@article{WirbelauerHofHacker1988,
  author    = {Wirbelauer, J. and Hof, H. and Hacker, J{\"o}rg},
  title     = {Die Wirkung von Desacetylcefotaxin, einem Metaboliten von Cefotaxim, in vitro und auf die experimentelle Infektion mit Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40348},
  year      = {1988},
  abstract  = {Die MHK-Werte von Desacetylcefotaxim gegen verschiedene, z. T. ampicillinresistente St{\"a}mme von Escherichia coH, die mit Hilfe einer Agardilutionsmethode erhoben wurden, waren h{\"o}her als die von Cefotaxim und Ceftriaxon, jedoch niedriger als die von Cefoxitin. In einem Modell der systemischen Infektion der Maus mit einem plasmidtragenden, betalactamaseproduzierenden Stamm von E. coli f{\"u}hrte die Therapie mit Desacetylcefotaxim zu einer starken Reduktion der Keime pro Leber. Im Vergleich zur Therapie mit Cefotaxim trat die protektive Wirkung aber verlangsamt ein. Desacetylcefotaxim ist also kein unn{\"u}tzes Abbauprodukt von Cefotaxim.},
  language  = {de}
}
@inproceedings{MochHoschuetzkyHackeretal.1987,
  author    = {Moch, Thomas and Hosch{\"u}tzky, Heinz and Hacker, J{\"o}rg and Kr{\"o}nke, Klaus-D. and Jann, Klaus},
  title     = {Isolation and characterization of the \(\alpha\)-Sialyl-\(\beta\) 2-3-Galactosyl (S)-Specific Adhesin fimbriated Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40330},
  year      = {1987},
  abstract  = {The \(\alpha\)-Sialyl-\(\beta\) 2-3-Galactosyl-specific adhesin (S adhesin) was isolated from cells of a recombinant Escherichia coli K-12 strain expressing the S-flmbrial adhesin complex. A crude cell extract was partiaUy dissociated into fimbriae and an adhesin-enriched fraction by heating to 7O°C. From the latter, adhesin was purified to apparent homogeneity (by fast protein liquid chromatography, immunoblot, and NaDodSO\(_4\)/PAGE) by differential ammonium sulfate precipitation, dissociation in 8 M guanidine hydrochloride, and high-resolution anion-exchange chromatography in 8 M urea. The purified adhesin formed an aggregate of M\(_r\)\(\approx\)10\(^6\) that was made up of one type of 12-kDa polypeptide (fimbrillin is 16.5 kDa). It had pI value of 4.7 (fimbriae has a pI value of 6). Adhesin and fimbrillin had different amino add compositions. The purified adhesins agglutinated human and bovine erythrocytes with the same speclfkity as the whole bacteria; purified fimbriae were not adhesive. Monoclonal anti-adhesin and anti-fimbriae antibodies were obtained. Monoclonal antiadhesin, but none of the anti-fimbriae, antibodies inhibited the agglutination of erythrocytes. The anti-adhesive antibodies were used in immuno-gold electron microscopy to localize adhesin exclusively on the fimbriae, with a possible preference to their tips.},
  language  = {en}
}
@article{ChakrabortyKathariouHackeretal.1987,
  author    = {Chakraborty, Trinad and Kathariou, Sophia and Hacker, J{\"o}rg and Hof, Herbert and Huhle, Burkhard and Wagner, Wilma and Kuhn, Michael and Goebel, Werner},
  title     = {Molecular analysis of bacterial cytolysins},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40328},
  year      = {1987},
  abstract  = {Results of molecular and pathogenic studies of three different bacterial hemolysins (cytolysins) are presented. These exoproteins derive from the two gram-negative bacteria Escherichia coli and Aeromonas hydrophila and from the gram-positive pathogen Listeria monocytogenes. The hemolysin of E. coli is determined by an 8-kilobase (kb) region that includes four clustered genes (hlyC, hlyA, hlyB, and hlyD). This hemolysin determinant is part either of large transmissible plasmids or of the chromosome. The genes located chromosomally are found predominantly in E. coli strains that can cause pyelonephritis and/or other extraintestinal infections. A detailed analysis of the chromosomal hly determinants of one nephropathogenic E. coli strain revealed the existence of specific, large chromosomal insertions 75 kb and lOO kb in size that carry the hly genes but that also influence the expression of other virulence properties, i.e., adhesion and serum resistance. The direct involvement of E. coli hemolysin in virulence could be demonstrated in several model systems. The genetic determinants for hemolysin (cytolysin) formation in , A. hydrophila (aerolysin) and L. monocytogenes (listeriolysin) are less complex. Both cytolysins seem to be encoded by single genes, although two loci (aerB and aerC) that affect the expression and activity of aerolysin have been identified distal and proximal to the structural gene for aerolysin (aerA). Cytolysin-negative mutants of both bacteria were obtained by site-specific deletion and/or transposon mutagenesis. These mutants show a drastic reduction in the virulence of the respective bacteria.},
  language  = {en}
}
@article{HofChristenHacker1986,
  author    = {Hof, H. and Christen, A. and Hacker, J{\"o}rg},
  title     = {Comparative therapeutic activities of Ciprofloxacin, Amoxicillin, Ceftriaxone and Cotrimoxazole in a new model of experimental infection with Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40313},
  year      = {1986},
  abstract  = {A new mouse model for systemic infection with Escherichia coli is presented. Whereas in other models 107_108 bacteria have to be injected into an animal to induce toxic effects resulting in death within 24 hours, now, only 103_104 bacteria of an appropriate strain are required to produce a genuine infection characterized by an increase in the bacterial load over several days. The quantitative determination of bacterial counts per liver allows a more sensitive measurement than recording death rates. Furthermore, few animals are required for a definite result in contrast to the LDso determination of other models. The salient point regarding this new model is that conditioning of animals has to be achieved by incorporating the inoculum into agar which is injected subcutaneously. The resulting infection is completely dependent on the E. colicondistrain used. Whereas a hemolytic, uropathogenic strain is so virulent that an overwhelming infection develops within 48 hours after the injection of 103 bacterial cells, a non-hemolytic variant of this strain is completely avirulent, being unable to multiply in spite of the potentiating agar. The hemolytic E. coli strain ATCC 25922 is intermediate in virulence. The bacterial counts per liver increase steadily until death occurs five to seven days after the injection of 104 bacteria. This bacterial infection can be therapeutically influenced by daily treatment with various drugs. Ciprofloxacin, ceftriaxone and co-trimoxazole are able to cure the infection, whereas amoxicillin given orally is only moderately active against this ATCC strain, which is relatively resistant to amoxicillin.},
  language  = {en}
}
@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{KoenigSchefferBremmetal.1985,
  author    = {K{\"o}nig, W and Scheffer, J. and Bremm, K. D. and Hacker, J{\"o}rg and Goebel, W.},
  title     = {The role of bacterial adherence and toxin production from E. coli on leukotriene generation from human polymorphonuclear granulocytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40295},
  year      = {1985},
  abstract  = {No abstract available},
  language  = {en}
}
@article{KnappHackerThenetal.1984,
  author    = {Knapp, Stefan and Hacker, J{\"o}rg and Then, Irene and M{\"u}ller, Dorothee and Goebel, Werner},
  title     = {Multiple copies of hemolysin genes and associated sequences in the chromosome of uropathogenic Escherichia coli strains},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40278},
  year      = {1984},
  abstract  = {The 06 serogroup Escherichia coli strain 536 carries two hemolysin (hly) determinants integrated into the chromosome. The two hly determinants are not completely identical, either functionally or structurally, as demonstrated by spontaneous deletion mutants carrying only one of them and by cloning each of the two determinants separately into cosmid vectors. Each hly determinant is independently deleted at a frequency of 10-4 , leading to variants which exhibit similar levels of internal hemolysin but different amounts of secreted hemolysin. The two hly determinants were also identified in the 04 E. coli strain 519. The three E. coli strains 251, 764, and 768, which belong to the serogroup 018, and the 04 strain 367 harbor a single chromosomal hly determinant, as demonstrated by hybridization with hly-gene-specific probes. However, a hybridization probe derived from a sequence adjacent to the hlyC-proximal end of the plasmid pHlyl52-encoded hly determinant hybridizes with several additional chromosomal bands in hemolytic 018 and 06 E. coli strains and even in E. coli K-12. The size ofthe probe causing the multiple hybridization suggests a 1,500- to 1,800-base pair sequence directly flanking hlyC. Spontaneous hemolysin-negative mutants were isolated from strains 764 and 768, which had lost the entire hly determinant but retained all copies of the hlyC-associated sequence. This sequence is not identical to a previously identified (J. Hacker, S. Knapp, and W. Goebel, J. Bacteriol. 154:1145-1154, 1983) somewhat smaller (about 850 base pairs) sequence flanking the other (hlyBb-proximal) end of the plasmid pHlyl52-encoded hly determinant which, as shown here, exists also in multiple copies in these hemolytic E. coli strains and in at least two copies in E. coli K-12. In contrast to the plasmid-encoded hly determinant which is directly flanked at both ends by these two diJJerent sequences, the chromosomal hly determinants are not immediately flanked by such sequences.},
  language  = {en}
}
@article{HackerKnappGoebel1983,
  author    = {Hacker, J{\"o}rg and Knapp, S. and Goebel, W.},
  title     = {Spontaneous deletions and flanking regions of the chromosomal inherited hemolysin determinant of an Escherichia coli 06 strain},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40260},
  year      = {1983},
  abstract  = {The hemolytic Escherichia coli strain 536 (06) propagates spontaneous hemolysin- negative mutants at relatively high rates (10-3 to 10-4 ). One type of mutant (type I) lacks both secreted (external) and periplasmic (internal) hemolysin activity (HlYex - IHlYin -) and in addition shows no mannose-resistant hemagglutination (Mrh -), whereas the other type (type II) is HlYex -IHIYin + and Mrh +. The genetic determinants for hemolysin production (hly) and for mannose-resistant hemagglutination (mrh) of this strain are located on the chromosome. Hybridization experiments with DNA probes specific for various parts of the hly determinant reveal that mutants of type I have lost the total hly determinant, whereas those of type 11 lack only part of the hlyB that is essential for transport of hemolysin across the outer membrane. Using a probe that contains the end sequence of the plasmid pHly152-encoded hly determinant (adjacent to hlyB), we determined that a related sequence flanks also the hlyB-distal end of the chromosomal hly determinant of E. coli 536. In addition several other similar or even identical sequences are found in the vicinity of the hlyC- and the hlyB-distal ends of both the chromosomal and the plasmid hly determinants.},
  language  = {en}
}
@article{BergerHackerJuarezetal.1982,
  author    = {Berger, Harald and Hacker, J{\"o}rg and Juarez, Antonio and Hughes, Colin and Goebel, Werner},
  title     = {Cloning of the chromosomal determinants encoding hemolysin production and mannose-resistant hemagglutination in Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40255},
  year      = {1982},
  abstract  = {We have cloned the chromosomal hemolysin determinants from Escherichia coli strains belonging to the four O-serotypes 04, 06, 018, and 075, The hemolysin-producing clones were isolated from gene banks of these strains which were constructed by inserting partial Sau3A fragments of chromosomal DNA into the cosmid pJC74. The hemolytic cosmid clones were relatively stable. The inserts were further sub cloned either as Sail fragments in pACYC184 or as BamHI-SaLI fragments in a recombinant plasmid (pANN202) containing cistron C (hlye) of the plasmid-encoded hemolysin determinant. Detailed restriction maps of each of these determinants were constructed, and it was found that, despite sharing overall homology, the determinants exhibited minor specific differences in their structure, These appeared to be restricted to cistron A (hlyA), which is the structural gene for hemolysin. In the gene banks of two of these hemolytic strains, we could also identify clones which carried the genetic determinants for the mannose-resistant hemagglutination antigens Vb and VIc. Both of these fimbrial antigens were expressed in the E. coli K-12 clones to an extent similar to that observed in the wild-type strains. These recombinant cosmids were rather unstable, and, in the absence of selection, segregated at a high frequency.},
  language  = {en}
}
@article{HofEmmerlingHackeretal.1982,
  author    = {Hof, H. and Emmerling, P. and Hacker, J{\"o}rg and Hughes, C.},
  title     = {The role of macrophages in primary and secondary infection of mice with Salmonella typhimurium},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40248},
  year      = {1982},
  abstract  = {Elimination of macrophages with high-molecular dextran sulphate (OS) markedly impairs resistance of mice to primary infection with smooth, virulent strains of Salmonella typhimurium, whereas stimulation of this system by killed Bordetella pertussis organisms increases resistance. In infection with rough, avirulent strains of S. iyphimurium the elimination of macro phages was not followed by an essential loss of resistance, and it appears that other non-specific defence mechanisms, for example the complement system, may have compensated for the lack of macrophages. Macrophages, therefore, play an important role in defence during primary infection with virulent strains. In immunity to challenge infection with S. typhimurium, macrophages play an even more significant role. Treatment with OS completely removes immunity, and both humoral and cell-mediated immune mechanisms seem to require the participation of macrophages.},
  language  = {en}
}