TY  - JOUR
A1  - Bender, L.
A1  - Ott, M.
A1  - Debes, A.
A1  - Rdest, U.
A1  - Heesemann, J.
A1  - Hacker, Jörg
T1  - Distribution, expression and long range mapping of legiolysin gene (lly) specific DNA sequences in Legionellae
N2  - The legiolysin gene (lly) cloned from Legionella pneumophila Philadelphia 1 confers the phenotypes of hemolysis and browning of the culture medium. An internal Uy-specific DNA probe was used in Southern hybridizations for the detection of Uy-specific DNA in the genomes of legioneUae and other gram-negative pathogenic bacteria. Under conditi9ns of high stringency, tlie Uy DNA probe specifically reacted with DNA fragments fr9m L. pneumophiüz isolates; by reducing stringency, hybridization was also observed for all other Legionella strains tested. No hybridization occurred with DNAs isolated from bact~ria of other genera. The Uy genewas mapped by pulsed-field gel electrophoresis to the respective genomic Notl fragments of Legionelltz isolates. By using antilegiolysin monospecific polyclonal antibodies in Western blots (immunoblots), Lly proteins could be detected only in L. pneumophila isolates.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59744
ER  - 
TY  - JOUR
A1  - Bender, L.
A1  - Ott, M.
A1  - Marre, R.
A1  - Hacker, Jörg
T1  - Genome analysis of Legionella spp. by orthogonal field alternation gel electrophoresis (OFAGE)
N2  - 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.
KW  - Infektionsbiologie
KW  - Legionella ssp.
KW  - Genome analysis
KW  - Orthogonal field attenuation gel electrophoresis
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59657
ER  - 
TY  - JOUR
A1  - Berger, Harald
A1  - Hacker, Jörg
A1  - Juarez, Antonio
A1  - Hughes, Colin
A1  - Goebel, Werner
T1  - Cloning of the chromosomal determinants encoding hemolysin production and mannose-resistant hemagglutination in Escherichia coli
N2  - 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.
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40255
ER  - 
TY  - JOUR
A1  - Blum, G.
A1  - Ott, M.
A1  - Cross, A.
A1  - Hacker, Jörg
T1  - Virulence determinants of Escherichia coli O6 extraintestinal isolates analysed by Southern hybridizations and DNA long range mapping techniques
N2  - 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.
KW  - Infektionsbiologie
KW  - E. coli serotype 06
KW  - extraintestinal isolates
KW  - virulence factors
KW  - gene probes
KW  - DNA lang range mapping
KW  - epidemiology
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59717
ER  - 
TY  - JOUR
A1  - Chakraborty, Trinad
A1  - Kathariou, Sophia
A1  - Hacker, Jörg
A1  - Hof, Herbert
A1  - Huhle, Burkhard
A1  - Wagner, Wilma
A1  - Kuhn, Michael
A1  - Goebel, Werner
T1  - Molecular analysis of bacterial cytolysins
N2  - 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.
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40328
ER  - 
TY  - JOUR
A1  - Fischer, G.
A1  - Bang, H.
A1  - Ludwig, B.
A1  - Mann, K. H.
A1  - Hacker, Jörg
T1  - Mip protein of Legionella pneumophila exhibits peptidyl-prolyl cis-trans-isomerase (PPIase) activity
N2  - Legfonells pneumoph/la is an intracellular paraslte which ts able to survtve and multipJy in human monocytes and alveolar macrophages. The Mtp (macrophage lnfectiv1ty potentlator) protein has been shown to be an essential virulente factor. A search of translated nuclelt .acld data ba.ses has shown that the Mip proteJn from strain Wadsworth possesses reglons homologaus to those found in the FK.506-bindfng proteins (FKBPs) of several different eukaryotlc organisms. FKBPs are abte to bind to the fmmunosuppressant macrollde FK506 and possess peptidyf .. prolyl cisltrans Isomerase (PPiase) activlty. The gene coding for the Mlp proteln was cloned from the ehromo. some of L. pneumophila straln Philadelph·a I and sequenced. II was synthesl%ed in Escherichla coll ·K- 12 and alter purlfication it exhibited PPiase activity catalyslng the slow clsltrans lsomerization of prolyl peptlde bonds. ln ollgopeptides. Mip ls inhibi~ted by FK506 and fully reslstant to cyclosporln A, as was also found for the recently characterlzed FKBP-type PPiases of eukaryotes. However, the N-terminal extenslon of Mip and/or the substltutrons of the vari· ab1e amlno acrds ln the C-termlnal FKBP core Iead to variatlons,. when compared with eukaryotlc FKBPs, Jn substrate specfflclty wlth the Oligopeptide substrates of' type Suc-Aia-Xaa-Pro-Phe·4·nitroanUide. Never· theless, the Legionella Mip factor represents a bacte· rial gene product whtch shares some characteristics normally found in eukaryotic proteins. ln view of the activity of PPiases in protein-folding reactlonsf such prokaryotic FKBP analogues may represent a new class of bacterial. pathogenicity factors.
KW  - Infektionsbiologie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59778
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Bender, L.
A1  - Ott, M.
A1  - Wingeder, J.
A1  - Lund, B.
A1  - Marre, R.
A1  - Goebel, W.
T1  - Deletions of chromosomal regions coding for fimbriae and hemolysins occur in vivo and in vitro in various extraintestinal Escherichia coli isolates
N2  - No abstract available
KW  - Infektionsbiologie
KW  - P-fimbriae
KW  - hemolysin
KW  - genomic deletions
KW  - extraintestinal E. coli
KW  - virulence modulation
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59608
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Gadeberg, Ole V.
A1  - Orskov, Ida
T1  - Role of alpha-Hemolysin for the in vitro Phagocytosis and intracellular killing of Escherichia coli
N2  - 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.
N2  - Die Rolle von a-Hämolysin bei der in vitro·Eliminierung von Escherichia coli durch Phagozyten wurde unter Verwendung isogener Stämme einschließlich von a-hämolysierenden Wildstämmen, davon abstammenden Stämmen mit reduzierter a-Hämolysin-Bildung und davon abstammenden nicht hämolysierenden Stämmen untersuche. Phagozytose und intrazelluläre Abtötung der Bakterien durch Granulozyten oder Monozyten im menschlieben Blut wurden u.nter Verwendung von Wachstums-Hemmtechniken gemessen. o:-hämolysierende Stämme wurden in geringerem Maße als isogene Stämme mit einer geringeren Hämolysin-Bildung und isogene nicht hämolysierende Stämme pbago:z.ytiert und ;~bgetötet. Die mit Granulozyten erzielten Ergebnisse waren den bei Monozyten ähnlich, obwohl die Bakterienelimination durch Monozyten geringer war als durch Granulozyten. Diese Ergebnisse deuten stark darauf hin, daß die Bildung von a-Hämolysin ein Mine) ist, mit dem E. coli der Aktivität der Phagozyten durch Schädigung dieser Zellen mit dem Toxin entgegenwirkt.
KW  - Escherichia coli
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73019
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Hof, H.
A1  - Emödy, L.
A1  - Goebel, W.
T1  - Influence of cloned Escherichia coli hemolysin genes, S fimbriae and serum resistance on pathogenicity in different animal models
N2  - The virulence of the uropathogenic E. coli strain 536 (06: K 1 5: H31) which produces the S-fimbrial adhesin (Sfa•), is serum-resistant (Sre+) and hemolytic (Hiy+) and its derivatives were assessed in five different animal models. Cloned hemolysin (h/y) determinants from the Chromosomes of 06,018 and 075 E. colistrains and from the plasmid pHiy152 were introduced into the spontaneaus Sfa-, Sre-, Hly- mutant 536-21 and its Sfa+, Sre+, Hly- variant 536-31. As already demonstrated for the 536-21 strains {lnfect. Immun. 42: 57-63) the 018-hly determinant but not the plasmid-encoded hly determinant of pHiy 1 52 transformed into 536-31 contribute to lethality in a mouse peritonitis modal. Similar results were obtained with both Hlyhost strains and their Hly+ transformants in a chicken embryo test and in a mouse nephropathogenicity assay in which the renal bacterial counts were measured 1 5 min to 8 hours after i.v. infection. S-fimbriae and serum resistance had only a marginal influence in these three in vivo systems. ln centrast all three factors, S-fimbriae, serum resistance and hemolysin, were necessary for full virulence in a respiratory mouse infection assay. ln a subcutaneously-induced sepsis model in the mouse restoration of S-fimbriae and serum resistance and separately chromosomally-encoded hemolysis increased virulence to a Ievel comparable to that of the parental 536 strain.
KW  - Infektionsbiologie
KW  - E. coli hemolysin
KW  - S-fimbriae
KW  - serum resistance
KW  - E. coli virulence
KW  - animal models
KW  - gene cloning
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59423
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Hof, H.
A1  - Hughes, C.
A1  - Goebel, W.
T1  - Salmonella typhimurium strains carrying hemolysin plasmids and cloned hemolysin. genes from Escherichia coli
N2  - 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.
KW  - Salmonella typhimurium
KW  - Plasmid
KW  - Haemolysin
KW  - Escherichia coli
KW  - Virulence
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40309
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Hughes, C.
A1  - Hof, H.
A1  - Goebel, W.
T1  - Cloned hemolysin genes from Escherichia coli that cause urinary tract infection determine different levels of toxicity in mice
N2  - After intraperitoneal injection of mice with Escherichia coli strains isolated from patients with urinary tract infections, the mortality due to hemolytic (Hly+) and nonhemolytic (Hiy-) isolates was 77 and 40%, respectively. Deletion of the chromosomal hemolysin (h/y) determinant in an E. co/i 06:K15:H31 urinary tract infection strain led to a significant reduction in toxicity for mice, and its reintroduction on a recombinant plasmid partially restored the original toxicity. Although introduction of the cloned plasmid pHiy152-encoded hly determinant into the Hly- E. coli 06 mutant strain increased toxicity by only a marginal degree, transformation with the cloned chromosomal hly determinants from two E. coli strains of serotypes 018ac:K5:H- and 075:K95:H? resulted in markedly greater toxicity, even exceeding that of the original Hly+ E. coli 06 wild-type strain.
KW  - Infektionsbiologie
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59330
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Kestler, H.
A1  - Hoschützky, H.
A1  - Jann, K.
A1  - Lottspeich, F.
A1  - Korhonen, T. K.
T1  - Cloning and characterization of the S fimbrial adhesin (SfaII) complex of an Escherichia coli O18:K1 meningitis isolate
N2  - S fimbrial adbesins (Sfa), which are able to recognize sialic acid-containing receptors on eukaryotic cells, are produced by Escherichia coli strains causing urinary tract infections or newbom meningitis. We recently described tbe cloning and molecular cbaracterization of a determinant, termed sftJI, from the chromosome of an E. coli urinary tract infection strain. Herewe present data conceming a S fimbria-specific gene duster, designated sfall, of an E. coli newbom meningitis strain. Like tbe Sfal complex, Sfall consists of tbe major subunit protein SfaA (16 kDa) and the minor subunit proteins SfaG (17 kDa), SfaS (15 kDa), and SfaH (29 kDa). The genes encoding tbe subunit proteins of Sfall were identified and sequenced. Their protein sequences were calculated from the DNA sequences and compared with tbose of the Sfal complex subunits. Altbough the sequences ofthe two major SfaA subunits ditf'ered markedly, tbe sequences ofthe minor subunits sbowed only a few amino acid exchanges (SfaG, SfaH) or were completely identical (SfaS). The introduction of a site-specific mutation into the gene sfaSII and subsequent analysis of an SfaS-negative clone indicated that sfaSII codes for the sialic acid-specific adhesin of tbe meninigitis isolate. These data were confirmed by tbe isolation and characterization of tbe SfaSII protein and the determination of its N-terminal amino acid sequence. The identity between the sialic acid-specific adhesins of Sfal and Sfall revealed that difl'erences between the two Sfa complexes with respect to tbeir capacities to agglutinate erythrocytes must result from sequence alterations of subunit proteins other tban SfaS.
KW  - Infektionsbiologie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59853
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Knapp, S.
A1  - Goebel, W.
T1  - Spontaneous deletions and flanking regions of the chromosomal inherited hemolysin determinant of an Escherichia coli 06 strain
N2  - 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.
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40260
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, M.
A1  - Hof, H.
T1  - Effects of low, subinhibitory concentrations of antibiotics on expression of a virulence gene cluster of pathogenic E. coli by using a wild-type gene fusion
N2  - No abstract available
KW  - Infektionsbiologie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59874
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, M.
A1  - Ludwig, B.
A1  - Rdest, U.
T1  - Intracellular survival and expression of virulence determinants of Legionella pneumophila
N2  - 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: Intrazelluläres Überleben
N2  - Intrazelluläres Überleben und Expression der Virulenzdeterminanten vonLegionella pneumophila. L. pneumophila, der Erreger der Legionärskrankheit, hat die Fähigkeit, sowohl in Makrophagen als auch in Protozoen zu leben und sich dort zu vermehret;t. Legionellen inhibieren die Fusion von Phagosom und Lysosom und hemmen die Ansäuerung des Phagosoms. Mit Hilfe von zwei unterschiedlichen Zellkultur-Systemen konnte gezeigt werden, daß Legionella-Stämme ihre Virulenz nach Laborpassage verlieren. Um die Mechanismen zu studieren, die für das intrazelluläre Überleben von Legionellen verantwortlich sind, haben wir eine Genbank des Legionella pneumophila-Stammes Philadelphia I in Escherichia coli K-12angelegt. Mit Hilfe der Cosmid-Klonierungstechnik war es möglich, fünf putative Virulenzfaktoren zu klonieren. Zwei von diesen Faktoren haben hämolytische Eigenschaften und drei sind Membran-assoziierte Proteine mit Molekulargewichten von 19, 26 und 60 kilodalton. Eines der hämolytischen Proteine, das Legiolysin, lysiert spezifisch humane Erythrozyten. Das zweite Hämolysin zeigt zusätzlich proteolytische Eigenschaften und schädigt sowohl Vero- als auch CHO-Zellen. Weitere Studien sind notwendig, um die Rolle der klonierten Proteine in der Pathogenese von Legionella exakt zu bestimmen.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59681
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, M.
A1  - Schmidt, G.
A1  - Hull, R.
A1  - Goebel, W.
T1  - Molecular cloning of the F8 fimbrial antigen from Escherichia coli
N2  - 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 fimbriäe 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.
KW  - Infektionsbiologie
KW  - Escherichia coli
KW  - antigen
KW  - F8 fimbriae
KW  - gene cloning
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59391
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, Manfred
A1  - Blum, Gabriele
A1  - Marre, Reinhard
A1  - Heesemann, Jürgen
A1  - Tschäpe, Helmut
A1  - Goebel, Werner
T1  - Genetics of Escherichia coli uropathogenicity: Analysis of the O6:K15:H31 isolate 536
N2  - 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.
KW  - Escherichia coli
KW  - Genetik
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-71578
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ott, Manfred
A1  - Wintermeyer, Eva
A1  - Ludwig, Birgit
A1  - Fischer, Gunter
T1  - Analysis of virulence factors of Legionella pneumophila.
N2  - 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.
KW  - Legionella pneumophila
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70620
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Rdest, Ursula
A1  - Wintermeyer, E.
A1  - Ludwig, B.
T1  - Legiolysin, a New Hemolysin from L. pneumophila
N2  - 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.
N2  - Legionella pneum.ophila bildet Exoroxine, Zytolysine, Proteasen oder Hämolysine, die Wirtszellen wie Erythrozyten oder Animalzellen schädigen. Das Gen für ein neues L. pneumophila Hämolysin ohne proteolytische Aktivität wurde identifiziert, in E. coli kloniert und sequenziert. Das Genprodukt wurde durch SDS-Gelelcktropborese analysiert.
KW  - Hämolysin
KW  - Legionella pneumophila
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73070
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Schmidt, G.
A1  - Hughes, C.
A1  - Knapp, S.
A1  - Marget, M.
A1  - Goebel, W.
T1  - Cloning and characterization of genes involved in the production of mannose-resistant, neuraminidase-susceptible (X) fimbriae from an uropathogenic O6:K15:K31 Escherichia coli strain
N2  - The Qropathogenic Escherichia coli strain 536 (06:K15:H31) exhibits a mannose-resistant hemagglutination phenotype (Mrh) with bovine erythrocytes and delayed Mrh with human and guinea pig erythrocytes. Neuraminidase treatment of the erythrocytes abolishes mannose resistant hemagglutination, which is typical for X fimbriae. E. coli strain 536 synthesizes two different fimbriae (Fim phenotype) prQtein subunits, 16.5 and 22 kilodaltons in size. In addition the strain shows mannose-sensitive hemagglutination and common type I (Fl) fimbriae. The cosmid clone E. coli K-12(pANN801) and another nine independently isolated Mrh+ cosmid clones derived from a cosmid gene bank of strain 536 express the 16.5-kilodalton protein band, bot not the 22-kilodalton protein, indicating an association of the Mrh+ property with the "16.5-kilodalton fimbriae." All cosmid clones were fimbriated, and they reacted with antiserum produced against Mrh+ fimbriae of the E. coli strain HB101(pANN801) and lacked mannose-sensitive hemagglutination (Fl) funbriae. From the Mrh fim cosmid DNA pANN801, several subclones coding for hemagglutination and X fimbriae were constructed. Subclones that express both hemagglutination and fimbriae and subclones that only code for the hemagglutination antigen were isolated; subclones that only produce fimbriae were not detected. By transposon Tn5 mutagenesis we demonstrated that about 6.5 kilobases of DNA is required for the Mrh+ Fim+ phenotype, and the 1.5- to 2-kilobase DNA region coding for the structural proteiil of the fimbriae has been mapped adjacent to the region responsible for the Mrh+ phenotype. Two different regions can thus be distinguished in the adhesion determinant, one coding for hemagglutination and the other coding for fimbria formation. Transformation of plasmid DNA from these subclones into a Mrh- Fim- mutant of E. coli 536 and into a galE (rough) strain of Salmonella typhimurium yielded transformants that expressed both hemagglutination and fimbria production.
KW  - Infektionsbiologie
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59353
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Schrettenbrunner, A.
A1  - Schröter, G.
A1  - Schmidt, G.
A1  - Düvel, H.
A1  - Goebel, W.
T1  - 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
N2  - 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.
N2  - E. co/i-Stämme, die von Patienten mit Urogenitaltraktinfektionen (UTI) isoliert werden, weisen oftmals Mannose-sensitive (MS) und Mannose-resistente (MR) Adhärenzfaktoren (Fimbrien) auf. Entsprechend ihrer Rezeptorspezifität können die MR-Adhäsine in verschiedene Gruppen, P, S, M und X unterteilt werden. Vor kurzem haben wir die Determinanten von drei Gruppen der UTI E. coli-Adhäsine, MS, P und S, kloniert und spezifische Antiseren gegen diese Fimbrienantigene hergestellt. 189 Hämagglutinations (HA +)-positive Stämme,. 96 Isolate aus Stuhlproben und 93 Stämme von Patienten mit UTl, wurden mit diesen Fimbrienantigen-spezifischen Antiseren getestet. Sie wurden weiterhin bezüglich ihrer rezeptorspezifischen HA, ihres HA-Musters, dem Vorkommen der 0-Serogruppen 01, 02, 04, 06, 07, 08, 018, 025, 075 ("common 0-serogroups"), die bei Harnwegsisolaten vorherrschen, und der Hämolysinbildung charakterisiert. 68 (73 %) der UTl-Stämme und 50 (52%) der fäkalen lsolate zeigten P-Rezeptorspezifität; 16 ( 17%) uropathogene Stämme und 33 (34%) Stämme aus Stuhlproben prägten S, M oder X-Fimbrienantigene aus. 24% der P-hämagglutinierenden (P+) Stämme reagierten mit P (F8)-spezifischem Antiserum. lm Gegensatz dazu reagierten mehr als drei Viertel der s+ -Stämme mit dem S-spezifischen Antiserum. Das HA-Muster Vl und 018- Antigen wurden meistenteils bei p+ -Stämmen gefunden; die HA-Muster V und Vll und die 0-Antigene 02 (M-Typ), 06 und 018 (S-Typ) wurden vorzugsweise bei p--Stämmen nachgewiesen. Ein hoher Prozentsatz von P-fimbrierten Stämmen zeigte Mannose-sensitive Hämagglutination und Hämolysinbildung.
KW  - Escherichia coli
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72992
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Ulmer, E.
A1  - Fasske, E.
A1  - Schmidt, G.
T1  - Isolation and characterization of coliphage Omega18A specific for Escherichia coli O18ac strains
N2  - 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.
N2  - Der Bakteriophage Q18A, der spezifisch Escherichia coli 018ac Bakterien lysierr, wurde aus Abwasser isoliert. Die Untersuchungen des Wirtsbereichs und Konjugationsversuche zeigten, daß die Sensitivität der Bakterien gegenüber dem Phagen mit dem Vorhandensein des 0 '18ac Antigens assoziiert ist. Bei eir1igen 0 18 Stämmen wird nur bei Anwendung hoher Phagenkonzentrationen eine klare Lysis auf dem Bakterienrasen erzeugt. Darüber hinaus läßt sich der Phage auf diesen Stämmen nicht vermehren. Mit Hilfe des Phagen Q l8A konnten E, wli 0 18ac Stämme in zwei serologische Subgruppen unteneilt werden, die als 0 lHA und 0 l8A 1 bezeichnet werden. E. coli Bakterien der Subgruppe 0 ISA sind gegenüber dem Phagen Ql8A sensitiv und diejenigen der Subgruppe 0 18A 1 sind resistent.
KW  - Escherichia coli
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73001
ER  - 
TY  - JOUR
A1  - Hof, H.
A1  - Christen, A.
A1  - Hacker, Jörg
T1  - Comparative therapeutic activities of Ciprofloxacin, Amoxicillin, Ceftriaxone and Cotrimoxazole in a new model of experimental infection with Escherichia coli
N2  - 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.
N2  - Vergleichende therapeutische Aktivitiiten von Ciprof/oxacin, Amoxicillin, Ceftriaxon und Co-trimoxazol in einem neuen Versuchsmodell fur die experimentelle Infektion mit Escherichia coli. Ein neues Mausmodell fur eine systemische Infektion mit Escherichia coli wird vorgestellt. In anderen Infektionsmodellen mussen 107_108 E. coli pro Maus injiziert werden, was zu einer Intoxikation fUhrt, so daB die Tiere innerhalb von 24 Stunden sterben. In diesem neuen Modell wird eine echte Infektion mit nur 103-104 Bakterien gesetzt, und es folgt dann uber mehrere Tage hinweg eine deutliche Vermehrung der Erreger. Diese kann exakt quantitativ durch die Bestimmung der Keimzahlen in der Leber kontrolliert werden, was eine viel empfindlichere Methode darstellt als die Feststellung von Mortalitatsraten. Weiterhin werden dabei weitaus weniger Mause benotigt, urn eine stichhaltige Aussage zu machen, als fUr eine Bestimmung der LDso erforderlich sind. Der entscheidende Punkt dieses neuen Modells ist, daB die Infektion mit den niedrigen Keimzahlen gebahnt werden muB. Diesgeschieht dadurch, daB das Inokulum in verflussigtem Agar suspendiert wird, bevor es subkutan injiziert wird. Der Infektionsverlauf ist wesentlich abhiingig von der Natur des verwendeten E. coli-Stammes. Wahrend z. B. ein hamolytischer, uropathogener Stamm so virulent ist, daB die Tiere einer fulminanten Infektion nach Injektion von nur 103 Keimen erliegen, ist eine nicht-hamolytische Mutante dieses Stammes vollig avirulent und kann sich selbst trotz der Beigabe von Agar nicht vermehren. Der hamolytische Stamm E. coli A TCC 25922 ist bezuglich seiner Virulenz intermediar, d. h. nach Injektion von 104 Bakterien nimmt die Keimzahl pro Leber standig zu und die Tiere sterben nach funf bis sieben Tagen an dieser Infektion. Gerade dieser Infektionsverlauf kann durch tagliche Verabreichung von Chemotherapeutika beeinfluBt weT-den. Ciprofloxacin, Ceftriaxon und Co-trimoxazol sind in der Lage, eine Ausheilung zu erzielen. Amoxicillin hat nach oraler Gabe nur eine maBige Wirkung aut die Infektion mit diesem ATCC-Stamm, der auch gegen Amoxicillin relativ resistent ist.
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40313
ER  - 
TY  - JOUR
A1  - Hof, H.
A1  - Emmerling, P.
A1  - Hacker, Jörg
A1  - Hughes, C.
T1  - The role of macrophages in primary and secondary infection of mice with Salmonella typhimurium
N2  - 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.
KW  - Macrophage
KW  - Salmonella typhimurium
KW  - Dextran sulphate
KW  - Mouse
KW  - 0 antigen
KW  - Bordeiella pertussis
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40248
ER  - 
TY  - JOUR
A1  - Hughes, C.
A1  - Hacker, Jörg
A1  - Düvel, H.
A1  - Goebel, W
T1  - Chromosomal deletions and rearrangements cause coordinate loss of hemolysis, fimbriation and serum resistance in an uropathogenic strain of Escherichia coli
N2  - No abstract available
KW  - Infektionsbiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59470
ER  - 
TY  - JOUR
A1  - Hughes, C.
A1  - Hacker, Jörg
A1  - Roberts, A.
A1  - Goebel, W
T1  - Hemolysin production as a virulence marker in symptomatic and asymptomatic urinary tract infections caused by Escherichia coli
N2  - Potential virulence, as defined by combined Ievels of adhesion to urinary epithelial cells, serum resistance, and mouse toxicity, was assessed for Escherichia coli strains causing symptomatic and asymptomatic urinary tract infections in relation to the carriage of hemolysin and other suspected virulence determinants. Hemolysin production (Hly), associated with certain 0 (04, 06, 018, and 075), K (5), and hemagglutination (VI and VII) antigenic types but not colicin V production (Cva), was evident in 83 and 60% ofisolates in groups possessing high potential virulence andin only 11 and 6% of those with low virulence. Strains of particular 0-types were not more virulent per se, but among the serotypes, specific combinations of virulence factors appeared decisive, e.g., 018 HAVI B/D/G Hly+ K5+t- and 018 HAIIIIIVBN Hly- Cva +t- Kl +t- strains were, respectively, of high and low potential virulence. Isolates with high potential virulence were found to a similar extent in symptomatic and asymptomatic infections.
KW  - Infektionsbiologie
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59346
ER  - 
TY  - JOUR
A1  - Hughes, Colin
A1  - Müller, Dorothee
A1  - Hacker, Jörg
A1  - Goebel, Werner
T1  - Genetics and pathogenic role of Escherichia coli hemolysin
N2  - While clear evidence exists for the direct involvement of cytolysins in the pathogenesis of Gram-positive bacteria, the significance of Gram-negative haemolysins remains unclear. This paper presents briefly data indicating a role for haemolysin production in infections caused by Escherichia coli and also experiments which have allowed an analysis of the molecular basis of the haemolysis among pathogenic and non-pathogenic strains of this species.
KW  - Toxicity ; plasmids
KW  - gene-cloning
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40082
ER  - 
TY  - JOUR
A1  - Knapp, S.
A1  - Hacker, Jörg
A1  - Jarchau, T.
A1  - Goebel, W
T1  - Large, Unstable Inserts in the Chromosome Affect Virulence
Properties Of Uropathogenic Escherichia coli 06 Strain 536
N2  - The hemolytic, uropathogenic Escherichia coli 536 (06:K15:H31) contains two inserts in its chromosome (insert I and insert II), both of which carried hly genes, were rather unstable, and were deleted spontaneously with a frequen~y of 10-3 to 10-4• These inserts were not found in the chromosome of two nonhemolytic E. coli strains, whereas the chromosomal ~equences adjacent to these inserts appeared tobe again homologous in the uropathogenic and two other E. coü strains. Insert I was 75 kilobases in size and was ftanked at both ends by 16 base pairs (bp) (TTCGACTCCTGTGATC) which were arranged in direct orientation. For insert I it was demonstrated that deletion occurred by recombination between the two 16-bp ftanking sequences, since mutants lacking this insert still carried a single copy of the 16-bp sequence in the chromosome. 8oth inserts contained a functional hemolysin determinant. However, the loss of the inserts not only atfected the hemolytic phenotype bot led to a considerable reduction in serum resistance and the loss of mannose-resistant hemagglutination, caused by the presence of S-type funbriae (sja). lt is shown that the Sfa-negative phenotype is due to a block in transcription of the sfa genes. Mutants of strain 536 which lacked both inserts were entirely avirulent when tested in several animal model systems.
KW  - Infektionsbiologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59402
ER  - 
TY  - JOUR
A1  - Knapp, S.
A1  - Then, I.
A1  - Wels, W.
A1  - Michel, W.
A1  - Tschäpe, H.
A1  - Hacker, Jörg
A1  - Goebel, W
T1  - Analysis of the flanking regions from different hemolysin determinants of Escherichia coli
N2  - The haemolysin (hly) determinant of the plasmid pHly152 contains an IS2 element at 469 bp upstream of the hlyC gene. The sequence at the other (right-hand) end (RS) also shows multiple hybridization with the plasmid pHly152 and the chromosome of some Escherichia coli strains but the nucleotide sequence of this region does not reveal the typical properties of an IS element. Similar arrangements in the regions flanking the hly determinant are also found on various Hly plasmids from uropathogenic E. coli strains. Chromosomal hly determinants Iack both flanking sequences (IS2 and RS) in the immediate vicinity of the hly genes. The sequences immediately upstream of the hlyC gene have been determined from several chromosomal hly determinants and compared with the corresponding sequence of the hly determinant of the plasmid pHly152. We show that these sequences, which contain one promoter (left promoter, phlyL) in all hly determinants tested, vary considerably although common sequence elements can still be identified. In contrast, only relatively few nucleotide exchanges have been detected in the adjacent structural hlyC genes. The A + T content of the 200 bp sequence upstream of hlyC is very high (72 mol% A + T) but even the structural hly genes show a considerably higher A + T content (about 60 mol%) than the E. coli chromosome on average (50 mol% A+T) suggesting that the hly determinant may not have originated in E. coli.
KW  - Infektionsbiologie
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59374
ER  - 
TY  - JOUR
A1  - Knapp, Stefan
A1  - Hacker, Jörg
A1  - Then, Irene
A1  - Müller, Dorothee
A1  - Goebel, Werner
T1  - Multiple copies of hemolysin genes and associated sequences in the chromosome of uropathogenic Escherichia coli strains
N2  - 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.
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40278
ER  - 
TY  - JOUR
A1  - Korhonen, T. K.
A1  - Parkkinen, J.
A1  - Hacker, Jörg
A1  - Finne, J.
A1  - Pere, A.
A1  - Rhen, M.
A1  - Holthöfer, H
T1  - Binding of Escherichia coli S fimbriae to human kidney epithelium
N2  - Purified S fimbriae and an Escherichia coli strain carrying the recombinant plasmid pANN801-4 that encodes S fimbriae were tested for adhesion to frozen sections of human kidney. The fimbrlae and the bacteria bound to the same tissue domains, and in both cases the binding was specifically inhibited by the receptor analog of S fimbria, sialyl(a2-3)1actose. S fimbriae bound specifically to the epithelial elements in the kidneys; to the epithelial cells of proximal and distal tubules as weil as of the collecting ducts and to the visceral and parietal glomerular epithelium. In addition, they bound to the vascular endothelium of glomerull and of the renal Interstitium. No blnding to connective tissue elements was observed. The results suggest that the biological functlon of S fimbriae is to mediate the adheslon of E. coli to human epithelial and vascular endothellal ceUs.
KW  - Infektionsbiologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59415
ER  - 
TY  - JOUR
A1  - Krallmann-Wenzel, U.
A1  - Ott, M.
A1  - Hacker, Jörg
A1  - Schmidt, G
T1  - Chromosomal mapping of genes encoding mannose-sensitive (type I) and mannose-resistant F8(P) fimbriae of Escherichia coli O18:K5:H5
N2  - DNA hybridization experiments demonstrated that the gene clusters encoding the F8 fimbriae (fei) as well as the type I fimbriae (pi/) exist in a single copy on the chromosome of E. coli 018:K5 strain 2980. In conjugation experiments with appropriate donors, the chromosomal site of these gene clusters was determined. The pil genes were mapped close to the gene clusters thr and Jeu controlling the biosynthesis of threonine and leucine, respectively. The fei genes were found to be located close to the galactose operon (gal) between the position 17 and 21 of the E. coli chromosomallinkage map.
KW  - Infektionsbiologie
KW  - Escherichia coli
KW  - F1
KW  - F8 fimbriae
KW  - Gene cloning
KW  - Gene mapping
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59545
ER  - 
TY  - JOUR
A1  - Kunin, Calvin M.
A1  - Hua, Tong Hua
A1  - Van Arsdale-White, Laura
A1  - Krishnan, Chandradekar
A1  - Hacker, Jörg
T1  - Isolation of a nicotinamide-requiring clone of Escherichia coli O18:K1:H7 from women with acute cystitis resembles strains found in neonatal meningitis
N2  - During a study of the nutritional requirements of clinical isolates of Escherichia coli, we found that 21 (7.0%) of 301 strains required nicotinamide to grow in minimal medium. The nicotinamide- requiring strains were present in 16 (15.8%) of 101 cultures of urine from young women with acute cystitis, in 5 (5.0%) of 100 stool specimens from healthy adults, and in none of 100 blood samples from adult patients with bacteremia. Most of the strains belonged to serogroup OI8:KI:H7, were hemolytic, possessed type I fimbriae, and exhibited similar patterns of antibiotic susceptibility. Two of the urinary isolates expressed S fimbriae, and all 16 urinary isolates contained the s/aS homologue gene on their chromosomes. One of the stool isolates contained the s/aS gene. The urinary isolates closely resembled a large clone of E. coli that is reportedly associated with neonatal meningitis and sepsis. It may be possible to detect this and related clones by their requirement for nicotinamide and to screen strains for S fimbriae by relatively inexpensive hemagglutination methods, including the use of avian PI antigens to detect mannose- resistant, non-P-fimbriated E. coli; the agglutination of bovine erythrocytes; and the use of bovine mucin to detect sialyl galactosides in S fimbriae.
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40406
ER  - 
TY  - JOUR
A1  - König, B.
A1  - König, W.
A1  - Scheffer, J.
A1  - Hacker, Jörg
A1  - Goebel, W
T1  - Role of Escherichia coli α-hemolysin and bacterial adherence infection - requirement for release of inflammatory mediators from granulocytes and mast cells
N2  - We investigated the role of bacterial mannose-resistant fimbriation of S fimbriae (Firn), mannose-resistant hemagglutination (S-Mrh), and hemolysin (Hiy) production by an Escherichitl coli parent and genetically cloned strains as regards (i) their eß'ect on histamine release from rat mast ceUs and (ii) generation of the chemiluminescence response, leukotriene, and enzyme release from human polymorphonuclear granulocytes. These mediators are involved in the induction of inftammatory disease processes and Iead, e.g., to the enhancement of vascular permeability, chemotaxis, aggregation of granulocytes (leukotriene 8 4), lysosomal enzyme release, and smooth-muscle contraction (leukotrienes C4, D4, and E4). The content of azurophilic and specific granules in polymorphonuclear granulocytes consists of highly reactive enzymes which amplify inflammatory reactions. Washed bacteria (E. coli 764 my:t:, E. coli 21085 Hly:t:, E. coli 536 Hly:t: Firn:~: Mrh:t:), as weil as their culture supernatants, were analyzed at various times during their growth cycle. No differences exist between parent and cloned or mutant strains with respect to their outer . membrane proteins and lipopolysaccharide pattern. Washed bacteria [E. coli 764 and 21085(pANN202-312)] which produced hemolysin, unlike my- strains, induced high Ievels of histamine release from rat mast ceUs and led to a significant chemiluminescence response and enzyme and leukotriene release from human polymorphonuclear granulocytes. Bacterial culture supernatants from Hly+ and secreting strains showed similar results with the exception of E. coli 21085(pANN202-312), which is a hemolysin-producing bot not a secretory strain. Our data soggest a potent role for hernolysin as a stimulus for noncytotoxic mediator release from various cells. Furthermore, we showed that the presence of Firn and S Mrh potentiales mediator release. The simultaneous presence of Mrh and Firn [E. coli 535/2l(pANN801-4)] increased mediator release compared with Mrh+ Firn- strains [E. coli 536/21(pANN801-1)]. E. coli 536/21 (Msh- Mrh- Firn- Hly-) did not induce mediator release. Escherichia coli alpha-hemolysin is a protein that causes in vitro Iysis of erythrocytes from several species of animals (6, 12, 1~18, 23). Hemolysin-producing E. coli strains occur only infrequently in the normal fecal ftora of humans but are often isolated from patients with extraintestinal infections such as urinary tract infections, bacteremia, and septicemia (13, 22, 25, 36-38, 46-48). The high percentage of Hly+ E. coli strains among isolates from patients with urinary tract infections suggested that hemolysin contributes to the virulence of E. coli strains. The role of hemolysin as a virulence factor has been recently demonstrated by using various animal models and cell cultures. Alpha-hemolysin is one of the very few proteins produced by members of the family Enterobacteriaceae that is released extracellulary. The genetic control of alpha-hemolysin production, transport, and release from cells is complex (24, 26, 30). At least four genes located on the bacterial chromosome or on ]arge transmissible plasmids are required to elicit a cell-free hemolytic phenotype. Bobach and Snyder (6) suggested that the existence of alpha-hemolysin complexed with lipopolysaccharide may have important implications in the understanding of its biological effects. In addition to hemolysin production, a variety of factors, e.g., fimbriae, expression of specific hemagglutination, and • Corresponding author. 886 0 and K antigens, may contribute to the vi
KW  - Infektionsbiologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59451
ER  - 
TY  - JOUR
A1  - König, W
A1  - Scheffer, J.
A1  - Bremm, K. D.
A1  - Hacker, Jörg
A1  - Goebel, W.
T1  - The role of bacterial adherence and toxin production from E. coli on leukotriene generation from human polymorphonuclear granulocytes
N2  - No abstract available
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40295
ER  - 
TY  - JOUR
A1  - König, W.
A1  - König, B.
A1  - Scheffer, J.
A1  - Hacker, Jörg
A1  - Goebel, W.
T1  - Role of cloned virulence factors (mannose-resistant hemagglutination, mannose-resistant adhesins) from uropathogenic Escherichia coli strains in release of inflammatory mediators from neutrophils and mast cells
N2  - Genetically cloned E. co/i strains expressing cloned virulence factors were studied with regard to their capability to induce inflammatory mediator release from various target cells. Among the strains were E. co/i strains with mannose-resistant haemagglutination (MRH +) and mannose-resistant adhesins, e.g. E. coli 536/21 pANN 80 I /4, E. coli 536/21 pANN 921 and E. coli 536/21 pANN 801-1. In comparison, E. coli 536/21, E. coli 536/21 pGB 30 int and E. coli Kl2, without and with mannosesensitive haemagglutination (MSH±), and adhesins were studied. The properties of the various strains for human PMN with regard to adherence and phagocytosis, chemiluminescence, 5-lipoxygenase activation of arachidonic acid, leukotriene formation, granular enzyme release and release of histamine from rat mast cells were analysed. It is evident that the various 'biochemical processes of cell activation are dissociated events. The highest chemiluminescence response is obtained with strains expressing MSH+, P-M RH+ or S-M RH+; the presence of S-adhesins suppressed the response. Highest leukotriene formation is obtained with E. coli 536/21 pANN 801-4, while E. coli with MSH was inactive. The concomitant presence of haemolysin secretion enhanced mediator release significantly. Our data suggest a potent role for mannose-resistant haemagglutination (MRH), adhesins and haemolysin as virulence factors in inducing the release of inflammatory mediators.
KW  - Infektionsbiologie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59564
ER  - 
TY  - JOUR
A1  - Linhardt, F.
A1  - Ziebuhr, W.
A1  - Meyer, P.
A1  - Witte, W.
A1  - Hacker, Jörg
T1  - Pulsed-field gel electrophoresis of genomic restriction fragments as a tool for the epidemiological analysis of Staphylococcus aureus and coagulase-negative Staphylococci
N2  - Thirtccn StttJ1hylococcus dw·eus and s: <'pid<'l'· midis strains ohtaincd from nnsc and hand nf twn cmployccs and onc paticnt uf a mcdical ward as weil as two S. hemol.\"licus strains wcrc analyscd according to thcir rcstrktion fmgmcnt lcngth pattcrns ( RFLP) hy pulscd-ficld gcl clcctrophorcsis (PFGE) using thc rcslriction cnzymcs SmaJ and s.. .· tll. Spccics idcntification nf thc isolatcs was pcrformcd hy a systcm which includcs :!O hiochcmical rc"ctions. Furthcrmorc. thc antillintic resistancc pattcrns of thc stmins wcrc dctcrmincd. Whilc scvcral isolatcs cxhihitcd idcnticaf antihiotic susccptihilitics and hiochcmical prnfilcs. diffcrences in thc RFLP wcrc ohtaincd. ln thrcc cascs, S. epidermülis strains colonizing thc skin showcd an idcntical rcstriction profilc as isollltcs from thc mucous mcmhrancs of thc samc pcrson. Wc C(mcludcd that thc analysis of staphylococcal strains hy PFGE is an important cpidcmiolngical tnnl with high discrimination power.
KW  - Infektionsbiologie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59811
ER  - 
TY  - JOUR
A1  - Ludwig, B.
A1  - Schmid, A.
A1  - Marre, R.
A1  - Hacker, Jörg
T1  - Cloning, genetic analysis and nucleotide sequence of a determinant coding for a 19 kd peptidoglycan-associated protein (Ppl) of Legionella pneumophila
N2  - 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.
KW  - Infektionsbiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59721
ER  - 
TY  - JOUR
A1  - Lück, P. Christian
A1  - Bender, Larisa
A1  - Ott, Manfred
A1  - Helbig, Jürgen H.
A1  - Hacker, Jörg
T1  - 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
N2  - 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.
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40392
ER  - 
TY  - JOUR
A1  - Marre, R.
A1  - Hacker, Jörg
T1  - Role of S and common type I-fimbriae of Escherichia coli in experimental upper and lower urinary tract infection
N2  - No abstract available
KW  - Infektionsbiologie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59468
ER  - 
TY  - JOUR
A1  - Marre, R.
A1  - Hacker, Jörg
A1  - Braun, V.
T1  - The cell-bound hemolysin of Serratia marcescens contributes to uropathogenicity
N2  - No abstract available
KW  - Infektionsbiologie
KW  - Serratia marcescens
KW  - uropathogenicity
KW  - hemolysin
KW  - rat
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59576
ER  - 
TY  - JOUR
A1  - Marre, R.
A1  - Hacker, Jörg
A1  - Henkel, W.
A1  - Goebel, W.
T1  - Contribution of cloned virulence factors from uropathogenic E. coli strains to nephropathogenicity in an experimental rat pyelonephritis model
N2  - Escherichia coli 536 (06:K15:H31), which was isolated from a case of urinary tract infection, determines high nephropathogenicity in a rat pyelonephritis system as measured by renal bacterial counts 7 days after infection. The loss of S fimbrial adhesin formation (Sfa-) (mannose-resistant hemagglutination [Mrh-] and fimbria production [Fim-]), serum resistance (Sre-), and hemolysin production (Hly-) in the mutaßt 536-21 led to a dramatic reduction of bacterial counts from almost tOS to only 40 cells per g of kidney. The reintroduction of the cloned S fimbrial adhesin determinant (sfa) increases the virulence of the avirulent mutant strain by a factor of 20; almost the same eß'ect was observed after restoration of serum resistance by Integration of an sja+ recombinant cosmid into the chromosome. Additional reintroduction of the my+ phenotype by Iransformation of two hly determinants increased the virulence of the strains. Demolysin production determined increased renal elimination of leukocytes and erythrocytes. Thus all three determinants investigated, S fimbriae, serum resistance, and hemolysin, contribute to the multifactorial phenomenon of E. coli nephropathogenicity.
KW  - Infektionsbiologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59445
ER  - 
TY  - JOUR
A1  - Marre, R.
A1  - Hacker, Jörg
A1  - Wood, G.
A1  - Schmidt, G.
T1  - Oral vaccination of rats with live avirulent Salmonella derivatives expressing adhesive fimbrial agents of uropathogenic Escherichia coli
N2  - The avirulent Salmonella typhimurium F885 was transformed with a plasmid carrying the cloned S fimbriae genes of a uropathogenic Escherichia coli. The resulting transformant (F885-1) produced efficiently E. coli S fimbriae and was used for live oral vaccination of rats. For comparison rats were immunized subcutaneously with isolated S fimbriae. Both routes of vaccination resulted in a significant lgG antibody response to S fimbriae. In addition live oral vaccination induced a serum lgA response against S fimbriae. After transurethral infection of rats with a S fimbriae producing E. coli a 10-fold reduction of bacterial counts in the kidney was observed in rats orally vaccinated with F885-1 as compared to unvaccinated controls. This study suggests that the avirulent Salmonella F885 may be used as a fimbrial antigen carrier for oral vaccination against renal infections.
KW  - Infektionsbiologie
KW  - Avirulent Salmonella
KW  - S-Fimbriae
KW  - Uropatbcgenie E. coli
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59559
ER  - 
TY  - JOUR
A1  - Marre, R.
A1  - Kreft, B.
A1  - Hacker, Jörg
T1  - Genetically engineered S and F1C fimbriae differ in their contribution to adherence of Escherichia coli to cultured renal tubular cells
N2  - 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.
KW  - Infektionsbiologie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59644
ER  - 
TY  - CHAP
A1  - Moch, Thomas
A1  - Hoschützky, Heinz
A1  - Hacker, Jörg
A1  - Krönke, Klaus-D.
A1  - Jann, Klaus
T1  - Isolation and characterization of the \(\alpha\)-Sialyl-\(\beta\) 2-3-Galactosyl (S)-Specific Adhesin fimbriated Escherichia coli
N2  - 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.
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40330
ER  - 
TY  - JOUR
A1  - Morschhäuser, J.
A1  - Hoschützky, H.
A1  - Jann, K.
A1  - Hacker, Jörg
T1  - Functional analysis of the Sialic acid-binding adhesin SfaS of pathogenic Escherichia coli by site-specific mutagenesis
N2  - 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.
KW  - Infektionsbiologie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59613
ER  - 
TY  - JOUR
A1  - Morschhäuser, J.
A1  - Uhlin, B. E.
A1  - Hacker, Jörg
T1  - Transcriptional analysis and regulation of the sfa determinant coding for S fimbria of pathogenic E. coli strains
N2  - The sfa determinant codes for S fimbrial adhesins which constitute adherence factors of pathogenic Escherichia coli strains. Wehave recently shown that the sfa determinant is transcribed from three prömoters, pA, pB, and pC. In comparison with the promoters pB and pC, promoter pA, which is located in front of the structural gene sfaA, showed very weak activity. Herewe have determined the exact positions ofthe mRNA start points by primer extension studies. We have also shown that mRNAs of 500, 700 and 1400 bases can be detected using oligonucleotide probes specific for the genes sfaB, sfaC and sfaA. SfaB and SfaC arepositive regulators infiuencing fimbriation and the production of the S-specific adhesin which is encoded by the gene sfaS Iocated in the distal half of the determinant. In addition, it is demonstrated that SfaB and SfaC interfere with the regulatory effect of the histone-like protein H-NS, encoded by a locus termed drdX or osmZ. In a drdx+ strain the regulators are necessary for transcription of the sfa determinant. In contrast, sfa expression is activator-independent in a drdx- strain. In this latter genetic background, a substantial fraction of the sfa transcripts is initiated from promoter pA. On the basis of these data we discuss a model for the regulation of this adhesin-specific determinant.
KW  - Infektionsbiologie
KW  - Gene regulation
KW  - Fimbriae
KW  - Adhesion
KW  - Transcription
KW  - trans-activation
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59844
ER  - 
TY  - JOUR
A1  - Morschhäuser, Joachim
A1  - Vetter, Viktoria
A1  - Korhonen, Timo
A1  - Uhlin, Bernt Eric
A1  - Hacker, Jörg
T1  - Regulation and binding properties of S fimbriae cloned from E. coli strains causing urinary tract infection and meningitis
N2  - 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.
KW  - Escherichia coli
KW  - Harnwegsinfekt
KW  - Hirnhautentzündung
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86140
ER  - 
TY  - JOUR
A1  - Moser, I.
A1  - Orskov, I.
A1  - Hacker, Jörg
A1  - Jann, K.
T1  - Characterization of a monoclonal antibody against the fimbrial F8 antigen of Escherichia coli
N2  - A monoclonal lgG 1 antibody against F8 fimbriae was obtained with the hybridoma technique using spieen cells from C3H/f rnice immunised with a fimbrial preparation of Escherichia coli 2980 (018ac: K5: H-: FIC, F8) and Sp 2/0 Ag8 myeloma cells. The hybrid cells were cloned twice by lirniting dilution and grown in tissue culture. The monoclonal antibody was purified from culture supernatants on Protein A Sepharose. lt reacted with F8 fimbriae in colony blot, enzyme-linked immunosorbent assay (ELISA) and immunoblot after electrotransfer from sodium dodecyl sulphate-polyacrylarnide gel electrophoresis (SOS-PAGE) of fimbrial preparations. The antibody bound to and agglutinated F8-fimbriated bacteria.
KW  - Infektionsbiologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59385
ER  - 
TY  - JOUR
A1  - Munoa, F.
A1  - Hacker, Jörg
A1  - Juarez, A.
T1  - Characterization of a chromosomal mutant that blocks hemolysin excretion in Escherichia coli
N2  - We analyzed an Escherichia coli strain which harbours a chromosomal mutation that blocks the hemolysin excretion. Compartmentation studies showed that hemolysin accumulates in the cytoplasm and not in the periplasm. The mutation did not affect the SDS-PAGE protein pattern of the outer membrane, although some alterations were apparent in the periplasmic protein pattern. The mutant strain, E. coli Hsb-1 also failed to export a cloned fimbrial adhesin. The mutation maps in the min. 3.5 of the E. coli genetic map.
KW  - Infektionsbiologie
KW  - Hemolysin excretion
KW  - Escherichia coli
KW  - Mutant
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59534
ER  -