@article{SchrotenWolskePlogmannetal.1991, author = {Schroten, Horst and Wolske, Anja and Plogmann, Ricarda and Hanisch, Franz-Georg and Hacker, J{\"o}rg and Uhlenbr{\"u}ck, Gerhard and Wahn, Volker}, title = {Binding of cloned S-fimbriated E. coli to human buccal epithelial cells-different inhibition of binding by neonatal saliva and adult saliva.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86291}, year = {1991}, abstract = {Investigations were carried out on the adhesion of cloned S-fimbriated E. coli, labelled with fluoresceinisothiocyanate (FITC) to human buccal epithelial cells. Fluorescence microscopic analysis revealed binding of bacteria to 75-95\% of epithelial cells. Inhibition experiments with fetuin, a 1-acid glycoprotein and N-acetyl neuraminic acid confirmed the specificity of bacterial binding to sialoglycoproteins. Further studies using saliva as an inhibitor resulted in a 4-5 times stronger binding inhibition by newborn saliva in comparison to adult saliva coinciding with a 4-5 times higher content of total N-acetyl neuraminic acid in samples of newborn saliva. In Western blot analysis sialoglycoprotein bands with a molecular weight >200 kD reacting with wheat germ agglutinin (WGA), were only identified in samples of newborn saliva. These bands are classified as mucins on account of molecular weight and staining. These data suggest that saliva mucins could represent a major defense mechanism against bacterial infections at a stage of ontogeny where the secretory IgAsystem is not yet developed.}, subject = {Escherichia coli}, language = {en} } @article{ParkkinenHackerKorhonen1991, author = {Parkkinen, Jaakko and Hacker, J{\"o}rg and Korhonen, Timo K.}, title = {Enhancement of tissue plasminogen activator-catalyzed plasminogen activation by Escherichia coli S fimbriae associated with neonatal septicaemia and meningitis.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71566}, year = {1991}, abstract = {The effect of Escherichia coli strains isolated from blood and cerebrospinal fluid of septic infants on plasminogen activation was studied. These strains typically carry a filamentous surface protein, S fimbria, that has formerly been shown to bind to endothelial cells and interact with plasminogen. The bacteria effectively promoted plasminogen activation by tissue plasminogen activator (t-PA) which was inhibited by e-aminocaproic acid. A recombinant strain expressing S fimbriae accelerated t-PAcatalyzed plasminogen activation to a similar extent as did the wild-type strains whereas the nonfimbriate recipient strain had no effect. After incubation with t-PA and plasminogen, the S-fimbriate strain displayed bacterium-bound plasmin activity whereas the nonfimbriate strain did not. Bacterium-associated plasmin generation was also observed with a strain expressing mutagenized S fimbriae that Iack the cell-binding subunit SfaS but not with a strain lacking the major subunit SfaA. Both t-PA and plasminogen bound to purified S fimbriae in a lysine-dependent manner and purified S fimbriae accelerated t-PA-catalyzed plasminogen activation. The results indicate that E. coli S fimbriae form a complex with t-PA and plasminogen which enhances the rate of plasminogen activation and generates bacterium-bound plasmin. This may promote bacterial invasion and persistence in tissues and contribute to the systemic activation of fibrinolysis in septicaemia.}, subject = {Escherichia coli}, language = {en} } @article{SchmollMorschhaeuserOttetal.1990, author = {Schmoll, T. and Morschh{\"a}user, J. and Ott, M. and Ludwig, B. and Van Die, I. and Hacker, J{\"o}rg}, title = {Complete genetic organization and functional aspects of the Escherichia coli S fimbrial adhesin determinant: nucleotide sequence of the genes sfaB, C, D, E, F.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59661}, year = {1990}, abstract = {The S fimbrial adhesin (sfa) determinant of E. co/i comprises nine genes situated on a stretch of 7.9 kilobases (kb) DNA. Here the nucleotide sequence of the genes sfa B and sfaC situated proximal to the main structural gene sfaA is described. Sfa-LacZ fusions show that the two genes are transcribed in opposite directions. The isolation of mutants in the proximal region of the sfa gene cluster, the construction of sfa-phoA gene fusions and subsequent transcomplementation sturlies indicated that the genes sfaB and sfaC play a role in regulation of the sfa determinant. ln addition the nucleotide sequence of the genes sfa D, sfa E and sfa F situated between the genes sfaA and sfaG responsible for S subunit proteins, were determined. lt is suggested that these genes are involved in transport and assembly of fimbrial subunits. Thus the entire genetic organization of the sfa determinant is presented and compared with the gene clusters coding for P fimbriae (pap), F1 C fimbriae (foc) and type I fimbriae ( fim). The evolutionary relationship of fimbrial adhesin determinants is discussed.}, subject = {Infektionsbiologie}, language = {en} } @article{HackerGadebergOrskov1989, author = {Hacker, J{\"o}rg and Gadeberg, Ole V. and Orskov, Ida}, title = {Role of alpha-Hemolysin for the in vitro Phagocytosis and intracellular killing of Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73019}, year = {1989}, abstract = {The_role of a-hemolysin for the elimination of Eschericbia coli by phagocyres in vitro was investigated using sets of isogenic strains which included wild-type a -hemolyric srrains, derived strains with a reduced production of a-hemolysin and derived nonhemolytic strains. Phagocyrosis and intracellular killing of the bacteria by human blood granulocytes or monocytes were measured using growth inhibition rechniques. a-hemolytic strains were phagocytosed and killed ro a Jesser extent than isogenic strains with a reduced production of o:hemoJysin and isogenic nonhemolytic strains. The results obrained with granulocyres were similar to rhose obtained with monocyres although the elimination of bacteria by monocytes was less than that by granulocytes. These resulcs strongJy suggest that production of ahemolysin is a means by which E. coli counteracrs the activity of phagocytes by injuring these cells with the toxin.}, subject = {Escherichia coli}, language = {en} } @article{KrallmannWenzelOttHackeretal.1989, author = {Krallmann-Wenzel, U. and Ott, M. and Hacker, J{\"o}rg and Schmidt, G}, title = {Chromosomal mapping of genes encoding mannose-sensitive (type I) and mannose-resistant F8(P) fimbriae of Escherichia coli O18:K5:H5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59545}, year = {1989}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} } @article{MunoaHackerJuarez1988, author = {Munoa, F. and Hacker, J{\"o}rg and Juarez, A.}, title = {Characterization of a chromosomal mutant that blocks hemolysin excretion in Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59534}, year = {1988}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} } @article{HackerUlmerFasskeetal.1987, author = {Hacker, J{\"o}rg and Ulmer, E. and Fasske, E. and Schmidt, G.}, title = {Isolation and characterization of coliphage Omega18A specific for Escherichia coli O18ac strains}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73001}, year = {1987}, abstract = {The bactedophage Q18A, specific for Escherichia coli 018ac srrains, was isolated frorn sewage. The results of host range and conjugation experiments showed that the sensitivity of bacteria to the phage is associated with rhe presence of 018ac antigens. With sorne of rhe 018 strains rhe phage Q18A produces clear Iysis on bacterial lawns only when applied at a high multiplicity and moreover the phage does not multiply. With rhe help of the phage Ql8A, E. coli 0 18ac strains could be divided inro rwo serologically clistinct subgroups called 018A and 018A1• E. coli strains belanging to the sugroup 0 ISAare sensitive to phage Q t8A wheteas bacteria of subgroup A1 are resistanr.}, subject = {Escherichia coli}, language = {en} } @article{SchmollHackerGoebel1987, author = {Schmoll, T. and Hacker, J{\"o}rg and Goebel, W.}, title = {Nucleotide sequence of the sfaA gene coding for the S fimbrial protein subunit of Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59480}, year = {1987}, abstract = {The sfaA gene of the uropathogenic Escherichia coli 06 strain 536, which is responsible for the determination of the S fimbrial protein subunit, was sequenced. The structural gene codes for a polypeptide of 180 amino acids including a 24-residue N-terminal signal sequence. A size of 15.95 kDa was calculated for the processed SfaA protein. The nucleotide and deduced amino acid sequences show significant homology to those of the F1C fimbria and, to a lesser extent, of the mannose- sensitive hemagglutinating fimbria (FimA, PilA). Only week homology toP fimbriae subunits (F72 , Pap) was found.}, subject = {Infektionsbiologie}, language = {en} } @article{HackerSchrettenbrunnerSchroeteretal.1986, author = {Hacker, J{\"o}rg and Schrettenbrunner, A. and Schr{\"o}ter, G. and Schmidt, G. and D{\"u}vel, H. and Goebel, W.}, title = {Characterization of Escherichia coli wild-type strains by means of agglutination with antisera raised against cloned P-, S- and MS-fimbriae antigens, hemagglutination, serotyping and hemolysin-production}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72992}, year = {1986}, abstract = {E. coli stcains isolated from patients with urinary tcact infecrions (UTn very often possess mannose"sensitive (MS) and mannose-resistant (MR) adherence facmrs (fimbriae). According to their receptor specificity the mannose-resistant adhesins can be divided inm several types, P, S, M and X. We have cloned rhe determinants of rhree groups of UTI E. coli adhesins, MS, p and S, and prepared specific aorisera against the fimbriae antigens. 189 hernagglutination (HA+) -positive stcains, 96 fecal isolates and 93 strains isoJated from UTI . have been tesred with rhese specific antisera and further characterized by receptor specific : HA, HA parteras and further of rhe "common 0 serogroups" 01, 02, 04, 06, 07, 08, 018, ' 025, 075, most prevalenr in UTI, and hemolysin production. · 68 (73 \%) of the UTI srrains a.nd 50 (52\%) of the fecal isolates showed P-receptor specificiry; 16 (17\%) of the uropathogenic bacteria and 33 (34\%) of the fecal strains exhibited S, M or X-fimbriae antigens. 24\% of rhe P-hemagglutinating (P+) strains reacted wirb P (F8)-specific antiserum. In contrast, more than three quaner of the s+-srrains were agglutinated by S-specific antiserum. HA-pattern VJ and 018 amigen were found to be associared with P-fimbriae strains, wbereas HA-pattern V and VII and the 0 anrigens 02 (M-type), 06 and 018 (5-type) occurred most frequently in p- -strains. A high percentage of P-fimbriated strains showed mannose-sensitive hemagglurination and hemolysin production.}, subject = {Escherichia coli}, language = {en} } @article{HackerOttSchmidtetal.1986, author = {Hacker, J{\"o}rg and Ott, M. and Schmidt, G. and Hull, R. and Goebel, W.}, title = {Molecular cloning of the F8 fimbrial antigen from Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59391}, year = {1986}, abstract = {The genetic determinant coding for the Pspecific F8 fimbriae was cloned from · the chromosome of the Escherichia coli wild-type strain 2980 (018: K5: H5: FlC, F8). The F8 determinant was further subcloned into the Pstl site of pBR322 and a restriction map was established. In a Southern hybridization experiment identity between the chromosomally encoded F8 determinant of 2980 and its cloned Counterpart was demonstrated. The cloned F8 fimbri{\"a}e and those of the wild type strain consist of a protein subunit of nearly 20 kDa. F8 fimbriated strains were agglutinated by an F8 polyclonal antiserum, caused mannose-resistant hemagglutination and attached to human uroepi thellal cells. The cloned F8 determinant was weil expressed in a variety of host strains.}, subject = {Infektionsbiologie}, language = {en} }