@article{SchneiderDobrindtMiddendorfetal.2011,
  author    = {Schneider, Gy{\"o}rgy and Dobrindt, Ulrich and Middendorf, Barbara and Hochhut, Bianca and Szij{\´a}rt{\´o}, Valeria and Em{\´o}dy, Levente and Hacker, J{\"o}rg},
  title     = {Mobilisation and remobilisation of a large archetypal pathogenicity island of uropathogenic \(Escherichia\) \(coli\) \(in\) \(vitro\) support the role of conjugation for horizontal transfer of genomic islands},
  series = {BMC Microbiology},
  volume    = {11},
  journal   = {BMC Microbiology},
  doi       = {10.1186/1471-2180-11-210},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140975},
  pages     = {210},
  year      = {2011},
  abstract  = {Background: A substantial amount of data has been accumulated supporting the important role of genomic islands (GEIs) - including pathogenicity islands (PAIs) - in bacterial genome plasticity and the evolution of bacterial pathogens. Their instability and the high level sequence similarity of different (partial) islands suggest an exchange of PAIs between strains of the same or even different bacterial species by horizontal gene transfer (HGT). Transfer events of archetypal large genomic islands of enterobacteria which often lack genes required for mobilisation or transfer have been rarely investigated so far. Results: To study mobilisation of such large genomic regions in prototypic uropathogenic E. coli (UPEC) strain 536, PAI II(536) was supplemented with the mob(RP4) region, an origin of replication (oriV(R6K)), an origin of transfer (oriT(RP4)) and a chloramphenicol resistance selection marker. In the presence of helper plasmid RP4, conjugative transfer of the 107-kb PAI II(536) construct occured from strain 536 into an E. coli K-12 recipient. In transconjugants, PAI II(536) existed either as a cytoplasmic circular intermediate (CI) or integrated site-specifically into the recipient's chromosome at the leuX tRNA gene. This locus is the chromosomal integration site of PAI II(536) in UPEC strain 536. From the E. coli K-12 recipient, the chromosomal PAI II(536) construct as well as the CIs could be successfully remobilised and inserted into leuX in a PAI II(536) deletion mutant of E. coli 536. Conclusions: Our results corroborate that mobilisation and conjugal transfer may contribute to evolution of bacterial pathogens through horizontal transfer of large chromosomal regions such as PAIs. Stabilisation of these mobile genetic elements in the bacterial chromosome result from selective loss of mobilisation and transfer functions of genomic islands.},
  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{MorschhaeuserVetterKorhonenetal.1993,
  author    = {Morschh{\"a}user, Joachim and Vetter, Viktoria and Korhonen, Timo and Uhlin, Bernt Eric and Hacker, J{\"o}rg},
  title     = {Regulation and binding properties of S fimbriae cloned from E. coli strains causing urinary tract infection and meningitis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86140},
  year      = {1993},
  abstract  = {S fimbriae are able to recognize receptor molecules containing sialic acid and are produced by pathogenic E. coli strains causing urinary tract infection and menigitis. In order to characterize the corresponding genetic determinant, termed S fimbrial adhesin ( sfa) gene duster, we have cloned the S-specific genes from a urinary pathogen and from a meningitis isolate. Nine genes are involved in the production of S fimbriae, two of these, sfaB and sfaC code for regulatory proteins being necessary for the expression of S fimbriae. Two promoters, PB and Pc, are located in front of these genes. Transcription of the sfa determinant is influenced by activation of the promotersvia SfaB and SfaC, the action of the H-NS protein and an RNaseE-specific mRNA processing. In addition, a third promoter, P A• located in front of the major subunit gene sfaA, can be activated under special circumstances. Four genes of the sfa determinant code for the subunit-specific proteins, SfaA (16 kda), SfaG (17 kda), SfaS (14 kda) and SfaH (29 kda). It was demonstrated that the protein SfaA is the major subunit protein while SfaS is identical to the sialic-acid-specific adhesin of S fimbriae. The introduction of specific mutations into sfaS revealed that a region of six amino acids of the adhesin which includes two lysine and one arginine residues is involved in the receptor specific interaction of S fimbriae. Additionally, it has been shown that SfaS is necessary for the induction of fimbriation while SfaH plays a role in the stringency of binding of S fimbriae to erythrocytes.},
  subject      = {Escherichia coli},
  language  = {en}
}
@article{TschaepeBenderOttetal.1992,
  author    = {Tsch{\"a}pe, Helmut and Bender, Larisa and Ott, Manfred and Wittig, Walter and Hacker, J{\"o}rg},
  title     = {Restriction fragments length polymorphism and virulence pattern of the veterinary pathogen Escherichia coli O139:K82:H1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86131},
  year      = {1992},
  abstract  = {Escherichia coli 0139: K82: H1 strains originating from outbreaks and single cases of oedema disease in pigs were characterized by their genomic restriction fragment length polymorphism (RFLP), their virulence pattern, and by the occurrence as well as the genomic distribution of the determinants for hemolysin (hly) and verotoxins (shiga-like toxins; sltI, sltII). Whereas the RFLPs revealed considerable variation among the E. coli 0139: K82: H1 isolates depending the origin and epidemic source of the strains, the virulence gene slt II was found to be present in nearly all strains in a particular chromosomal region. Similar to RFLPs, the plasmid profiles are useful for epidemiological analysis.},
  subject      = {Escherichia coli},
  language  = {en}
}
@article{HackerOttWintermeyeretal.1993,
  author    = {Hacker, J{\"o}rg and Ott, Manfred and Wintermeyer, Eva and Ludwig, Birgit and Fischer, Gunter},
  title     = {Analysis of virulence factors of Legionella pneumophila.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70620},
  year      = {1993},
  abstract  = {Legionella pneumophila, the causative agent of Legionnaires' disease is a facultative intracellular bacterium, which in the course of human infection multiplies in lung macrophages predominantly manifesting as pneumonia. The natural habitat of Legionella is found in sweet water reservoirs and man-made water systems. Virulent L. pneumophila spontaneously convert to an avirulent status at a high frequency. Genetic approaches have led to the identification of various L. pneumophila genes. The mip (macrophage infectivity potentiator) determinant remains at present the sole established virulence factor. The Mip protein exhibits activity of a peptidyl prolyl cis trans isomerase (PPiase), an enzyme which is able to bind the immunosuppressant FK506 and is involved in protein folding. The recently cloned major outer membrane protein (MOMP) could play a role in the uptake of legionellae by macrophages. Cellular models are useful in studying the intracellular replication of legionellae in eukaryotic cells. Human celllines and protozoan models are appropriate for this purpose. By using U 937 macrophage-like cells and Acanthamoeba castellanii as hosts, we could discriminate virulent and avirulent L. pneumophila variants since only the virulent strain was capable of intracellular growth at 37 oc. By using these systems we further demonstrated that a hemolytic factor cloned and characterized in our laboratory, legiolysin (lly), had no influence on the intracellular growth of L. pneumophila.},
  subject      = {Legionella pneumophila},
  language  = {en}
}
@article{HackerOttBlumetal.1992,
  author    = {Hacker, J{\"o}rg and Ott, Manfred and Blum, Gabriele and Marre, Reinhard and Heesemann, J{\"u}rgen and Tsch{\"a}pe, Helmut and Goebel, Werner},
  title     = {Genetics of Escherichia coli uropathogenicity: Analysis of the O6:K15:H31 isolate 536},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71578},
  year      = {1992},
  abstract  = {E. coli strain 536 (06: K15: H31) isolated from a case of acute pyelonephritis, expresses S-fimbrial adhesins, P-related fimbriae, common type I fimbriae, and hemolysins. The respective chromosomally encoded determinants were cloned by constructing a genomic library of this strain. Furthermore, the strain produces the iron uptake substance, enterocheline, damages HeLa cells, and behaves in a serum-resistant mode. Genetic analysis of spontaneously arising non-hemolytic variants revealed that some of the virulence genes were physically linked to large unstable DNA regions, termed "pathogenicity islands", which were mapped in the respective positions on the E. coli K-12linkage map. By comparing the wild type strain and mutants in in vitro and in vivo assays, virulence features have been evaluated. In addition, a regulatory cross talk between adhesin determinants was found for the wild-type isolate. This particular mode of virulence regulation is missing in the mutant strain.},
  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}
}
@article{HackerRdestWintermeyeretal.1991,
  author    = {Hacker, J{\"o}rg and Rdest, Ursula and Wintermeyer, E. and Ludwig, B.},
  title     = {Legiolysin, a New Hemolysin from L. pneumophila},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73070},
  year      = {1991},
  abstract  = {Legionella pneumophila generares exotoxins, cytolysins, proteases oc hemolysins that darnage host cells llke erythrocytes or rissue cu lrure cells. The gene for a new L. pneumophila hemolysin withour a proteolytic activiry was idemified, cloned in E. coli and sequenced. The gene producr was analysed by SDS-Polyacrylamide-gel-electrophoresis.},
  subject      = {H{\"a}molysin},
  language  = {en}
}
@article{HackerSchrettenbrunnerSchroeteretal.1986,
  author    = {Hacker, J{\"o}rg and Schrettenbrunner, A. and Schr{\"o}ter, G. and Schmidt, G. and D{\"u}vel, H. and Goebel, W.},
  title     = {Characterization of Escherichia coli wild-type strains by means of agglutination with antisera raised against cloned P-, S- and MS-fimbriae antigens, hemagglutination, serotyping and hemolysin-production},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72992},
  year      = {1986},
  abstract  = {E. coli stcains isolated from patients with urinary tcact infecrions (UTn very often possess mannose"sensitive (MS) and mannose-resistant (MR) adherence facmrs (fimbriae). According to their receptor specificity the mannose-resistant adhesins can be divided inm several types, P, S, M and X. We have cloned rhe determinants of rhree groups of UTI E. coli adhesins, MS, p and S, and prepared specific aorisera against the fimbriae antigens. 189 hernagglutination (HA+) -positive stcains, 96 fecal isolates and 93 strains isoJated from UTI . have been tesred with rhese specific antisera and further characterized by receptor specific : HA, HA parteras and further of rhe "common 0 serogroups" 01, 02, 04, 06, 07, 08, 018, ' 025, 075, most prevalenr in UTI, and hemolysin production. · 68 (73 \%) of the UTI srrains a.nd 50 (52\%) of the fecal isolates showed P-receptor specificiry; 16 (17\%) of the uropathogenic bacteria and 33 (34\%) of the fecal strains exhibited S, M or X-fimbriae antigens. 24\% of rhe P-hemagglutinating (P+) strains reacted wirb P (F8)-specific antiserum. In contrast, more than three quaner of the s+-srrains were agglutinated by S-specific antiserum. HA-pattern VJ and 018 amigen were found to be associared with P-fimbriae strains, wbereas HA-pattern V and VII and the 0 anrigens 02 (M-type), 06 and 018 (5-type) occurred most frequently in p- -strains. A high percentage of P-fimbriated strains showed mannose-sensitive hemagglurination and hemolysin production.},
  subject      = {Escherichia coli},
  language  = {en}
}
@article{HackerGadebergOrskov1989,
  author    = {Hacker, J{\"o}rg and Gadeberg, Ole V. and Orskov, Ida},
  title     = {Role of alpha-Hemolysin for the in vitro Phagocytosis and intracellular killing of Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73019},
  year      = {1989},
  abstract  = {The_role of a-hemolysin for the elimination of Eschericbia coli by phagocyres in vitro was investigated using sets of isogenic strains which included wild-type a -hemolyric srrains, derived strains with a reduced production of a-hemolysin and derived nonhemolytic strains. Phagocyrosis and intracellular killing of the bacteria by human blood granulocytes or monocytes were measured using growth inhibition rechniques. a-hemolytic strains were phagocytosed and killed ro a Jesser extent than isogenic strains with a reduced production of o:hemoJysin and isogenic nonhemolytic strains. The results obrained with granulocyres were similar to rhose obtained with monocyres although the elimination of bacteria by monocytes was less than that by granulocytes. These resulcs strongJy suggest that production of ahemolysin is a means by which E. coli counteracrs the activity of phagocytes by injuring these cells with the toxin.},
  subject      = {Escherichia coli},
  language  = {en}
}