@article{SchmollHoschuetzkyMorschhaeuseretal.1989, author = {Schmoll, T. and Hosch{\"u}tzky, H. and Morschh{\"a}user, J. and Lottspeich, F. and Jann, K. and Hacker, J{\"o}rg}, title = {Analysis of genes coding for the Sialic acid-binding adhesin and two other minor fimbrial subunits of the S-fimbrial adhesin determinant of Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59585}, year = {1989}, abstract = {The S flmbrial adhesln (Sfa) enables Esch richla colito attach to slalfc acld-containing receptor molecules of eukaryotJc cells. As prevlously reported, the genetlc determinant coding for the Sfa of an E. co/1 06 strain was cloned, the gene codlng for the major fimbrfal subunit was ldentlfled and sequenced and th.e S speclflc adhesin was detected. Here we present evidence that ln addltlon to the major subunit proteln SfaA three other minor subunit proteins, SfaG (17 kD), SfaS (14kD) and SfaH (31 kD) can be isolated from the S..speclfic flmbrial adhesln complex. The genes coding for these minor subunits were ldenblied, mutagenlzed separately and sequenced. Using haemagglutlnatton tests. electron-microscopy and quantitative ELISA assays with monoclonal anti-SfaA and anti-SfaS antlbodles the functlons of the minor subunlts were determined. lt was determlned that SfaS ls ldentlcal to the S-specific adhesln; whlch also plays a role ln deterrninatlon of the degree of fimbri· ation ofthe cell. The mlnor subunit SfaH also had some Jnfluence on the Ievei of fimbrlation of the cell. while StaG ls necessary for full expression of S·specific binding. lt was further shown that the amino-terminal proteln sequence of the isolated SfaS profein was identJcal to the proteln sequence calculated from the DNA sequence of the sfaS gene locus.}, subject = {Infektionsbiologie}, language = {en} } @article{LueckBenderOttetal.1991, author = {L{\"u}ck, P. Christian and Bender, Larisa and Ott, Manfred and Helbig, J{\"u}rgen H. and Hacker, J{\"o}rg}, title = {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}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40392}, year = {1991}, abstract = {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.}, language = {en} } @article{KnappThenWelsetal.1985, author = {Knapp, S. and Then, I. and Wels, W. and Michel, W. and Tsch{\"a}pe, H. and Hacker, J{\"o}rg and Goebel, W}, title = {Analysis of the flanking regions from different hemolysin determinants of Escherichia coli}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59374}, year = {1985}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} } @article{OttHackerSchmolletal.1986, author = {Ott, M. and Hacker, J{\"o}rg and Schmoll, T. and Jarchau, T. and Korhonen, T. K. and Goebel, W}, title = {Analysis of the genetic determinants coding for the S fimbrial adhesin (sfa) in different Escherichia coli strains causing meningitis or urinary tract infections}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59432}, year = {1986}, abstract = {Recently we have described the molecular cloning of the genetic determinant coding for the S-fimbrial adhesin (Sfa), a sialic acid-recognizing pilus frequently found among extraintestinal Eschenchili coli isolates. Fimbriae from the resulting Sfa + E. coli K-12 clone were isolated, and an Sfa-specific antiserum was prepared. Western blots indicate that S fimbriae isolated from different uropathogenic and meningitis-associated E. coli strains, including 083:Kl isolates, were serologically related. The Sfa-specific antibodies did not cross-react with P fimbriae, but did cross-react with FlC fimbriae. Furthermore the sja+ recombinant DNAs and some cloned s/a-flanking regions were used as probes in Southem experiments. Chromosomal DNAs isolated from 018:Kl and 083:Kl meningitis strains with and without S fimbriae and from uropathogenic 06:K + strains were hybridized against these sfa-specific probes. Only one copy of the sfa determinant was identified on the chromosome of these strains. No sfa-specific sequences were observed on the chromosome of E. coli K-12 strains and an 07:Kl isolate. With the exception of small alterations in the sfa-coding region the genetic determinants for S fimbriae were identical in uropathogenic 06:K + and meningitis 018:Kl and 083:Kl strains. The sfa determinant was also detected on the chromosome of Kl isolates with an Sfa-negative phenotype, and specific cross-hybridization signals were visible after blotting against FlC-specific DNA. In addition homology among the different strains was observed in the sfa-flanking regions.}, 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{HackerOttWintermeyeretal.1993, author = {Hacker, J{\"o}rg and Ott, Manfred and Wintermeyer, Eva and Ludwig, Birgit and Fischer, Gunter}, title = {Analysis of virulence factors of Legionella pneumophila.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70620}, year = {1993}, abstract = {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.}, subject = {Legionella pneumophila}, language = {en} } @article{SchefferKoenigHackeretal.1985, author = {Scheffer, J. and K{\"o}nig, W. and Hacker, J{\"o}rg and Goebel, W.}, title = {Bacterial adherence and hemolysin production from Escherichia coli induces histamine and leukotriene release from various cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59361}, year = {1985}, abstract = {We investigated the role of bacterial adherence and hemolysin production from Escherichia coli parent and genetically cloned strains as to their eft'ects on bistaJidne release from rat mast cells and leukotriene generation from human polymorphonuclear granulocytes. These mediators were involved in the induction of inftammatory disease processes and led, for example, to enhancement of vascular permeability, chemotaxis (leukotriene 84 [LTB4]), chemoaggregation, lysosomal enzyme release, and smooth muscle contraction, (LTC4, LTD4 , and LTE4). Washed bacteria (E. coli K-12 Ms+ my=; E. coli 536 Ms+ MR= my=) as weil as their culture supematants were analyzed. Washed E. coli K-12 (Hiy+), unlike Hly- strains, induced high amounts of histamine release from rat mast cells and chemotactic activity from human polymorphonuclear granulocytes. Significant leukotriene releasewas obtained with washed E. coli K-12 my+ strains and their bacterial culture supematants. Leukotriene induction was dependent on the amount of hemolysin activity present in the supematant. However, additional soluble factors should also be considered. The presence of hemolysin appeared to aceeierate and enhance the rate of phagocytosis of bacteria by neutrophUs. When E. coli 536 (MS+ MR= Hly=) strains were analyzed, the simultaneous presence of MR+ pili and hemolysin production led to an increase in histamine release as compared with MR- my+ strains. The genetically cloned MR+ my+ E. coli 536 strain induced higher amounts of IeukotrieDes as compared with the wUd-type strain. Our data soggest a potent role for adhesins and hemolysin as virulence factors in inducing the release of inftammatory mediators.}, subject = {Infektionsbiologie}, language = {en} } @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{KorhonenParkkinenHackeretal.1986, author = {Korhonen, T. K. and Parkkinen, J. and Hacker, J{\"o}rg and Finne, J. and Pere, A. and Rhen, M. and Holth{\"o}fer, H}, title = {Binding of Escherichia coli S fimbriae to human kidney epithelium}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59415}, year = {1986}, abstract = {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.}, subject = {Infektionsbiologie}, language = {en} } @article{ParkkinenKorhonenPereetal.1988, author = {Parkkinen, J. and Korhonen, T. K. and Pere, A. and Hacker, J{\"o}rg and Soinila, S.}, title = {Binding sites in the rat brain for Escherichia coli S fimbriae associated with neontal meningitis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59500}, year = {1988}, abstract = {Escherichia coli strains that cause sepsis and meningitis in neonatal infants carry S fimbriae that bind to sialyl galactoside units of cell surface glycoproteins. To investigate the possible role of S fimbriae in determining the tissue tropism of neonatal menlngitis, we have studied the preselice of binding sites for S fimbriae in different tissues of the neonatal rat which is susceptible to meningitis caused by S-fimbriated E. coli. Purified S fimbriae were incubated on cryostat sections of different rat oipns and their bindina was assessed by indirect immunofluorescence. In the bnin of the neonatal rat, S fimbriae specifically bound to the luminal surfaces of the vascular endothelium and of the epithelium lining the choroid plexuses and bnin ventricles. The · bindlog W.s completely inhibited by the trisaccharide NeuAca2-3Ga)ßl-4Gic, a receptor analogue of S fimbriae, and by a preceding neuraminidase treatment of the sections. A recombinant E. coli strain expressina S fimbriae adhered in large numbers to the same tissue sites in the neonatal brain sections as did the purified fimbriae, · whereas the nonfimbriated host strahi and a recombiiuuit strain expresslog P fi.mbriae did not adhere to brain tissues. The results soggest that adhesion of S-fimbriated bacteria to the binding sites observed in the neonatai bnin has a pathogenetic roJe durlog bacterial Invasion from cii'culation into the cerebrospinal fluid.}, subject = {Infektionsbiologie}, language = {en} }