Gerhard and Wahn, Volker},
  title     = {Binding of cloned S-fimbriated E. coli to human buccal epithelial cells-different inhibition of binding by neonatal saliva and adult saliva.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86291},
  year      = {1991},
  abstract  = {Investigations were carried out on the adhesion of cloned S-fimbriated E. coli, labelled with fluoresceinisothiocyanate (FITC) to human buccal epithelial cells. Fluorescence microscopic analysis revealed binding of bacteria to 75-95\% of epithelial cells. Inhibition experiments with fetuin, a 1-acid glycoprotein and N-acetyl neuraminic acid confirmed the specificity of bacterial binding to sialoglycoproteins. Further studies using saliva as an inhibitor resulted in a 4-5 times stronger binding inhibition by newborn saliva in comparison to adult saliva coinciding with a 4-5 times higher content of total N-acetyl neuraminic acid in samples of newborn saliva. In Western blot analysis sialoglycoprotein bands with a molecular weight >200 kD reacting with wheat germ agglutinin (WGA), were only identified in samples of newborn saliva. These bands are classified as mucins on account of molecular weight and staining. These data suggest that saliva mucins could represent a major defense mechanism against bacterial infections at a stage of ontogeny where the secretory IgAsystem is not yet developed.},
  subject      = {Escherichia coli},
  language  = {en}
}
@article{ParkkinenHackerKorhonen1991,
  author    = {Parkkinen, Jaakko and Hacker, J{\"o}rg and Korhonen, Timo K.},
  title     = {Enhancement of tissue plasminogen activator-catalyzed plasminogen activation by Escherichia coli S fimbriae associated with neonatal septicaemia and meningitis.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71566},
  year      = {1991},
  abstract  = {The effect of Escherichia coli strains isolated from blood and cerebrospinal fluid of septic infants on plasminogen activation was studied. These strains typically carry a filamentous surface protein, S fimbria, that has formerly been shown to bind to endothelial cells and interact with plasminogen. The bacteria effectively promoted plasminogen activation by tissue plasminogen activator (t-PA) which was inhibited by e-aminocaproic acid. A recombinant strain expressing S fimbriae accelerated t-PAcatalyzed plasminogen activation to a similar extent as did the wild-type strains whereas the nonfimbriate recipient strain had no effect. After incubation with t-PA and plasminogen, the S-fimbriate strain displayed bacterium-bound plasmin activity whereas the nonfimbriate strain did not. Bacterium-associated plasmin generation was also observed with a strain expressing mutagenized S fimbriae that Iack the cell-binding subunit SfaS but not with a strain lacking the major subunit SfaA. Both t-PA and plasminogen bound to purified S fimbriae in a lysine-dependent manner and purified S fimbriae accelerated t-PA-catalyzed plasminogen activation. The results indicate that E. coli S fimbriae form a complex with t-PA and plasminogen which enhances the rate of plasminogen activation and generates bacterium-bound plasmin. This may promote bacterial invasion and persistence in tissues and contribute to the systemic activation of fibrinolysis in septicaemia.},
  subject      = {Escherichia coli},
  language  = {en}
}