Mark Achtman

Horizontal versus familial transmission of Helicobacter pylori (2008)

Schwarz, Sandra, Morelli, Giovanna, Manica, Andrea, Balloux, Francois, Owen, Robert J., Graham, David Y., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Horizontal versus familial transmission of Helicobacter pylori (2008)

Schwarz, Sandra, Morelli, Giovanna, Manica, Andrea, Balloux, Francois, Owen, Robert J., Graham, David Y., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Horizontal versus Familial Transmission of Helicobacter pylori (2008)

Schwarz, Sandra, Morelli, Giovanna, Kusecek, Barica, Manica, Andrea, Balloux, Francois, Owen, Robert J., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Ceftriaxone-resistant Salmonella enterica serotype Newport, France (2008)

Egorova, Svetlana, Timinouni, Mohammed, Demartin, Marie, Granier, Sophie A., Whichard, Jean M., Sangal, Vartul, ...

The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 β-lactamase(Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during...

The rise and spread of a new pathogen: Seroresistant Moraxella catarrhalis (2007)

Wirth, Thierry, Morelli, Giovanna, Kusecek, Barica, Van Belkum, Alex, Van Der Schee, Cindy, Meyer, Axel, ...

The nosocomial human pathogen Moraxella catarrhalis is one the most important agents of human respiratory tract infections. This species is composed of two distinct lineages, one of only moderate...

Clonal Waves of Neisseria Colonisation and Disease in the African Meningitis Belt: Eight- Year Longitudinal Study in Northern Ghana (2007)

Julia Leimkugel, Abraham Hodgson, Abudulai Adams Forgor, Valentin Pflüger, Jean-Pierre Dangy, Tom Smith, ...

BackgroundThe Kassena-Nankana District of northern Ghana lies in the African “meningitis belt” where epidemics of meningococcal meningitis have been reoccurring every eight to 12 years for the...

Meningococcal Genetic Variation Mechanisms Viewed through Comparative Analysis of Serogroup C Strain FAM18 (2007)

Stephen D. Bentley, George S. Vernikos, Carol Churcher, Claire Arrowsmith, Tracey Chillingworth, ...

The bacterium Neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and...

An African origin for the intimate association between humans and Helicobacter pylori (2007)

Linz, Bodo, Balloux, Francois, Moodley, Yoshan, Manica, Andrea, Liu, Hua, Roumagnac, Philippe, ...

Infection of the stomach by Helicobacter pylori is ubiquitous among humans. However, although H. pylori strains from different geographic areas are associated with clear phylogeographic...

An African origin for the intimate association between humans and Helicobacter pylori (2007)

Linz, Bodo, Balloux, Francois, Moodley, Yoshan, Manica, Andrea, Liu, Hua, Roumagnac, Philippe, ...

Infection of the stomach by Helicobacter pylori is ubiquitous among humans. However, although H. pylori strains from different geographic areas are associated with clear phylogeographic...

Clonal waves of Neisseria colonisation and disease in the African meningitis belt: Eight-year longitudinal study in northern Ghana (2007)

Leimkugel, Julia, Hodgson, Abraham, Forgor, Abudulai Adams, Pflüger, Valentin, Dangy, Jean-Pierre, Smith, Tom, ...

Background The Kassena-Nankana District of northern Ghana lies in the African “meningitis belt” where epidemics of meningococcal meningitis have been reoccurring every eight to 12 years for the...

Meningococcal genetic variation mechanisms viewed through comparative analysis of serogroup C strain FAM18 (2007)

Bentley, Stephen D., Vernikos, George S., Snyder, Lori A. S., Churcher, Carol, Arrowsmith, Claire, Chillingworth, Tracey, ...

The bacterium Neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and...

The rise and spread of a new pathogen: Seroresistant Moraxella catarrhalis (2007)

Wirth, Thierry, Morelli, Giovanna, Kusecek, Barica, Van Belkum, Alex, Van Der Schee, Cindy, Meyer, Axel, ...

The nosocomial human pathogen Moraxella catarrhalis is one the most important agents of human respiratory tract infections. This species is composed of two distinct lineages, one of only moderate...

A bimodal pattern of relatedness between the Salmonella Paratyphi A and Typhi genomes: Convergence or divergence by homologous recombination? (2007)

Didelot, Xavier, Achtman, Mark, Parkhill, Julian, Thomson, Nicholas R., Falush, Daniel

All Salmonella can cause disease but severe systemic infections are primarily caused by a few lineages. Paratyphi A and Typhi are the deadliest human restricted serovars, responsible for ∼600,000...

Comparative genomic view of mechanisms of variation in Neisseria meningitidis through sequencing and analysis of a third meningococcal genome from serogroup C strain FAM18 (2006)

Stephen D. Bentley, George Vernikos, Carol Churcher, Claire Arrowsmith, Tracey Chillingworth, ...

The bacterium, Neisseria meningitidis, is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and...

Who Ate Whom? Adaptive Helicobacter Genomic Changes That Accompanied a Host Jump from Early Humans to Large Felines (2006)

Mark Eppinger, Claudia Baar, Bodo Linz, Günter Raddatz, Christa Lanz, Heike Keller, ...

Helicobacter pylori infection of humans is so old that its population genetic structure reflects that of ancient human migrations. A closely related species, Helicobacter acinonychis, is specific for...

Who ate whom? Adaptive Helicobacter genomic changes that accompanied a host jump from early humans to large felines (2006)

Mark Eppinger, Claudia Baar, Bodo Linz, Günter Raddatz, Christa Lanz, Heike Keller, ...

Helicobacter pylori infection of humans is so old that the population genetic structure of H. pylori reflects ancient human migrations. A closely related species, Helicobacter acinonychis, is...

Who Ate Whom? Adaptive Helicobacter Genomic Changes That Accompanied a Host Jump from Early Humans to Large Felines (2006)

Eppinger, Mark, Baar, Claudia, Linz, Bodo, Raddatz, Günter, Lanz, Christa, Keller, Heike, ...

Helicobacter pylori infection of humans is so old that its population genetic structure reflects that of ancient human migrations. A closely related species, Helicobacter acinonychis, is specific for...

Sex and virulence in Escherichia coli: an evolutionary perspective (2006)

Wirth, Thierry, Falush, Daniel, Lan, Ruiting, Colles, Frances, Mensa, Patience, Wieler, Lothar H., ...

Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals...

A bimodal pattern of relatedness between the Salmonella Paratyphi A and Typhi genomes: Convergence or divergence by homologous recombination (2006)

Didelot, Xavier, Achtman, Mark, Parkhill, Julian, Thomson, Nicholas R., Falush, Daniel

All Salmonella can cause disease but severe systemic infections are primarily caused by a few lineages. Paratyphi A and Typhi are the deadliest human restricted serovars, responsible for ∼600,000...

Gain and Loss of Multiple Genes During the Evolution of Helicobacter pylori (2005)

Helga Gressmann, Bodo Linz, Rohit Ghai, Klaus-Peter Pleissner, Ralph Schlapbach, Yoshio Yamaoka, ...

Sequence diversity and gene content distinguish most isolates of Helicobacter pylori. Even greater sequence differences differentiate distinct populations of H. pylori from different continents, but...

Gain and loss of multiple genes during the evolution of Helicobacter pylori (2005)

Gressmann, Helga, Linz, Bodo, Ghai, Rohit, Pleissner, Klaus-Peter, Schlapbach, Ralph, Yamaoka, Yoshio, ...

Sequence diversity and gene content distinguish most isolates of Helicobacter pylori. Even greater sequence differences differentiate distinct populations of H. pylori from different continents, but...

Deciphering host migrations and origins by means of their microbes (2005)

Wirth, Thierry, Meyer, Axel, Achtman, Mark

Mitochondrial DNA and microsatellite sequences are powerful genetic markers for inferring the genealogy and the population genetic structure of animals but they have only limited resolution for...

Microevolution and history of the plague bacillus, Yersinia pestis (2004)

Achtman,Mark, Morelli,Giovanna, Zhu,Peixuan X., Wirth,Thierry, Diehl,Ines, Kusecek,Barica, ...

The association of historical plague pandemics with Yersinia pestis remains controversial, partly because the evolutionary history of this largely monomorphic bacterium was unknown. The...

Proteome analysis of Neisseria meningitidis serogroup A (2004)

Bernardini,Giulia, Renzone,Giovanni, Comanducci,Maurizio, Mini,Roberta, Arena,Simona, D'Ambrosio,Chiara, ...

Neisseria meningitidis is an encapsulated Gram-negative bacterium responsible for significant morbidity and mortality worldwide. Meningococci are opportunistic pathogens, carried in the nasopharynx...

Helicobacter pylori: recombination, population structure and human migrations (2004)

Suerbaum,Sebastian, Achtman,Mark

Helicobacter pylori shows extensive genetic diversity and variability due to frequent intraspecific recombination during mixed infection. In the last years, modern genetic and genomic technology as...

Distinguishing human ethnic groups by means of sequences from Heliclobacter pylori: Lessons from Ladakh (2004)

Wirth,Thierry, Wang,Xiaoyan, Linz,Bodo, Novick,Richard P., Lum,J. Koji, Blaser,Martin, ...

The history of mankind remains one of the most challenging fields of study. However, the emergence of anatomically modern humans has been so recent that only a few genetically informative...

Genetics of capsule O-acetylation in serogroup C, W-135 and Y meningococci (2004)

Claus,Heike, Borrow,Ray, Achtman,Mark, Morelli,Giovanna, Kantelberg,Carmen, Longworth,Emma, ...

Capsular polysaccharides of serogroup C, W-135 and Y meningococci were previously reported to be O-acetylated at the sialic acid residues. There is evidence that O-acetylation affects the...

Comparative analysis of the genome sequences of Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica (2003)

Parkhill,Julian, Sebaihia,Mohammed, Preston,Andrew, Murphy,Lee D., Thomson,Nicholas, Harris,David E., ...

Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica are closely related Gram-negative -proteobacteria that colonize the respiratory tracts of mammals. B. pertussis is a...

Traces of human migrations in Helicobacter pylori populations (2003)

Falush,Daniel, Wirth,Thierry, Linz,Bodo, Pritchard,Jonathan K., Stephens,Matthew, Kidd,Mark, ...

Helicobacter pylori, a chronic gastric pathogen of human beings, can be divided into seven populations and subpopulations with distinct geographical distributions. These modern populations derive...

Clonal groupings in serogroup X Neisseria meningitis (2002)

Gagneux,Sébastien, Wirth,Thierry, Hodgson,Abraham, Ehrhard,Ingrid, Morelli,Giovanna, Kriz,Paula, ...

The genetic diversity of 134 serogroup X Neisseria meningitis isolates from Africa, Europe, and North America was analyzed by multilocus sequence typing and pulsed-field gel electrophoresis. Although...

Crystal structure of the OpcA integral membrane adhesin from Neisseria meningitidis (2002)

Prince,Stephen M., Achtman,Mark, Derrick,Jeremy P.

OpcA is an integral outer membrane protein from Neisseria meningitidis, the causative agent of meningococcal meningitis and septicemia. It mediates the adhesion of N. meningitidis to epithelial and...

Prospective study of a serogroup X Neisseria meningitidis outbreak in northern Ghana (2002)

Gagneux,Sebastien P., Hodgson,Abraham, Smith,Tom A., Wirth,Thierry, Ehrhard,Ingrid, Morelli,Giovanna, ...

After an epidemic of serogroup A meningococcal meningitis in northern Ghana, a gradual disappearance of the epidemic strain was observed in a series of five 6-month carriage surveys of 37 randomly...

Recombination and mutation during long-term gastric colonization by Helicobacter pylori: Estimates of clock rates, recombination size, and minimal age (2001)

Falush,Daniel, Kraft,Christian, Taylor,Nancy S., Correa,Pelayo, Fox,James G., Achtman,Mark, ...

The bacterium Helicobacter pylori colonizes the gastric mucosa of half of the human population, resulting in chronic gastritis, ulcers, and cancer. We sequenced ten gene fragments from pairs of...

Microevolution and History of the Plague Bacillus, Yersinia pestis (1998)

Achtman, Mark, Morelli, Giovanna, Zhu, Peixuan, Wirth, Thierry, Diehl, Ines

The association of historical plague pandemics with Yersinia pestis remains controversial, partly because the evolutionary history of this largely monomorphic bacterium was unknown. The...

A genetic study of the F-factor. (1969)

Achtman, Mark.

Thesis (Ph. D. in Molecular Biology)--University of California, June 1969.

Multilocus sequence typing: A portable approach to the identification of clones within populations of pathogenic microorganisms

Maiden, Martin C. J., Bygraves, Jane A., Feil, Edward, Morelli, Giovanna, Russell, Joanne E., Urwin, Rachel, ...

Traditional and molecular typing schemes for the characterization of pathogenic microorganisms are poorly portable because they index variation that is difficult to compare among laboratories. To...

Free recombination within Helicobacter pylori

Suerbaum, Sebastian, Smith, John Maynard, Bapumia, Khairun, Morelli, Giovanna, Smith, Noel H., Kunstmann, Erdmute, ...

Sequences of three gene fragments (flaA, flaB, and vacA) from Helicobacter pylori strains isolated from patients in Germany, Canada, and South Africa were analyzed for diversity and for linkage...

Yersinia pestis, the cause of plague, is a recently emerged clone of Yersinia pseudotuberculosis

Achtman, Mark, Zurth, Kerstin, Morelli, Giovanna, Torrea, Gabriela, Guiyoule, Annie, Carniel, Elisabeth

Plague, one of the most devastating diseases of human history, is caused by Yersinia pestis. In this study, we analyzed the population genetic structure of Y. pestis and the two other pathogenic...

Fit genotypes and escape variants of subgroup III Neisseria meningitidis during three pandemics of epidemic meningitis

Zhu, Peixuan, Van Der Ende, Arie, Falush, Daniel, Brieske, Norbert, Morelli, Giovanna, Linz, Bodo, ...

The genetic variability at six polymorphic loci was examined within a global collection of 502 isolates of subgroup III, serogroup A Neisseria meningitidis. Nine “genoclouds” were identified,...

Recombination and mutation during long-term gastric colonization by Helicobacter pylori: Estimates of clock rates, recombination size, and minimal age

Falush, Daniel, Kraft, Christian, Taylor, Nancy S., Correa, Pelayo, Fox, James G., Achtman, Mark, ...

The bacterium Helicobacter pylori colonizes the gastric mucosa of half of the human population, resulting in chronic gastritis, ulcers, and cancer. We sequenced ten gene fragments from pairs of...

Functional Activities and Immunoglobulin Variable Regions of Human and Murine Monoclonal Antibodies Specific for the P1.7 PorA Protein Loop of Neisseria meningitidis†

Wang, Jianfu, Jarvis, Gary A., Achtman, Mark, Rosenqvist, Einar, Michaelsen, Terje E., Aase, Audun, ...

The meningococcal PorA protein is considered a promising vaccine candidate. Although much is understood regarding the structure of PorA proteins, little is known about the structure-function...

Molecular and Biological Analysis of Eight Genetic Islands That Distinguish Neisseria meningitidis from the Closely Related Pathogen Neisseria gonorrhoeae

Klee, Silke R., Nassif, Xavier, Kusecek, Barica, Merker, Petra, Beretti, Jean-Luc, Achtman, Mark, ...

The pathogenic species Neisseria meningitidis and Neisseria gonorrhoeae cause dramatically different diseases despite strong relatedness at the genetic and biochemical levels. N. meningitidis can...

Carcinoembryonic Antigen Family Receptor Specificity of Neisseria meningitidis Opa Variants Influences Adherence to and Invasion of Proinflammatory Cytokine-Activated Endothelial Cells

Muenzner, Petra, Dehio, Christoph, Fujiwara, Taku, Achtman, Mark, Meyer, Thomas F., Gray-Owen, Scott D.

The carcinoembryonic antigen (CEA) family member CEACAM1 (previously called biliary glycoprotein or CD66a) was previously shown to function as a receptor that can mediate the binding of Opa...

Randomly Amplified Polymorphic DNA Genotyping of Serogroup A Meningococci Yields Results Similar to Those Obtained by Multilocus Enzyme Electrophoresis and Reveals New Genotypes

Bart, Aldert, Schuurman, Ilse G. A., Achtman, Mark, Caugant, Dominique A., Dankert, Jacob, Van Der Ende, Arie

Randomly amplified polymorphic DNA (RAPD) genotyping was applied to one representative strain of each of the 84 electrophoretic types (ETs) of Neisseria meningitidis serogroup A previously defined by...

Necessity of Molecular Techniques To Distinguish between Neisseria meningitidis Strains Isolated from Patients with Meningococcal Disease and from Their Healthy Contacts

Vogel, Ulrich, Morelli, Giovanna, Zurth, Kerstin, Claus, Heike, Kriener, Eugen, Achtman, Mark, ...

Serogroup C strains of Neisseria meningitidis were isolated from a Germany patient with severe meningococcal disease after a trip to the Czech Republic. These strains (case isolates) were...

Sequence Diversity, Predicted Two-Dimensional Protein Structure, and Epitope Mapping of Neisserial Opa Proteins

Malorny, Burkhard, Morelli, Giovanna, Kusecek, Barica, Kolberg, Jan, Achtman, Mark

The sequence diversity of 45 Opa outer membrane proteins from Neisseria meningitidis, Neisseria gonorrhoeae, Neisseria sicca, and Neisseria flava indicates that horizontal genetic exchange of opa...

Crystal structure of the OpcA integral membrane adhesin from Neisseria meningitidis

Prince, Stephen M., Achtman, Mark, Derrick, Jeremy P.

OpcA is an integral outer membrane protein from Neisseria meningitidis, the causative agent of meningococcal meningitis and septicemia. It mediates the adhesion of N. meningitidis to epithelial and...

Conjugational Complementation Analysis of Transfer-Deficient Mutants of Flac in Escherichia coli

Achtman, Mark, Willetts, Neil, Clark, Alvin J.

A series of 102 transfer-deficient (tra−) mutants of Flac (84 of which have been previously described) were classified as carrying frameshift, amber, ochre, UGA, and nonsuppressible mutations....

Genetic Analysis of Transfer by the Escherichia coli Sex Factor F, Using P1 Transductional Complementation

Willetts, Neil, Achtman, Mark

P1 transduction has been used to perform a complementation analysis of a series of transfer-deficient mutants of Flac. The results define ten cistrons and are consistent with the results of a...

Beginning a Genetic Analysis of Conjugational Transfer Determined by the F Factor in Escherichia coli by Isolation and Characterization of Transfer-Deficient Mutants

Achtman, Mark, Willetts, Neil, Clark, Alvin J.

Eighty-four transfer-deficient mutants of Flac have been isolated; 27 of these bear amber mutations and 1 mutant is temperature-sensitive. All the mutants transfer between 10−2 and

traG protein of the F sex factor of Escherichia coli K-12 and its role in conjugation

Manning, Paul A., Morelli, Giovanna, Achtman, Mark

The traG protein of the F sex factor is an inner membrane protein with a molecular weight of 116,000. Mutants in traG (or in traN) are able to trigger conjugal DNA replication even though they cannot...

Distinguishing human ethnic groups by means of sequences from Helicobacter pylori: Lessons from Ladakh

Wirth, Thierry, Wang, Xiaoyan, Linz, Bodo, Novick, Richard P., Lum, J. Koji, Blaser, Martin, ...

The history of mankind remains one of the most challenging fields of study. However, the emergence of anatomically modern humans has been so recent that only a few genetically informative...

Fertility repression of F-like conjugative plasmids: Physical mapping of the R6-5 finO and finP cistrons and identification of the finO protein

Timmis, Kenneth N., Andrés, Isabel, Achtman, Mark

The locations of the fertility inhibition genes finO and finP of the F-like conjugative multiple antibiotic-resistance plasmid R6-5 have been determined. As found previously for that of the fertility...

Microevolution and history of the plague bacillus, Yersinia pestis

Achtman, Mark, Morelli, Giovanna, Zhu, Peixuan, Wirth, Thierry, Diehl, Ines, Kusecek, Barica, ...

The association of historical plague pandemics with Yersinia pestis remains controversial, partly because the evolutionary history of this largely monomorphic bacterium was unknown. The...

Gain and Loss of Multiple Genes During the Evolution of Helicobacter pylori

Gressmann, Helga, Linz, Bodo, Ghai, Rohit, Pleissner, Klaus-Peter, Schlapbach, Ralph, Yamaoka, Yoshio, ...

Sequence diversity and gene content distinguish most isolates of Helicobacter pylori. Even greater sequence differences differentiate distinct populations of H. pylori from different continents, but...

Who Ate Whom? Adaptive Helicobacter Genomic Changes That Accompanied a Host Jump from Early Humans to Large Felines

Eppinger, Mark, Baar, Claudia, Linz, Bodo, Raddatz, Günter, Lanz, Christa, Keller, Heike, ...

Helicobacter pylori infection of humans is so old that its population genetic structure reflects that of ancient human migrations. A closely related species, Helicobacter acinonychis, is specific for...

Sex and virulence in Escherichia coli: an evolutionary perspective

Wirth, Thierry, Falush, Daniel, Lan, Ruiting, Colles, Frances, Mensa, Patience, Wieler, Lothar H, ...

Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals...

Characterization of the Pilin Ortholog of the Helicobacter pylori Type IV cag Pathogenicity Apparatus, a Surface-Associated Protein Expressed during Infection†

Andrzejewska, Joanna, Lee, Sae Kyung, Olbermann, Patrick, Lotzing, Nina, Katzowitsch, Elena, Linz, Bodo, ...

The Helicobacter pylori cag pathogenicity island (cag PAI) encodes components of a type IV secretion system (T4SS) involved in host interaction and pathogenicity. Previously, seven cag PAI proteins...

Multilocus sequence typing: A portable approach to the identification of clones within populations of pathogenic microorganisms

Maiden, Martin C. J., Bygraves, Jane A., Feil, Edward, Morelli, Giovanna, Russell, Joanne E., Urwin, Rachel, ...

Traditional and molecular typing schemes for the characterization of pathogenic microorganisms are poorly portable because they index variation that is difficult to compare among laboratories. To...

Free recombination within Helicobacter pylori

Suerbaum, Sebastian, Smith, John Maynard, Bapumia, Khairun, Morelli, Giovanna, Smith, Noel H., Kunstmann, Erdmute, ...

Sequences of three gene fragments (flaA, flaB, and vacA) from Helicobacter pylori strains isolated from patients in Germany, Canada, and South Africa were analyzed for diversity and for linkage...

Yersinia pestis, the cause of plague, is a recently emerged clone of Yersinia pseudotuberculosis

Achtman, Mark, Zurth, Kerstin, Morelli, Giovanna, Torrea, Gabriela, Guiyoule, Annie, Carniel, Elisabeth

Plague, one of the most devastating diseases of human history, is caused by Yersinia pestis. In this study, we analyzed the population genetic structure of Y. pestis and the two other pathogenic...

Fit genotypes and escape variants of subgroup III Neisseria meningitidis during three pandemics of epidemic meningitis

Zhu, Peixuan, Van Der Ende, Arie, Falush, Daniel, Brieske, Norbert, Morelli, Giovanna, Linz, Bodo, ...

The genetic variability at six polymorphic loci was examined within a global collection of 502 isolates of subgroup III, serogroup A Neisseria meningitidis. Nine “genoclouds” were identified,...

Recombination and mutation during long-term gastric colonization by Helicobacter pylori: Estimates of clock rates, recombination size, and minimal age

Falush, Daniel, Kraft, Christian, Taylor, Nancy S., Correa, Pelayo, Fox, James G., Achtman, Mark, ...

The bacterium Helicobacter pylori colonizes the gastric mucosa of half of the human population, resulting in chronic gastritis, ulcers, and cancer. We sequenced ten gene fragments from pairs of...

Functional Activities and Immunoglobulin Variable Regions of Human and Murine Monoclonal Antibodies Specific for the P1.7 PorA Protein Loop of Neisseria meningitidis†

Wang, Jianfu, Jarvis, Gary A., Achtman, Mark, Rosenqvist, Einar, Michaelsen, Terje E., Aase, Audun, ...

The meningococcal PorA protein is considered a promising vaccine candidate. Although much is understood regarding the structure of PorA proteins, little is known about the structure-function...

Molecular and Biological Analysis of Eight Genetic Islands That Distinguish Neisseria meningitidis from the Closely Related Pathogen Neisseria gonorrhoeae

Klee, Silke R., Nassif, Xavier, Kusecek, Barica, Merker, Petra, Beretti, Jean-Luc, Achtman, Mark, ...

The pathogenic species Neisseria meningitidis and Neisseria gonorrhoeae cause dramatically different diseases despite strong relatedness at the genetic and biochemical levels. N. meningitidis can...

Carcinoembryonic Antigen Family Receptor Specificity of Neisseria meningitidis Opa Variants Influences Adherence to and Invasion of Proinflammatory Cytokine-Activated Endothelial Cells

Muenzner, Petra, Dehio, Christoph, Fujiwara, Taku, Achtman, Mark, Meyer, Thomas F., Gray-Owen, Scott D.

The carcinoembryonic antigen (CEA) family member CEACAM1 (previously called biliary glycoprotein or CD66a) was previously shown to function as a receptor that can mediate the binding of Opa...

Randomly Amplified Polymorphic DNA Genotyping of Serogroup A Meningococci Yields Results Similar to Those Obtained by Multilocus Enzyme Electrophoresis and Reveals New Genotypes

Bart, Aldert, Schuurman, Ilse G. A., Achtman, Mark, Caugant, Dominique A., Dankert, Jacob, Van Der Ende, Arie

Randomly amplified polymorphic DNA (RAPD) genotyping was applied to one representative strain of each of the 84 electrophoretic types (ETs) of Neisseria meningitidis serogroup A previously defined by...

Necessity of Molecular Techniques To Distinguish between Neisseria meningitidis Strains Isolated from Patients with Meningococcal Disease and from Their Healthy Contacts

Vogel, Ulrich, Morelli, Giovanna, Zurth, Kerstin, Claus, Heike, Kriener, Eugen, Achtman, Mark, ...

Serogroup C strains of Neisseria meningitidis were isolated from a Germany patient with severe meningococcal disease after a trip to the Czech Republic. These strains (case isolates) were...

Sequence Diversity, Predicted Two-Dimensional Protein Structure, and Epitope Mapping of Neisserial Opa Proteins

Malorny, Burkhard, Morelli, Giovanna, Kusecek, Barica, Kolberg, Jan, Achtman, Mark

The sequence diversity of 45 Opa outer membrane proteins from Neisseria meningitidis, Neisseria gonorrhoeae, Neisseria sicca, and Neisseria flava indicates that horizontal genetic exchange of opa...

Crystal structure of the OpcA integral membrane adhesin from Neisseria meningitidis

Prince, Stephen M., Achtman, Mark, Derrick, Jeremy P.

OpcA is an integral outer membrane protein from Neisseria meningitidis, the causative agent of meningococcal meningitis and septicemia. It mediates the adhesion of N. meningitidis to epithelial and...

Conjugational Complementation Analysis of Transfer-Deficient Mutants of Flac in Escherichia coli

Achtman, Mark, Willetts, Neil, Clark, Alvin J.

A series of 102 transfer-deficient (tra−) mutants of Flac (84 of which have been previously described) were classified as carrying frameshift, amber, ochre, UGA, and nonsuppressible mutations....

Genetic Analysis of Transfer by the Escherichia coli Sex Factor F, Using P1 Transductional Complementation

Willetts, Neil, Achtman, Mark

P1 transduction has been used to perform a complementation analysis of a series of transfer-deficient mutants of Flac. The results define ten cistrons and are consistent with the results of a...

Beginning a Genetic Analysis of Conjugational Transfer Determined by the F Factor in Escherichia coli by Isolation and Characterization of Transfer-Deficient Mutants

Achtman, Mark, Willetts, Neil, Clark, Alvin J.

Eighty-four transfer-deficient mutants of Flac have been isolated; 27 of these bear amber mutations and 1 mutant is temperature-sensitive. All the mutants transfer between 10−2 and

traG protein of the F sex factor of Escherichia coli K-12 and its role in conjugation

Manning, Paul A., Morelli, Giovanna, Achtman, Mark

The traG protein of the F sex factor is an inner membrane protein with a molecular weight of 116,000. Mutants in traG (or in traN) are able to trigger conjugal DNA replication even though they cannot...

Distinguishing human ethnic groups by means of sequences from Helicobacter pylori: Lessons from Ladakh

Wirth, Thierry, Wang, Xiaoyan, Linz, Bodo, Novick, Richard P., Lum, J. Koji, Blaser, Martin, ...

The history of mankind remains one of the most challenging fields of study. However, the emergence of anatomically modern humans has been so recent that only a few genetically informative...

Fertility repression of F-like conjugative plasmids: Physical mapping of the R6-5 finO and finP cistrons and identification of the finO protein

Timmis, Kenneth N., Andrés, Isabel, Achtman, Mark

The locations of the fertility inhibition genes finO and finP of the F-like conjugative multiple antibiotic-resistance plasmid R6-5 have been determined. As found previously for that of the fertility...

Microevolution and history of the plague bacillus, Yersinia pestis

Achtman, Mark, Morelli, Giovanna, Zhu, Peixuan, Wirth, Thierry, Diehl, Ines, Kusecek, Barica, ...

The association of historical plague pandemics with Yersinia pestis remains controversial, partly because the evolutionary history of this largely monomorphic bacterium was unknown. The...

Gain and Loss of Multiple Genes During the Evolution of Helicobacter pylori

Gressmann, Helga, Linz, Bodo, Ghai, Rohit, Pleissner, Klaus-Peter, Schlapbach, Ralph, Yamaoka, Yoshio, ...

Sequence diversity and gene content distinguish most isolates of Helicobacter pylori. Even greater sequence differences differentiate distinct populations of H. pylori from different continents, but...

Who Ate Whom? Adaptive Helicobacter Genomic Changes That Accompanied a Host Jump from Early Humans to Large Felines

Eppinger, Mark, Baar, Claudia, Linz, Bodo, Raddatz, Günter, Lanz, Christa, Keller, Heike, ...

Helicobacter pylori infection of humans is so old that its population genetic structure reflects that of ancient human migrations. A closely related species, Helicobacter acinonychis, is specific for...

Characterization of the Pilin Ortholog of the Helicobacter pylori Type IV cag Pathogenicity Apparatus, a Surface-Associated Protein Expressed during Infection†

Andrzejewska, Joanna, Lee, Sae Kyung, Olbermann, Patrick, Lotzing, Nina, Katzowitsch, Elena, Linz, Bodo, ...

The Helicobacter pylori cag pathogenicity island (cag PAI) encodes components of a type IV secretion system (T4SS) involved in host interaction and pathogenicity. Previously, seven cag PAI proteins...

Sex and virulence in Escherichia coli: an evolutionary perspective

Wirth, Thierry, Falush, Daniel, Lan, Ruiting, Colles, Frances, Mensa, Patience, Wieler, Lothar H, ...

Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals...

Meningococcal Genetic Variation Mechanisms Viewed through Comparative Analysis of Serogroup C Strain FAM18

Bentley, Stephen D, Vernikos, George S, Snyder, Lori A. S, Churcher, Carol, Arrowsmith, Claire, Chillingworth, Tracey, ...

The bacterium Neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. Occasionally strains can invade host tissues causing septicaemia and...

Clonal Waves of Neisseria Colonisation and Disease in the African Meningitis Belt: Eight- Year Longitudinal Study in Northern Ghana

Leimkugel, Julia, Hodgson, Abraham, Forgor, Abudulai Adams, Pflüger, Valentin, Dangy, Jean-Pierre, Smith, Tom, ...

An analysis of pharyngeal carriage of meningococci in one district of Ghana examined the features of the isolates that might contribute to the susceptibility to meningococcal epidemics in the African...

A bimodal pattern of relatedness between the Salmonella Paratyphi A and Typhi genomes: Convergence or divergence by homologous recombination?

Didelot, Xavier, Achtman, Mark, Parkhill, Julian, Thomson, Nicholas R., Falush, Daniel

All Salmonella can cause disease but severe systemic infections are primarily caused by a few lineages. Paratyphi A and Typhi are the deadliest human restricted serovars, responsible for ∼600,000...

Mismatch induced speciation in Salmonella: model and data

Falush, Daniel, Torpdahl, Mia, Didelot, Xavier, Conrad, Donald F, Wilson, Daniel J, Achtman, Mark

In bacteria, DNA sequence mismatches act as a barrier to recombination between distantly related organisms and can potentially promote the cohesion of species. We have performed computer simulations...

The rise and spread of a new pathogen: Seroresistant Moraxella catarrhalis

Wirth, Thierry, Morelli, Giovanna, Kusecek, Barica, Van Belkum, Alex, Van Der Schee, Cindy, Meyer, Axel, ...

The nosocomial human pathogen Moraxella catarrhalis is one the most important agents of human respiratory tract infections. This species is composed of two distinct lineages, one of only moderate...

High-Throughput Genotyping of Salmonella enterica Serovar Typhi Allowing Geographical Assignment of Haplotypes and Pathotypes within an Urban District of Jakarta, Indonesia ▿ †

Baker, Stephen, Holt, Kathryn, Van De Vosse, Esther, Roumagnac, Philippe, Whitehead, Sally, King, Emma, ...

High-throughput epidemiological typing systems that provide phylogenetic and genotypic information are beneficial for tracking bacterial pathogens in the field. The incidence of Salmonella enterica...

Horizontal versus Familial Transmission of Helicobacter pylori

Schwarz, Sandra, Morelli, Giovanna, Kusecek, Barica, Manica, Andrea, Balloux, Francois, Owen, Robert J., ...

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large...

Ceftriaxone-Resistant Salmonella enterica Serotype Newport, France

Egorova, Svetlana, Timinouni, Mohammed, Demartin, Marie, Granier, Sophie A., Whichard, Jean M., Sangal, Vartul, ...

The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 β-lactamase (Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during...

Fate of the H-NS–Repressed bgl Operon in Evolution of Escherichia coli

Sankar, T. Sabari, Neelakanta, Girish, Sangal, Vartul, Plum, Georg, Achtman, Mark, Schnetz, Karin

In the enterobacterial species Escherichia coli and Salmonella enterica, expression of horizontally acquired genes with a higher than average AT content is repressed by the nucleoid-associated...

Frequent emergence and limited geographic dispersal of methicillin-resistant Staphylococcus aureus

Nübel, Ulrich, Roumagnac, Philippe, Feldkamp, Mirjam, Song, Jae-Hoon, Ko, Kwan Soo, Huang, Yhu-Chering, ...

A small number of clonal lineages dominates the global population structure of methicillin-resistant Staphylococcus aureus (MRSA), resulting in the concept that MRSA has emerged on a few occasions...

Clonal Groupings in Serogroup X Neisseria meningitidis

Gagneux, Sébastien, Wirth, Thierry, Hodgson, Abraham, Ehrhard, Ingrid, Morelli, Giovanna, Kriz, Paula, ...

The genetic diversity of 134 serogroup X Neisseria meningitis isolates from Africa, Europe, and North America was analyzed by multilocus sequence typing and pulsed-field gel electrophoresis. Although...