@article{SchrotenLethenHanischetal.1992, author = {Schroten, H. and Lethen, A. and Hanisch, F., G. and Plogmann, R. and Hacker, J{\"o}rg and Nobis-Bosch, R. and Wahn, V.}, title = {Inhibition of adhesion of S-fimbriated Escherichia coli to epithelial cells by meconium feces of breast fed and formula fed newborns - mucins are the major inhibitor component}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59804}, year = {1992}, abstract = {We investigated the ability of meconium, feces from human milk-fed (HMF) newborns, and feces from formula-fed (FF) newborns to inhibit adhesion of S-fimbriated E. coli to human buccal epithelial cells. S-fimbriae are a common property of E.·coli strains causing sepsis and meningitis in neonates. Meconium had the highest content of neuraminic acid and the strongest inhibitory effect on bacterial adhesion. HMF also exerted high inhibitory activity while FF was markedly less active: To achieve inhibitory effects comparable to HMF a sixfold amount of FF was required. Glycoproteins from excretions were separated by gel chromatography. Fractions obtained were analyzed for adhesion-inhibiting activity. In all excretions analyzed, the mucin-containing fraction could be identified as the major inhibitory component. Inhibition was probably mediated by specific interaction of this fraction with S-fimbriae, as shown by binding of isolated fimbriae on Western blots after electrophoretic separation of glycoproteins. In conclusion, our data support the view that the mucin-containing fraction from meconium and human milk exerts antibacterial functions by preventing adhesin-mediated binding of pathogenic bacteria to mucosal epithelia. Key Words: S-fimbriated E. coli-Inhibition of adhesion-Meconium- Feces of human milk-fed newborns-Feces of formula-fed newborns-Mucins.}, 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{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{MarreHackerWoodetal.1989, author = {Marre, R. and Hacker, J{\"o}rg and Wood, G. and Schmidt, G.}, title = {Oral vaccination of rats with live avirulent Salmonella derivatives expressing adhesive fimbrial agents of uropathogenic Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59559}, year = {1989}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} } @article{KoenigKoenigSchefferetal.1989, author = {K{\"o}nig, W. and K{\"o}nig, B. and Scheffer, J. and Hacker, J{\"o}rg and Goebel, W.}, title = {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}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59564}, year = {1989}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} } @article{OttBenderMarreetal.1991, author = {Ott, M. and Bender, L. and Marre, R. and Hacker, J{\"o}rg}, title = {Pulsed field electrophoresis of genomic restriction fragments for the detection of nosocomial Legionella pneumophila in hospital water supplies}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59672}, year = {1991}, abstract = {Ten Legionella pneumophUa strains isolated from dift'erent sources were analyzed according to their restriction fragment patterils obtained by cle~vage of gen.omic DNA With Notl and Sftl and separation by pulsed field electrophoresis. Three L. pneumophila isolate~ from a nosocomial outbreak in L{\"u}~k (Germany) and three other L. prreumophilll stralns independently isolated from a water tap located in the care unit where tbe patients were bospitalized 'xhibited identical restricti9n fragment profiles. Therefore, we concluded that these environment81 spee~ens were the source of the Legionnatres dlsease. Anotber two isolates from patients and two strains from the environment, all unrelated to the outJlreak described, sbowed different cleavage patterns.}, subject = {Infektionsbiologie}, language = {en} } @article{HackerOttLudwigetal.1991, author = {Hacker, J{\"o}rg and Ott, M. and Ludwig, B. and Rdest, U.}, title = {Intracellular survival and expression of virulence determinants of Legionella pneumophila}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59681}, year = {1991}, abstract = {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: Intrazellul{\"a}res {\"U}berleben}, subject = {Infektionsbiologie}, language = {en} } @article{OttHacker1991, author = {Ott, M. and Hacker, J{\"o}rg}, title = {Analysis of the variability of S fimbriae expression in an Escherichia coli pathogen.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59695}, year = {1991}, abstract = {The uropathogenic Escherichia coli wiJd..:type strain 536 produces S-fimbriae, P-related fimbriae and type I fimbriae. Using immuno-colony dot and ELISA techniques, variants were detected showing an increased degree of S-fimbrial production. It was demonstrated by itrtmunofluorescence microscopy that in noimal (wild-type) and hyperS- fimbriated E. coli populaiions non-fimbriated cells also · exist, and that the percentage of Sfinibrlated and non-fimbriated bacteria was roughly identica1 in either population. Hyper-Sfimbriated variants could be stably maintained. The transition from wild-type to hyper-S-fimbriation, which occurs spontaneously, is markedly higher than vice versa. Southern blot analysis of the S fimbrial adhesin (sfa) determinants of normal and hyper-fimbriated strains revealed no marked difference in the gene structure.}, subject = {Infektionsbiologie}, language = {en} } @article{WintermeyerRdestLudwigetal.1991, author = {Wintermeyer, E. and Rdest, U. and Ludwig, B. and Debes, A. and Hacker, J{\"o}rg}, title = {Characterization of legiolysin (lly); responsible for hemolytic activity, colour production and fluorescence of Legionella pneumophila}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59706}, year = {1991}, abstract = {No abstract available}, subject = {Infektionsbiologie}, language = {en} } @article{BlumOttCrossetal.1991, author = {Blum, G. and Ott, M. and Cross, A. and Hacker, J{\"o}rg}, title = {Virulence determinants of Escherichia coli O6 extraintestinal isolates analysed by Southern hybridizations and DNA long range mapping techniques}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59717}, year = {1991}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} }