@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{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{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{OttBenderMarreetal.1991,
  author    = {Ott, M. and Bender, L. and Marre, R. and Hacker, J{\"o}rg},
  title     = {Pulsed field electrophoresis of genomic restriction fragments for the detection of nosocomial Legionella pneumophila in hospital water supplies},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59672},
  year      = {1991},
  abstract  = {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 L{\"u}~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.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{SchmollMorschhaeuserOttetal.1990,
  author    = {Schmoll, T. and Morschh{\"a}user, J. and Ott, M. and Ludwig, B. and Van Die, I. and Hacker, J{\"o}rg},
  title     = {Complete genetic organization and functional aspects of the Escherichia coli S fimbrial adhesin determinant: nucleotide sequence of the genes sfaB, C, D, E, F.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59661},
  year      = {1990},
  abstract  = {The S fimbrial adhesin (sfa) determinant of E. co/i comprises nine genes situated on a stretch of 7.9 kilobases (kb) DNA. Here the nucleotide sequence of the genes sfa B and sfaC situated proximal to the main structural gene sfaA is described. Sfa-LacZ fusions show that the two genes are transcribed in opposite directions. The isolation of mutants in the proximal region of the sfa gene cluster, the construction of sfa-phoA gene fusions and subsequent transcomplementation sturlies indicated that the genes sfaB and sfaC play a role in regulation of the sfa determinant. ln addition the nucleotide sequence of the genes sfa D, sfa E and sfa F situated between the genes sfaA and sfaG responsible for S subunit proteins, were determined. lt is suggested that these genes are involved in transport and assembly of fimbrial subunits. Thus the entire genetic organization of the sfa determinant is presented and compared with the gene clusters coding for P fimbriae (pap), F1 C fimbriae (foc) and type I fimbriae ( fim). The evolutionary relationship of fimbrial adhesin determinants is discussed.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{BenderOttMarreetal.1990,
  author    = {Bender, L. and Ott, M. and Marre, R. and Hacker, J{\"o}rg},
  title     = {Genome analysis of Legionella spp. by orthogonal field alternation gel electrophoresis (OFAGE)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59657},
  year      = {1990},
  abstract  = {Various Legionella isolates from different sources and origins were analysed by orthogonal field alternation gel electrophoresis of Not I cleaved genomic DNA. The genome of L pneumophila Philadelphia I, the original isolate of the epidemics in 1976, exhibits only five Not I fragments. Two virulent derivatives. derived from L pneumophila Philadelphia I. which were obtained by prolonged passage on artificial cuhure media, did not differ from their isogenic virulent strain according the Not I fragment pattern. By summing the lengths of the Notl fragments, the genome size of L. pneumophila Philadelphia I was calculated as approximately 3.9 Mb. Environmental L pneumophila strains exhibited different Not I pattems, as did Legionella strains not belongi'ng to the species pneumophila. The usefulness of DNA long range mapping of Legionella ssp. with Notl for epidemiology and evaluation of their evolutionary rela· tionships is discussed.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{MarreKreftHacker1990,
  author    = {Marre, R. and Kreft, B. and Hacker, J{\"o}rg},
  title     = {Genetically engineered S and F1C fimbriae differ in their contribution to adherence of Escherichia coli to cultured renal tubular cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59644},
  year      = {1990},
  abstract  = {Escherichia coU K-12 strains producing S-fimbrial adhesins, FlC fimbriae, and mutagenized fimbriae were tested in a binding assay with a renal tubular cell line. S-fimbrial adhesins and FlC fimbriae mediated bindlog to tubular cells. The SfaA, SfaG, and SfaS subunits of S fimbriae contributed to attachment. Site-specific mutations in the sfaS gene reduced binding. The Inhibitionprofile of FlC fimbriae resembled that of S fimbriae.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{VenturSchefferHackeretal.1990,
  author    = {Ventur, Y. and Scheffer, J. and Hacker, J{\"o}rg and K{\"o}nig, W.},
  title     = {Effects of adhesins from mannose-resistant Escherichia coli on mediator release from human lymphocytes, monocytes and basophils and from polymorphonuclear granulo-cytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59636},
  year      = {1990},
  abstract  = {We investigated the roJe of Escherichia coU expressing mannose-resistant hemagglutination and adhesins with regard to the induction of leukotrienes from a suspension of human lymphocytes, monocytes, and basophils (LMBs) compared with human polymorphonuclear granulocytes (PMNs). Genetically cloned E. coli strains expressing various types of mannose-resistant hemagglutination (MRH+) were phagocytosed to a higher degree by monocytes than the nonadherent E. coli strain. The various strains dUfered in their capacity to induce a chemiluminescence response, which showed the same pattern for LMBs and PMNs. Stimulation of LMBs with bacteria alone, unlike granulocytes, did not activate the cells for the release of leukotrienes. However, preincubation of LMBs with bacteria decreased subsequent leukotriene formation when the cells were stimulated with calcium ionophore. The inhibitory eft'ect was dependent on the concentration of bacteria used for preincubation as weil as on the preincubation temperature. The various bacterial strains dift'ered in inhibitory potency for mediator release. Preincubation of LMBs with zymosan, opsonized zymosan, the bacterfal peptide FMLP, and peptidoglycan bad no inhibitory eft'ect or even increased subsequent IeukotrieDe formation. Opsonized bacteria were far less inhibitory than nonopsonized bacteria. In contrast to human LMBs, preincubation of human PMNs with mannose-resistant bacteria led to increased leukotriene 84 generation and reduced w-oxidation of leukotriene 84 • Our data soggest that phagocytes (neutrophils, monocytes) respond in a different way for leukotriene formation after Interaction with mannose-resistant E. coli.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{SchmollOttOugedaetal.1990,
  author    = {Schmoll, T. and Ott, M. and Ougeda, B. and Hacker, J{\"o}rg},
  title     = {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},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59625},
  year      = {1990},
  abstract  = {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.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{MorschhaeuserHoschuetzkyJannetal.1990,
  author    = {Morschh{\"a}user, J. and Hosch{\"u}tzky, H. and Jann, K. and Hacker, J{\"o}rg},
  title     = {Functional analysis of the Sialic acid-binding adhesin SfaS of pathogenic Escherichia coli by site-specific mutagenesis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59613},
  year      = {1990},
  abstract  = {The gene coding for the sialic acid-specific adhesin SfaS produced by the S fimbrial adhesin (sfa) determinant of Escherichia coli has been modified by oligonucleotide-directed, site-specific mutagenesis. Lysine 116, arginine 118, and Iysine 122 were replaced by threonine, serine, and threonine, respectively. The mutagenized gene dusters were able to produce S fimbrial adhesin complexes consisting of the S-specific subunit proteins including the adhesin SfaS. The mutant clones were further characterized by hemagglutination and by enzyme-linked immunoassay tests with antifimbria- and anti-adhesin-specific monoclonal antibodies, one of which is able to block S-specific binding (Moch et al., Proc. Natl. Acad. Sei. USA 84:3462-3466, 1987). The lysine-122 mutantclone was indistinguishable from the wild-type clone in these assays. Replacement of Iysine 116 and ai'ginine 118, however, abolished hemagglutination and resulted in clones which showed a weak (Iysine 116) or a negative (arginine 118) reaction with the antiadhesin-specific antibody Al. We therefore suggest that Iysine 116 and arginine 118 have an inßuence on binding of SfaS to the sialic acid residue of the receptor molecule. Substitution of arginine 118 by serine also had a negative efl"ect on the amount of SfaS adhesin proteins isolated from the S fimbrial adhesin complex.},
  subject      = {Infektionsbiologie},
  language  = {en}
}