@article{HackerHofHughesetal.1985,
  author    = {Hacker, J{\"o}rg and Hof, H. and Hughes, C. and Goebel, W.},
  title     = {Salmonella typhimurium strains carrying hemolysin plasmids and cloned hemolysin. genes from Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40309},
  year      = {1985},
  abstract  = {Like all other Salmonella typhimurium strains examined, the smooth variants SF1397 (L T2) and 1366 and also their semi-rough and rough derivatives are non-haemolytic. Nevertheless, two haemolysin (Hly) plasmids of E. coli belonging to the inc groups incFllI,lv (pSU316) and incIz (pHly152) were able to be introduced into these strains by conjugation and stably maintained. A considerable percentage of the Hly+ transconjugants obtained had lost parts of their O-side chains, a result of selection for the better recipient capability of « semi-rough» variants rather than the direct influence of the Hly+ plasmids themselves. In contrast to the incF1lI1V plasmid pSU316, which exhibited higher conjugation rates with rough recipients, the incIz plasmid pHly152 was accepted best by smooth strains. Transformation with cloned E. coli haemolysin (hly) determinant was inefficient ( <10-8) for smooth strains, but 102-103 times higher for rough recipients, and was increased by the use of Salmonella-modified DNA. The transform ants and transconjugants were relatively stable and showed the same haemolytic activity as the E. coli donor strains. The virulence of the Hly+ smooth, semi-rough and rough S. typhimurium strains was tested in two mouse models, and neither the mortality rate nor the ability to multiply within the mouse spleen was influenced by the hly determinants.},
  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}
}
@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{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{SchmollHackerGoebel1987,
  author    = {Schmoll, T. and Hacker, J{\"o}rg and Goebel, W.},
  title     = {Nucleotide sequence of the sfaA gene coding for the S fimbrial protein subunit of Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59480},
  year      = {1987},
  abstract  = {The sfaA gene of the uropathogenic Escherichia coli 06 strain 536, which is responsible for the determination of the S fimbrial protein subunit, was sequenced. The structural gene codes for a polypeptide of 180 amino acids including a 24-residue N-terminal signal sequence. A size of 15.95 kDa was calculated for the processed SfaA protein. The nucleotide and deduced amino acid sequences show significant homology to those of the F1C fimbria and, to a lesser extent, of the mannose- sensitive hemagglutinating fimbria (FimA, PilA). Only week homology toP fimbriae subunits (F72 , Pap) was found.},
  subject      = {Infektionsbiologie},
  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{HackerOttSchmidtetal.1986,
  author    = {Hacker, J{\"o}rg and Ott, M. and Schmidt, G. and Hull, R. and Goebel, W.},
  title     = {Molecular cloning of the F8 fimbrial antigen from Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59391},
  year      = {1986},
  abstract  = {The genetic determinant coding for the Pspecific F8 fimbriae was cloned from · the chromosome of the Escherichia coli wild-type strain 2980 (018: K5: H5: FlC, F8). The F8 determinant was further subcloned into the Pstl site of pBR322 and a restriction map was established. In a Southern hybridization experiment identity between the chromosomally encoded F8 determinant of 2980 and its cloned Counterpart was demonstrated. The cloned F8 fimbri{\"a}e and those of the wild type strain consist of a protein subunit of nearly 20 kDa. F8 fimbriated strains were agglutinated by an F8 polyclonal antiserum, caused mannose-resistant hemagglutination and attached to human uroepi thellal cells. The cloned F8 determinant was weil expressed in a variety of host strains.},
  subject      = {Infektionsbiologie},
  language  = {en}
}
@article{HackerUlmerFasskeetal.1987,
  author    = {Hacker, J{\"o}rg and Ulmer, E. and Fasske, E. and Schmidt, G.},
  title     = {Isolation and characterization of coliphage Omega18A specific for Escherichia coli O18ac strains},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73001},
  year      = {1987},
  abstract  = {The bactedophage Q18A, specific for Escherichia coli 018ac srrains, was isolated frorn sewage. The results of host range and conjugation experiments showed that the sensitivity of bacteria to the phage is associated with rhe presence of 018ac antigens. With sorne of rhe 018 strains rhe phage Q18A produces clear Iysis on bacterial lawns only when applied at a high multiplicity and moreover the phage does not multiply. With rhe help of the phage Ql8A, E. coli 0 18ac strains could be divided inro rwo serologically clistinct subgroups called 018A and 018A1• E. coli strains belanging to the sugroup 0 ISAare sensitive to phage Q t8A wheteas bacteria of subgroup A1 are resistanr.},
  subject      = {Escherichia coli},
  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}
}