TY - JOUR A1 - Schneider, György A1 - Dobrindt, Ulrich A1 - Middendorf, Barbara A1 - Hochhut, Bianca A1 - Szijártó, Valeria A1 - Emódy, Levente A1 - Hacker, Jörg T1 - Mobilisation and remobilisation of a large archetypal pathogenicity island of uropathogenic \(Escherichia\) \(coli\) \(in\) \(vitro\) support the role of conjugation for horizontal transfer of genomic islands JF - BMC Microbiology N2 - Background: A substantial amount of data has been accumulated supporting the important role of genomic islands (GEIs) - including pathogenicity islands (PAIs) - in bacterial genome plasticity and the evolution of bacterial pathogens. Their instability and the high level sequence similarity of different (partial) islands suggest an exchange of PAIs between strains of the same or even different bacterial species by horizontal gene transfer (HGT). Transfer events of archetypal large genomic islands of enterobacteria which often lack genes required for mobilisation or transfer have been rarely investigated so far. Results: To study mobilisation of such large genomic regions in prototypic uropathogenic E. coli (UPEC) strain 536, PAI II(536) was supplemented with the mob(RP4) region, an origin of replication (oriV(R6K)), an origin of transfer (oriT(RP4)) and a chloramphenicol resistance selection marker. In the presence of helper plasmid RP4, conjugative transfer of the 107-kb PAI II(536) construct occured from strain 536 into an E. coli K-12 recipient. In transconjugants, PAI II(536) existed either as a cytoplasmic circular intermediate (CI) or integrated site-specifically into the recipient's chromosome at the leuX tRNA gene. This locus is the chromosomal integration site of PAI II(536) in UPEC strain 536. From the E. coli K-12 recipient, the chromosomal PAI II(536) construct as well as the CIs could be successfully remobilised and inserted into leuX in a PAI II(536) deletion mutant of E. coli 536. Conclusions: Our results corroborate that mobilisation and conjugal transfer may contribute to evolution of bacterial pathogens through horizontal transfer of large chromosomal regions such as PAIs. Stabilisation of these mobile genetic elements in the bacterial chromosome result from selective loss of mobilisation and transfer functions of genomic islands. KW - Recombination directionality factor KW - Staphylococcus-aureus KW - Yersinia-pseudotuberculosis KW - Pseudomonas-aeruginosa KW - Bacterial conjugation KW - Suicide vector KW - Gene-transfer KW - Excision KW - Family KW - Evolution Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-140975 VL - 11 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 - Zingler, G. A1 - Blum, G. A1 - Falkenhagen, U. A1 - Orskov, I. A1 - Orskov, F. A1 - Hacker, Jörg A1 - Ott, M T1 - Clonal differentiation of uropathogenic E. coli isolates of serotype O6:K5 by fimbrial antigen typing and DNA long-range mapping techniques N2 - Escherichia coli isolates of serotype 06: K5 are the most common causative agents of cystitis and pyelonephritis in adults. To answer the question, as to whether strains of this particular serotype represent one special clonal group, out of a collection of 34 serotype 06: K5 isolates [Zingler et al. ( 1990) Zentralbl. Bakteriol Mikrobiol Hyg [A] 274:372-381] 15 strains were selected andanalyzed in detail. The flagellar (H) antigen and the outer membrane protein (OMP) pattern were determined. Furtherserum resistance properties and the genetic presence and expression of other virulence factors, including hemolysin, aerobactin, P fimbriae, S/F1C fimbriae and type 1 fimbriae was evaluated. In~laddition the Xbalmacrorestriction pattern of ten representative isolates was elaborated and the fimbrial (F) antigentype ofthe P fimbriae was determined, to obtain the complete 0: K: H: F pattern. These analyses could clearly show that the 06: K5 isolates do not represent one clonal group. The Xbal-macrorestriction profiles were heterogeneaus and marked differences in the hybridization patterns, using virulenceassociated gene probes in Southern hybridization of long-range-separated genomic DNA, were observed among the strains. However, some of strains showed similarities in the genomic profiles, arguing for clonal groupings among the 06: K5 isolates. lnterstingly the strains grouped tagether exhibited the same fimbrial F typethat many indicate a coincidence of this phenotypic trait with clonality. KW - Infektionsbiologie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59865 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 - 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 - 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 - 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 - 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 - 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 - Ott, M. A1 - Bender, L. A1 - Lück, P. C. A1 - Meyer, P. A1 - Hacker, Jörg T1 - Distribution of Legionellae in a hospital water system: prevalence of immunologically and genetically related Legionella pneumophila serogroup 6 isolates N2 - A hospital warm water system was monitored for the prcsence and distribution of lcgionellac. Subtyping of ten scletled Legionella pneumophiltl isolates. originating from four different sites in the system by using serogroup spccific antisera in an indircct immunofluorcscence tcst, rcvcalcd that nine of the tcn isolatcs belonged to scrogroup 6, while the remaining one was serogroup I 0. Two monoclonal antibodics (mAbs) spccific for a subgroup of serogroup 6 strains were further used for characterization. None of the strains reactcd with these mAbs. Genome analysis by elaborating Not I profiles using the pulscd field gel electrophoresis (PFGE) technique revealed that nearly all serogroup 6 isolates dcrived from different sites, including a new building connected hy a ring pipe. wcrc identical according to restriction fragment pattems. The patterns were distinguishable from those of the two L. pnewnophi/a serogroup 6 rcfcrencc strains, and ftom that of thc L. pneumophila scrogroup 10 isolate. These data arguc for a relatively homogeneaus L. pneunwpltila serogroup 6 population in the entire watcr system. KW - Infektionsbiologie KW - Legionella pneumophila KW - Hospital water system KW - Environmental isolate KW - Serogroup KW - Genomic profile Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59827 ER - TY - JOUR A1 - Schroten, H. A1 - Steinig, M. A1 - Plogmann, R. A1 - Hanisch, F. G. A1 - Hacker, Jörg A1 - Herzig, P. A1 - Wahn, V T1 - S-fimbriae mediated adhesin of Escherichia coli to human buccal epithelial cells is age independent N2 - S-fimbriated Escherichia coli, which cause sepsis and meningitis in the newbom, bind to sialic acid-containing glycoprotein structures on the surface of human buccal epithelial cells. The dependence of · this binding on host age was examined. S-fimbriated · E. coli adhered in comparable numbers to cells in newborns, infants, children and adults (23.0 ± 8.6; 23.1 ± 11.5; 24.7 ± 7.9; 28.9 ± 8.8). Thus, the increased susceptibility of neonates to infections caused by S-fimbriated E. coli cannot be explained by enhanced · adhesion to epithelial cells N2 - Die S-Fimbrien vermittelte Adhiision von Escherichia coli an menschliche Mundschleimhautzellen ist altersunabhängig. S-Fimbrien tragende Escherichia coli, die Sepsis und Meningitis . im Neugeborenenalter verursachen, binden an sialinsäurehaltige Glycoproteine atif der Oberfläche menschlicher Mundschleimhautzellen. Wir untersuchten die Abhängigkeit · der Bindung vom Alter des Schleimhautzellenspenders. S-Fimbrien tragende. E. coli banden in vergleichbarer Zahl an Zellen von Neugeborenen, Säuglingen, älteren · Kindern und Erwachsenen (23,0 ± 8,6; 23,1 ± 11,5; 24,7 ± 7,9; 28,9 ± 8,8). Die vermehrte Empfänglichkeit von Neugeborenen für Infektionen, die durch S- Fimbrien tragende E. coli verursacht werden, kann nicht mit einer verstärkten Adhäsion an Mundschleimhautzellen erklärt wer.den. KW - Infektionsbiologie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59830 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 - Schroten, H. A1 - Hanisch, F. G. A1 - Plogmann, R. A1 - Hacker, Jörg A1 - Uhlenbruck, G. A1 - Wahn, V. T1 - Inhibition of Adhesion of S-fimbriated Escherichia coli to buccal epithelial cells by human milk fat globule membrane components: a novel aspect of protective function of mucins in the non-immunoglobulin fraction N2 - We investigated the presence of factors in human milkthat inhibit Invasion of pathogenic bacteria. The efl'ect of human milk fat globule membrane (HMFGM) components on adhesion of cloned S-fimbriated Escherichia coli to human buccal epithelial cells was analyzed. S fimbriae are a common feature of E. coli strains causing sepsis and meningitis in newborns and are bound to epithelia via sialyl-(a-2-3)galactoside structures. Human milk fat globules (HMFG) could be agglutinated by the above-mentioned bacteria. Agglutination could be inhibited by fetuin, human glycophorin, and a 1-acid glycoprotein. In addition, pretreatment of HMFG with Jlibrio cholerae neuraminidase markedly reduced bacterium-induced agglutinations, indicating the involvement of neuraminic acid-containing glycoproteins. In contrast, Iipid droplets of infant formula or artificiallipid emulsions (Intralipid) could not be agglutinated. HMFG were present in stools of breast-fed neonates as shown by indirect immunofluorescence staining with a monoclonal antibody directed against carbohydrate residues present on HMFGM. These HMFG could be agglutinated by bacteria. HMFG inhibited E. coli adhesion to buccal epithelial cells. To further characterize relevant E. coli binding structures, HMFGM components w~re separated by gel chromatography. The mucin fraction showed the most pronounced inhibitory efrect on adhesion of S-fimbriated E. coli to human buccal epithelial cells. Our data soggest that HMFG inhibit bacterial adhesion in the entire intestine and thereby may provide protection against bacterial infection. KW - Infektionsbiologie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59793 ER - TY - JOUR A1 - Zingler, G. A1 - Ott, M. A1 - Blum, G. A1 - Falkenhagen, U. A1 - Naumann, G. A1 - Sokolowska-Köhler, W. A1 - Hacker, Jörg T1 - Clonal analysis of Escherichia coli serotype O6 strains from urinary tract infections N2 - A total of 36 Escherichia coli urinary tract isolates (UTI) of serotype 06, with different combinations of capsule ( K) and flagellin ( H) antigens, were analysed according to the outer membrane pattern (OMP), serum resistance properties, mannose-resistant hemagglutination using various types of erythrocytes, and also for the genetic presence and the expression of Pfimbriae. S fimbriae/F1 C fimbriae, Type 1 fimbriae, aerobactin and hemolysin. Twenty selected strains were further analysed by pulsed field gel electrophoresis (PFGE), elaborating genomic profilas by Xba I cleavage and subsequent Southern hybridization to virulence-associated DNA probes. lt could be shown that 06 UTI isolates represent a highly heterogeneaus group of strains according to the occurrence and combination of these traits. Relatedness an the genetic and the phenotypic Ievei was found for some of the strains exhibiting the same 0: K: H: F serotype. DNA Iang-range mapping further indicated some interesting features, according to the copy number and the genomic linkage of virulence genes. KW - Infektionsbiologie KW - E. coli serotype 06 KW - urinary tract infection KW - virulence factors KW - clonal analysis KW - molecular epidemiology Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59786 ER - TY - JOUR A1 - Schroten, H. A1 - Lethen, A. A1 - Hanisch, F., G. A1 - Plogmann, R. A1 - Hacker, Jörg A1 - Nobis-Bosch, R. A1 - Wahn, V. T1 - 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 N2 - 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. KW - Infektionsbiologie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59804 ER - TY - JOUR A1 - Tschäpe, Helmut A1 - Bender, Larisa A1 - Ott, Manfred A1 - Wittig, Walter A1 - Hacker, Jörg T1 - Restriction fragments length polymorphism and virulence pattern of the veterinary pathogen Escherichia coli O139:K82:H1 N2 - Escherichia coli 0139: K82: H1 strains originating from outbreaks and single cases of oedema disease in pigs were characterized by their genomic restriction fragment length polymorphism (RFLP), their virulence pattern, and by the occurrence as well as the genomic distribution of the determinants for hemolysin (hly) and verotoxins (shiga-like toxins; sltI, sltII). Whereas the RFLPs revealed considerable variation among the E. coli 0139: K82: H1 isolates depending the origin and epidemic source of the strains, the virulence gene slt II was found to be present in nearly all strains in a particular chromosomal region. Similar to RFLPs, the plasmid profiles are useful for epidemiological analysis. KW - Escherichia coli Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86131 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 - 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 - Ott, M. A1 - Bender, L. A1 - Blum, G. A1 - Schmittroth, M. A1 - Achtmann, M. A1 - Tschäpe, H. A1 - Hacker, Jörg T1 - Virulence patterns and long range mapping of extraintestinal Escherichia coli K1, K5 and K100 isolates: Use of pulse field gel electrophoresis N2 - A total of 127 extraintestinal Escherichia coli strains of the capsule serotypes Kl, KS, and KlOO from human and animal sources were analyzed for DNA sequences specific for the genes for various adhesins (P fimbriae fpap] and P-related sequences fprs], S fimbriae [s/a)/FlC fimbriae [foc], and type I fimbriae lfim]), aerobactin (aer), and hemolysin (hly). The expression of corresponding virulence factors was also tested. Twenty-four selected strains were analyzed by long-range DNA mapping to evaluate their genetic relationships. DNA sequences for the adhesins were often found in strains not expressing them, while strains with hemolysin and aerobactin genes usually did express them. Different isolates of the same serotype orten expressed different virulence patterns. The use of virulence-associated gene probes for Southern hybridization with genomic DNA fragments separated by pulsed-field gel electrophoresis revealed that a highly heterogeneous restriction fragment length and hybridization pattern existed even within strains of the same serotype. Long-range DNA mapping is therefore useful for the evaluation of genetic relatedness among individual isolates and facilitates the performance of .precise molecular epidemiology. KW - Infektionsbiologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59738 ER - 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 -