The genus Listeria contains the two pathogenic species Listeria monocytogenes and Listeria ivanov... more The genus Listeria contains the two pathogenic species Listeria monocytogenes and Listeria ivanovii and the four apparently apathogenic species Listeria innocua, Listeria seeligeri, Listeria welshimeri, and Listeria grayi. Pathogenicity of the former two species is enabled by an approximately 9kb virulence gene cluster which is also present in a modified form in L. seeligeri. For all Listeria species, the sequence
8io2entrum) der Universität Würzburg, Lehrstuhl Mikrobiologie, Am Hubland 0·97074, Wurzburg. erma... more 8io2entrum) der Universität Würzburg, Lehrstuhl Mikrobiologie, Am Hubland 0·97074, Wurzburg. ermany. pecl J L lvanovll and . t. rnonocytcg nes c n dlffer ntlated bt hernt· oally and how different ho t r-ange • Vlrulence of L monocytogenes I eiependent on. th lntegr ty of prlA whlch po IOvety and co-o dlt1etely r ula anscription of veral vlrufence gene Un ' I now, prfA homologue had not been ldentlfled ln b.. IVIIInovll. W have now clo ed a chromo omal eglon from L. lvsnov/1 comprl lng two genea wHh filgh , omoJogy to th plcA and ptfA gene from L. monocytoge . Dfstal rom prtA, . an open r acJ.. iog frame hlghly homologaus to a phoephortbosyl Ryropho phate syntheta e gene (pr. ~ was newly d ntJfted. d flnlng the border of the vlrulenc gen qlu ter Transcrlptlon ot th gene for fvanoly ln 0 a,nd exp e lo of oth r enes of the viru ence gen Iu tet in L.. lvsnov/1 w r de ndent on PrtA. Th attem of ertA~pendent erotelne (PdP ) expras I L. lvsnovll waa lmllar, but not ldenttcal o thal ot L~ monocytogenes Th PrtA protelns. a . prelcted from nucleotJde • quences of bOth pathogenlc Qtrterla pecle ar very slmilar and alto algnlffcant homology to th · Crp-Fnr famlly of g ob I tran crlptlon r ufators. he two pathogenic Usterla species (L. ivanoilil and L. monocytogenes) are facultattve lntracellutar bacteria,
Several large, cell wall-associated internalins and one small, secreted internalin (InlC) have be... more Several large, cell wall-associated internalins and one small, secreted internalin (InlC) have been described previously in Listeria monocytogenes. Using degenerate primers derived from sequenced peptides of an L. ivanovii major secreted protein, we identified a new 4.25 kb internalin locus of L. ivanovii, termed i-inl FE. The two proteins encoded by this locus, i-InlE and i-InlF, belong to the group of small, secreted internalins. Southern blot analyses show that the i-inl FE locus does not occur in L. monocytogenes. These data also indicate that six genes encoding small, secreted internalins are present in L. ivanovii, in contrast to L. monocytogenes, in which inl C encodes the only small internalin. The mature i-InlE protein (198 amino acids) is secreted in large amounts into the brain-heart infusion (BHI) culture medium in the stationary growth phase. In minimum essential medium (MEM), which has been used previously to induce
Glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and... more Glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and plays a key role in protecting cells against oxygen toxicity. Until now, glutathione synthesis was thought to occur solely through the consecutive action of two physically separate enzymes, ␥-glutamylcysteine ligase and glutathione synthetase. In this report we demonstrate that Listeria monocytogenes contains a novel multidomain protein (termed GshF) that carries out complete synthesis of glutathione. Evidence for this comes from experiments which showed that in vitro recombinant GshF directs the formation of glutathione from its constituent amino acids and the in vivo effect of a mutation in GshF that abolishes glutathione synthesis, results in accumulation of the intermediate ␥-glutamylcysteine, and causes hypersensitivity to oxidative agents. We identified GshF orthologs, consisting of a ␥-glutamylcysteine ligase (GshA) domain fused to an ATP-grasp domain, in 20 gram-positive and gram-negative bacteria. Remarkably, 95% of these bacteria are mammalian pathogens. A plausible origin for GshF-dependent glutathione biosynthesis in these bacteria was the recruitment by a GshA ancestor gene of an ATP-grasp gene and the subsequent spread of the fusion gene between mammalian hosts, most likely by horizontal gene transfer.
Background: In the environment as well as in the vertebrate intestine, Listeriae have access to c... more Background: In the environment as well as in the vertebrate intestine, Listeriae have access to complex carbohydrates like maltodextrins. Bacterial exploitation of such compounds requires specific uptake and utilization systems.
We present the complete genome sequence of Listeria welshimeri, a nonpathogenic member of the gen... more We present the complete genome sequence of Listeria welshimeri, a nonpathogenic member of the genus Listeria. Listeria welshimeri harbors a circular chromosome of 2,814,130 bp with 2,780 open reading frames. Comparative genomic analysis of chromosomal regions between L. welshimeri, Listeria innocua, and Listeria monocytogenes shows strong overall conservation of synteny, with the exception of the translocation of an F o F 1 ATP synthase. The smaller size of the L. welshimeri genome is the result of deletions in all of the genes involved in virulence and of "fitness" genes required for intracellular survival, transcription factors, and LPXTG-and LRR-containing proteins as well as 55 genes involved in carbohydrate transport and metabolism. In total, 482 genes are absent from L. welshimeri relative to L. monocytogenes. Of these, 249 deletions are commonly absent in both L. welshimeri and L. innocua, suggesting similar genome evolutionary paths from an ancestor. We also identified 311 genes specific to L. welshimeri that are absent in the other two species, indicating gene expansion in L. welshimeri, including horizontal gene transfer. The species L. welshimeri appears to have been derived from early evolutionary events and an ancestor more compact than L. monocytogenes that led to the emergence of nonpathogenic Listeria spp.
Listeria monocytogenes (Sv4b) and Listeria ivanovii were pu-. rified to homogeneity. The N-termin... more Listeria monocytogenes (Sv4b) and Listeria ivanovii were pu-. rified to homogeneity. The N-terminal amino acid sequences of the 58 kDa Iisteriolysin of L. ivanovii and of a 24 k.Da protein which may ~epresent the CAMP-factor of L. ivanovii were determhied. Antibodies raised against the L. ivanovii Iisteriolysin and anti-streptolysin 0 antibodies were used in Western blot analyses to detect listeriolysin(s) in virulent and avirulent Listeria strains. It was found that all virulent strains of L. monocytogenes synthesize and secrete Iisteriolysin (Mr 58-59 kDa), albeit in significantly variable quantities. No protein cross-reaction with anti-listeriolysin antibodies or anti-streptolysin 0-antibodies was present in the s~pematant of List~ria innocua, Listeria welshimeri,. Listeria grayi and Listeria murrayi strains. Furthermore, the avirulent but liemolytic Listeria seeligeri did not cross-react with these antibodies. In a L. monocytogenes (strain EGD) gene bank constructed in Escherichia coli two types of hemol}rtic clones were identified. The first type carried recombinant plasmids with a common 2.0 kb fragment coding for a 23 kDa protein. This hemolytic activity was not activated by DTI and the 23 kDa protein . did not cross react with anti-listeriolysin or anti-Zusammenfassung: Hämolysin von Listerlen -Biochemie, Genetik und Funktion in der Pathogenese. SH-aktivierbare Hämolysine (Cytolysine) aus Listeria monocytogenes (Sv4b) und Listeria ivanovii wurden zur Homogenität gereinigt. Die N-terminalen Aminosäuresequenzen des 58 kDa großen Listeriolysins aus L. ivanovii und eines 24 kDa Protein, das vermutlich der CAMP-Faktor von L. ivanovii ist, wurden bestimmt. Mit Hilfe von Antikörpern gegen Listeriolysin aus · L: ivanovii und Streptolysin o·wurden im Western Blot virulente und aviruiente Listerlenstämme auf ihre Fähigkeit, Listeriolysin zu bilden, getestet. Danach synthetisieren und scheiden alle virulenten Stämme von L. monocytogenes Listeriolysin (Mr. 5S:59 kDa) aus, allerdings in sehr· unterschiedlicher Menge. In den Kulturüberständen von Listeria innocua, Listeria welshimeri, Listeria grayi und Listeria murrayi konnte kein mit Listerio Iysin-oder Streptolysin-0-Antikörpern kreUzreagierendes Protein nachgewiesen werden.
We report the complete and annotated genome sequence of the nonpathogenic Listeria seeligeri SLCC... more We report the complete and annotated genome sequence of the nonpathogenic Listeria seeligeri SLCC3954 serovar 1/2b type strain harboring the smallest completely sequenced genome of the genus Listeria.
The genus Listeria contains the two pathogenic species Listeria monocytogenes and Listeria ivanov... more The genus Listeria contains the two pathogenic species Listeria monocytogenes and Listeria ivanovii and the four apparently apathogenic species Listeria innocua, Listeria seeligeri, Listeria welshimeri, and Listeria grayi. Pathogenicity of the former two species is enabled by an approximately 9kb virulence gene cluster which is also present in a modified form in L. seeligeri. For all Listeria species, the sequence
8io2entrum) der Universität Würzburg, Lehrstuhl Mikrobiologie, Am Hubland 0·97074, Wurzburg. erma... more 8io2entrum) der Universität Würzburg, Lehrstuhl Mikrobiologie, Am Hubland 0·97074, Wurzburg. ermany. pecl J L lvanovll and . t. rnonocytcg nes c n dlffer ntlated bt hernt· oally and how different ho t r-ange • Vlrulence of L monocytogenes I eiependent on. th lntegr ty of prlA whlch po IOvety and co-o dlt1etely r ula anscription of veral vlrufence gene Un ' I now, prfA homologue had not been ldentlfled ln b.. IVIIInovll. W have now clo ed a chromo omal eglon from L. lvsnov/1 comprl lng two genea wHh filgh , omoJogy to th plcA and ptfA gene from L. monocytoge . Dfstal rom prtA, . an open r acJ.. iog frame hlghly homologaus to a phoephortbosyl Ryropho phate syntheta e gene (pr. ~ was newly d ntJfted. d flnlng the border of the vlrulenc gen qlu ter Transcrlptlon ot th gene for fvanoly ln 0 a,nd exp e lo of oth r enes of the viru ence gen Iu tet in L.. lvsnov/1 w r de ndent on PrtA. Th attem of ertA~pendent erotelne (PdP ) expras I L. lvsnovll waa lmllar, but not ldenttcal o thal ot L~ monocytogenes Th PrtA protelns. a . prelcted from nucleotJde • quences of bOth pathogenlc Qtrterla pecle ar very slmilar and alto algnlffcant homology to th · Crp-Fnr famlly of g ob I tran crlptlon r ufators. he two pathogenic Usterla species (L. ivanoilil and L. monocytogenes) are facultattve lntracellutar bacteria,
Several large, cell wall-associated internalins and one small, secreted internalin (InlC) have be... more Several large, cell wall-associated internalins and one small, secreted internalin (InlC) have been described previously in Listeria monocytogenes. Using degenerate primers derived from sequenced peptides of an L. ivanovii major secreted protein, we identified a new 4.25 kb internalin locus of L. ivanovii, termed i-inl FE. The two proteins encoded by this locus, i-InlE and i-InlF, belong to the group of small, secreted internalins. Southern blot analyses show that the i-inl FE locus does not occur in L. monocytogenes. These data also indicate that six genes encoding small, secreted internalins are present in L. ivanovii, in contrast to L. monocytogenes, in which inl C encodes the only small internalin. The mature i-InlE protein (198 amino acids) is secreted in large amounts into the brain-heart infusion (BHI) culture medium in the stationary growth phase. In minimum essential medium (MEM), which has been used previously to induce
Glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and... more Glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and plays a key role in protecting cells against oxygen toxicity. Until now, glutathione synthesis was thought to occur solely through the consecutive action of two physically separate enzymes, ␥-glutamylcysteine ligase and glutathione synthetase. In this report we demonstrate that Listeria monocytogenes contains a novel multidomain protein (termed GshF) that carries out complete synthesis of glutathione. Evidence for this comes from experiments which showed that in vitro recombinant GshF directs the formation of glutathione from its constituent amino acids and the in vivo effect of a mutation in GshF that abolishes glutathione synthesis, results in accumulation of the intermediate ␥-glutamylcysteine, and causes hypersensitivity to oxidative agents. We identified GshF orthologs, consisting of a ␥-glutamylcysteine ligase (GshA) domain fused to an ATP-grasp domain, in 20 gram-positive and gram-negative bacteria. Remarkably, 95% of these bacteria are mammalian pathogens. A plausible origin for GshF-dependent glutathione biosynthesis in these bacteria was the recruitment by a GshA ancestor gene of an ATP-grasp gene and the subsequent spread of the fusion gene between mammalian hosts, most likely by horizontal gene transfer.
Background: In the environment as well as in the vertebrate intestine, Listeriae have access to c... more Background: In the environment as well as in the vertebrate intestine, Listeriae have access to complex carbohydrates like maltodextrins. Bacterial exploitation of such compounds requires specific uptake and utilization systems.
We present the complete genome sequence of Listeria welshimeri, a nonpathogenic member of the gen... more We present the complete genome sequence of Listeria welshimeri, a nonpathogenic member of the genus Listeria. Listeria welshimeri harbors a circular chromosome of 2,814,130 bp with 2,780 open reading frames. Comparative genomic analysis of chromosomal regions between L. welshimeri, Listeria innocua, and Listeria monocytogenes shows strong overall conservation of synteny, with the exception of the translocation of an F o F 1 ATP synthase. The smaller size of the L. welshimeri genome is the result of deletions in all of the genes involved in virulence and of "fitness" genes required for intracellular survival, transcription factors, and LPXTG-and LRR-containing proteins as well as 55 genes involved in carbohydrate transport and metabolism. In total, 482 genes are absent from L. welshimeri relative to L. monocytogenes. Of these, 249 deletions are commonly absent in both L. welshimeri and L. innocua, suggesting similar genome evolutionary paths from an ancestor. We also identified 311 genes specific to L. welshimeri that are absent in the other two species, indicating gene expansion in L. welshimeri, including horizontal gene transfer. The species L. welshimeri appears to have been derived from early evolutionary events and an ancestor more compact than L. monocytogenes that led to the emergence of nonpathogenic Listeria spp.
Listeria monocytogenes (Sv4b) and Listeria ivanovii were pu-. rified to homogeneity. The N-termin... more Listeria monocytogenes (Sv4b) and Listeria ivanovii were pu-. rified to homogeneity. The N-terminal amino acid sequences of the 58 kDa Iisteriolysin of L. ivanovii and of a 24 k.Da protein which may ~epresent the CAMP-factor of L. ivanovii were determhied. Antibodies raised against the L. ivanovii Iisteriolysin and anti-streptolysin 0 antibodies were used in Western blot analyses to detect listeriolysin(s) in virulent and avirulent Listeria strains. It was found that all virulent strains of L. monocytogenes synthesize and secrete Iisteriolysin (Mr 58-59 kDa), albeit in significantly variable quantities. No protein cross-reaction with anti-listeriolysin antibodies or anti-streptolysin 0-antibodies was present in the s~pematant of List~ria innocua, Listeria welshimeri,. Listeria grayi and Listeria murrayi strains. Furthermore, the avirulent but liemolytic Listeria seeligeri did not cross-react with these antibodies. In a L. monocytogenes (strain EGD) gene bank constructed in Escherichia coli two types of hemol}rtic clones were identified. The first type carried recombinant plasmids with a common 2.0 kb fragment coding for a 23 kDa protein. This hemolytic activity was not activated by DTI and the 23 kDa protein . did not cross react with anti-listeriolysin or anti-Zusammenfassung: Hämolysin von Listerlen -Biochemie, Genetik und Funktion in der Pathogenese. SH-aktivierbare Hämolysine (Cytolysine) aus Listeria monocytogenes (Sv4b) und Listeria ivanovii wurden zur Homogenität gereinigt. Die N-terminalen Aminosäuresequenzen des 58 kDa großen Listeriolysins aus L. ivanovii und eines 24 kDa Protein, das vermutlich der CAMP-Faktor von L. ivanovii ist, wurden bestimmt. Mit Hilfe von Antikörpern gegen Listeriolysin aus · L: ivanovii und Streptolysin o·wurden im Western Blot virulente und aviruiente Listerlenstämme auf ihre Fähigkeit, Listeriolysin zu bilden, getestet. Danach synthetisieren und scheiden alle virulenten Stämme von L. monocytogenes Listeriolysin (Mr. 5S:59 kDa) aus, allerdings in sehr· unterschiedlicher Menge. In den Kulturüberständen von Listeria innocua, Listeria welshimeri, Listeria grayi und Listeria murrayi konnte kein mit Listerio Iysin-oder Streptolysin-0-Antikörpern kreUzreagierendes Protein nachgewiesen werden.
We report the complete and annotated genome sequence of the nonpathogenic Listeria seeligeri SLCC... more We report the complete and annotated genome sequence of the nonpathogenic Listeria seeligeri SLCC3954 serovar 1/2b type strain harboring the smallest completely sequenced genome of the genus Listeria.
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Papers by J. Kreft