Martin J. Blaser

THE CROSS CONTAMINATION OF MAIL (2009)

Glenn F. Webb, Martin J. Blaser

(1) Develop a mathematical model of the fall 2001 anthrax attack on the US Postal System (2) Use the model to estimate the number of cross contaminated letters produced, the number of anthrax spores...

The equilibria that allow bacterial persistence in human hosts (2007)

Blaser, Martin J., Kirschner, Denise

We propose that microbes that have developed persistent relationships with human hosts have evolved cross-signalling mechanisms that permit homeostasis that conforms to Nash equilibria and, more...

Early-Life Family Structure and Microbially Induced Cancer Risk (2007)

Martin J. Blaser, Abraham Nomura, James Lee, Grant N. Stemmerman

BackgroundCancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma,...

Humoral Immune Response to Lipopolysaccharide Antigens of Campylobacter jejuni (2007)

Blaser, Martin J., Perez-Perez, Guillermo I.

Campylobacter jejuni and the closely related organism Campylobacter coli have been established as among the most common bacterial causes of acute diarrheal disease of humans in developed and...

Evaluation of Cytotoxic Activity in Fecal Filtrates from Patients with Campylobacter jejuni or Campylobacter coli enteritis (2007)

Cover, Timothy L., Perez-Perez, Guillermo I., Blaser, Martin J.

Although Campylobacter jejuni and C. coli are important causes of diarrheal illness worldwide, the pathophysiologic mechanisms whereby these organisms cause human disease remain poorly understood...

Role of Infection Due to Campylobacter jejuni in the Initiation of Guillain-Barre Syndrome (2007)

Mishu, Ban, Blaser, Martin J.

Recent reports suggest that infection with Campylobacter jejuni, a common enteric pathogen, may cause Guillain-Barre syndrome (GBS) by triggering demyelination of peripheral nerves. GBS is preceded...

Lack of Evidence of Enterotoxin Involvement in Pathogenesis of Campylobacter Diarrhea (2007)

Perez-Perez, Guillermo I., Taylor, David N., Echerverria, Peter D., Blaser, Martin J.

Several Campylobacter species are now recognized as important pathogens causing human diarrheal disease (7,8), but specific virulence mechanisms are not yet well defined. Campylobacter jejuni and C....

PEB1, the Major Cell-Binding Factor of Campylobacter jejuni, Is a Homolog of the Binding Component in Gram-Negative Nutrient Transport System (2007)

Pei, Shiheng, Blaser, Martin J.

The protein PEB1 (28 kDa) is a common antigen and a major cell adherence molecule of Campylobacter jejuni and Campylobacter coli. We created a bank of chromosomal DNA fragments of C. jejuni strain...

Human Volunteer Studies with Campylobacter jejuni (2007)

Black, Robert E., Perlman, Daniel, Clements, Mary L., Levine, Myron M., Blaser, Martin J.

Campylobacter jejuni and closely related organisms are established enteropathogens, resulting in diarrhea and often dysentery in susceptible children and adults (6). These organisms also cause...

An Outbreak of Bacteremic Campylobacter jejuni Infection (2007)

Shandera, Wayne X., Tormey, Michael P., Blaser, Martin J.

During September 1980, an outbreak of bacteremic Campylobacter jejuni infection occurred in metropolitan Los Angeles. The outbreak was recognized when blood cultures obtained from 11 previously...

Identification, Purification and Characterization of Major Antigenic Proteins of Campylobacter jejuni (2007)

Pei, Zhiheng, Blaser, Martin J.

Evidence from developing countries and volunteer studies indicates that immunity to Campylobacter jejuni and Campylobacter coli maybe acquired, but the antigenic basis for this protection is poorly...

Isolation and Characterization of Two Campylobacter Glycine-Extracted Proteins That Bind to HeLa Cell Membranes (2007)

Kervella, Michele, Pages, Jean-Marie, Pei, Zhiheng, Grollier, Chislaine, Blaser, Martin J.

Two immunogenic proteins of 27 (CBF1) and 29 (CBF2) kDa from enteropathogenic Campylobacter species appear to bind to mammalian cells. We purified these two proteins from a pathogenic and adherent...

Detection of Pathogenic Campylobacter Species in Blood Culture Systems (2007)

Wang, Wen-Lang, Blaser, Martin J.

Because differences in recognition of Campylobacter fetus and Campylobacter jejuni in systemic infectious may be due partially to differences in the ability to cultivate these organisms, we studied...

Evidence of host-virus co-evolution in tetranucleotide usage patterns of bacteriophages and eukaryotic viruses (2006)

Pride, David T, Wassenaar, Trudy M, Ghose, Chandrabali, Blaser, Martin J

Abstract Background Virus taxonomy is based on morphologic characteristics, as there are no widely used non-phenotypic measures for comparison among virus families. We examined whether there is...

Opposing Risks of Gastric Cardia and Noncardia Gastric Adenocarcinomas Associated With Helicobacter pylori Seropositivity (2006)

Kamangar, Farin, Dawsey, Sanford M., Blaser, Martin J., Perez-Perez, Guillermo I., Pietinen, Pirjo, Newschaffer, Craig J., ...

Background: Colonization with Helicobacter pylori is a risk factor for gastric adenocarcinoma, but the magnitude of this association and its relationship to anatomic location of the cancer, duration...

Helicobacter pylori and Overweight Status in the United States: Data from the Third National Health and Nutrition Examination Survey (2005)

Cho, Ilseung, Blaser, Martin J., François, Fritz, Mathew, Jomol P., Ye, Xiang Y., Goldberg, Judith D., ...

Obesity is an important public health problem in the United States. Because of its potential effects on gastric leptin homeostasis, Helicobacter pylori may play a role in regulating body weight. The...

Helicobacter pylori and Overweight Status in the United States: Data from the Third National Health and Nutrition Examination Survey (2005)

Cho, Ilseung, Blaser, Martin J., François, Fritz, Mathew, Jomol P., Ye, Xiang Y., Goldberg, Judith D., ...

Obesity is an important public health problem in the United States. Because of its potential effects on gastric leptin homeostasis, Helicobacter pylori may play a role in regulating body weight. The...

Helicobacter pylori and Overweight Status in the United States: Data from the Third National Health and Nutrition Examination Survey (2005)

Cho, Ilseung, Blaser, Martin J., François, Fritz, Mathew, Jomol P., Ye, Xiang Y., Goldberg, Judith D., ...

Obesity is an important public health problem in the United States. Because of its potential effects on gastric leptin homeostasis, Helicobacter pylori may play a role in regulating body weight. The...

Functional Adaptation of BabA, the H. pylori ABO Blood Group Antigen Binding Adhesin (2004)

Aspholm-Hurtig, Marina, Dailide, Giedrius, Lahmann, Martina, Kalia, Awdhesh, Ilver, Dag, Roche, Niamh, ...

Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens...

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...

Evolutionary Implications of Microbial Genome Tetranucleotide Frequency Biases (2003)

Pride, David T., Meinersmann, Richard J., Wassenaar, Trudy M., Blaser, Martin J.

We compared nucleotide usage pattern conservation for related prokaryotes by examining the representation of DNA tetranucleotide combinations in 27 representative microbial genomes. For each of the...

Relation between Helicobacter pylori cagA Status and Risk of Peptic Ulcer Disease (2002)

Nomura, Abraham M. Y., Pérez-Pérez, Guillermo I., Lee, James, Stemmermann, Grant, Blaser, Martin J.

Although colonization with any Helicobacter pylori strain is associated with peptic ulcer, it is uncertain whether the risk is greater with cagA+ or cagA− strains, which differ in their...

Phenotypic and genotypic variation in methylases involved in type II restriction-modification systems in Helicobacter pylori (2002)

Takata, Tohru, Aras, Rahul, Tavakoli, Donald, Ando, Takafumi, Olivares, Asalia Z., Blaser, Martin J.

To determine relationships between Helicobacter pylori geographical origin and type II methylase activity, we examined 122 strains from various locations around the world for methylase expression....

Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains (2002)

Aras, Rahul A., Small, Aaron J., Ando, Takafumi, Blaser, Martin J.

Helicobacter pylori, bacteria that colonize the human gastric mucosa, possess a large number of genes for restriction‐modification (R‐M) systems, and essentially, every strain possesses a...

Helicobacter pylori Seropositivity and Subsite-Specific Gastric Cancer Risks in Linxian, China (2001)

Limburg, Paul J., Qiao, You-Lin, Mark, Steven D., Wang, Guo-Qing, Perez-Perez, Guillermo I., Blaser, Martin J., ...

Background: Helicobacter pylori carriage (i.e., persistent exposure to the organism without gastric epithelial cell invasion) is an established risk factor for noncardia gastric cancer. However, its...

Helicobacter pylori Seropositivity as a Risk Factor for Pancreatic Cancer (2001)

Stolzenberg-Solomon, Rachael Z., Blaser, Martin J., Limburg, Paul J., Perez-Perez, Guillermo, Taylor, Philip R., Virtamo, Jarmo, ...

Background: Pancreatic cancer is among the most fatal cancers worldwide and one for which few preventable risk factors have been established. Gastric carriage of Helicobacter pylori, particularly...

Gastric Dysplasia and Gastric Cancer: Helicobacter pylori, Serum Vitamin C, and Other Risk Factors (2000)

You, Wei-cheng, Zhang, Lian, Gail, Mitchell H., Chang, Yun-sheng, Liu, Wei-dong, Ma, Jun-ling, ...

Background: Gastric cancer is generally thought to arise through a series of gastric mucosal changes, but the determinants of the precancerous lesions are not well understood. To identify such...

Erythromycin-Resistant Campylobacter Infections in Thailand, (1998)

Taylor, David N., Blaser, Martin J., Echeverria, Peter, Pitarangsi, Chittima, Bodhidatta, Ladaporn

Erythromycin therapy was compared with no treatment in a prospective trial of acute diarrheal disease among 100 infants in an orphanage in Bangkok. Within 24 h of the onset of diarrhea, 50 children...

Helicobacter pylori and Atrophic Gastritis: Importance of the cagA Status (1995)

Kuipers, Ernst J., Pérez-Pérez, Guillermo I., Meuwissen, Stephan G. M., Blaser, Martin J.

Background: Infection with Helicobacter pylori is a major risk factor for the development of atrophic gastritis and gastric cancer. H. pylori strains can differ with respect to the presence of cagA...

Molecular Probe Analysis of Shigella dysenteriae type 1 Isolates from 1940 to 1987 (1992)

BLASER, MARTIN J, MIOTTO, KAREN, HOPKINS, JANET A

Fourteen strains of Shigeila dysenteriae type 1 (Shiga bacillus) isolated from people in diverse locations from 1940 to 1987 were studied. Southern hybridization with three cloned Escherichia coli...

Gastric Adenocarcinoma and Helicobacter pylori Infection (1991)

Talley, Nicholas J., Zinsmeister, Alan R., Weaver, Amy, DiMagno, Eugene P., Carpenter, Herschel A., Perez-Perez, Guillermo I., ...

Helicobacter pylori infection, thought to be causally related to chronic gastritis, may also be associated with an increased risk of gastric cancer. To determine whether an association with gastric...

Campylobacter jejuni-specific serum antibodies are elevated in healthy Bangladeshi children (1985)

Blaser, Martin J., Black, Robert E., Amer, Jules

In Bangladesh and other developing countries, isolation of Campylobacter jejuni is common in healthy children, and the illness/infection ratio falls with age. To determine whether specific serum...

HUMAN CAMPYLOBACTER INFECTION ASSOCIATED WITH CERTIFIED RAW MILK (1983)

POTTER, MORRIS E., BLASER, MARTIN J., SIKES, R. KEITH, KAUFMANN, ARNOLD F., WELLS, JOY G.

Potter, M. E. (Bacterial Diseases Division, CDC, Atlanta, GA 30333), M. J. Blaser, R. K. Sikes, A. F. Kaufmann and J. G. Wells. Human Campylobacter infection associated with certified raw milk. Am J...

Salmonellosis at rural and urban clinics in Bangladesh: epidemiologic and clinical characteristics (1982)

Blaser, Martin J., Huq, M. Imdadul, Glass, Roger I., Zimicki, Susan, Birkness, Kristin A.

The authors studied the frequency of diarrheal illness associated with non-typhi Salmonella at two clinics in Bangladesh for the years 1977-1979. Non-typhi salmonellae were isolated from 0.29% of...

SALMONELLOSIS AT RURAL AND URBAN CLINICS IN BANGLADESH: EPIDEMIOLOGIC AND CLINICAL CHARACTERISTICS (1982)

BLASER, MARTIN J., HUQ, M. IMDADUL, GLASS, ROGER I., ZIMICKI, SUSAN, BIRKNESS, KRISTIN A.

The authors studied the frequency of diarrheal Illness associated with non-typhi Salmonella at two clinics in Bangladesh for the years 1977–1979. Non-typhl saimoneilae were isolated from...

AN OUTBREAK OF SALMONELLOSIS INVOLVING MULTIPLE VEHICLES (1981)

BLASER, MARTIN J., RAFUSE, EARLE M., WELLS, JOY G., POLLARD, ROBERT A., FELDMAN, ROGER A.

A biphasic outbreak of salmonellosis affected customers and employees of a restaurant in Maine, in October and November, 1979. Salmonella typhimurium was isolated from 27 customers and nine...

Isolation of Campylobacter fetus subsp. jejuni from Bangladeshi children (1980)

Blaser, Martin J., Glass, Roger I., Huq, M. Imdadul, Stoll, Barbara, Kibriya, G.M.

To determine the prevalence of infection with Campylobacter fetus subsp. jejuni in Bangladesh, culture surveys were conducted among three populations. In Dacca, Campylobacter was isolated from 5.2%...

Identification of type II restriction and modification systems in Helicobacter pylori reveals their substantial diversity among strains

Xu, Qing, Morgan, Richard D., Roberts, Richard J., Blaser, Martin J.

A total of 22 type II restriction endonucleases with 18 distinct specificities have been identified in six Helicobacter pylori strains. Among these 18 specificities are three completely new...

Dynamics of Helicobacter pylori colonization in relation to the host response

Blaser, Martin J., Kirschner, Denise

The dynamics of Helicobacter pylori colonization from its acquisition through the development of steady-state are examined through a mathematical model that includes the host response. The model...

Epithelial attachment alters the outcome of Helicobacter pylori infection

Guruge, Janaki L., Falk, Per G., Lorenz, Robin G., Dans, Maria, Wirth, Hans-Peter, Blaser, Martin J., ...

Genetically defined in vivo models are needed to assess the importance of target cell attachment in bacterial pathogenesis. Gastric colonization by Helicobacter pylori in human populations is common...

Rapid Identification of Thermotolerant Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis from Various Geographic Locations by a GTPase-Based PCR-Reverse Hybridization Assay

Van Doorn, Leen-Jan, Burnens, André, Huysmans, Michael, Vandamme, Peter, Giesendorf, Belinda A. J., ...

Recently, a gene from Campylobacter jejuni encoding a putative GTPase was identified. Based on two semiconserved GTP-binding sites encoded within this gene, PCR primers were selected that allow...

Distinct Variants of Helicobacter pylori cagA Are Associated with vacA Subtypes

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Blaser, Martin J., Quint, Wim G. V.

The diversity of the cytotoxin-associated gene (cagA) of Helicobacter pylori was analyzed in 45 isolates obtained from nine countries. We examined variation in the 5′ end of the cagA open reading...

CagA Antibodies in Japanese Children with Nodular Gastritis or Peptic Ulcer Disease

Kato, Seiichi, Sugiyama, Toshiro, Kudo, Mineo, Ohnuma, Kenji, Ozawa, Kyoko, Iinuma, Kazuie, ...

cagA+ Helicobacter pylori strains have been linked to more severe gastric inflammation, peptic ulcer disease, and gastric cancer in adults, but there have been few studies of cagA in children. We...

Restriction Fragment Length Polymorphism Analysis Using Random Chromosomal Gene Probes for Epidemiological Analysis of Campylobacter jejuni Infections

Fujimoto, Shuji, Umene, Kenichi, Saito, Mitsumasa, Horikawa, Kazumi, Blaser, Martin J.

We have evaluated the ability of a new genotyping method for Campylobacter jejuni based on restriction fragment length polymorphisms using random chromosomal gene probes. DNAs from C. jejuni strains...

Assessment of Helicobacter pylori vacA and cagA Genotypes and Host Serological Response

Figueiredo, Céu, Quint, Wim, Nouhan, Nathalie, Van Den Munckhof, Henk, Herbrink, Paul, Scherpenisse, Joost, ...

Helicobacter pylori strains can be distinguished by genotyping of virulence-associated genes, such as vacA and cagA. Because serological discrimination between strain types would reduce the need for...

HP0333, a Member of the dprA Family, Is Involved in Natural Transformation in Helicobacter pylori

Ando, Takafumi, Israel, Dawn A., Kusugami, Kazuo, Blaser, Martin J.

Helicobacter pylori is naturally competent for DNA transformation, but the mechanism by which transformation occurs is not known. For Haemophilus influenzae, dprA is required for transformation by...

Promoters of the CATG-Specific Methyltransferase Gene hpyIM Differ between iceA1 and iceA2 Helicobacter pylori Strains

Xu, Qing, Blaser, Martin J.

Helicobacter pylori strains can be divided into two groups, based on the presence of two unrelated genes, iceA1 and iceA2, that occupy the same genomic locus. hpyIM, located immediately downstream of...

Campylobacter fetus Uses Multiple Loci for DNA Inversion within the 5′ Conserved Regions of sap Homologs

Tu, Zheng-Chao, Ray, Kevin C., Thompson, Stuart A., Blaser, Martin J.

Campylobacter fetus cells possess multiple promoterless sap homologs, each capable of expressing a surface layer protein (SLP) by utilizing a unique promoter present on a 6.2-kb invertible element....

Detection of Anti-VacA Antibody Responses in Serum and Gastric Juice Samples Using Type s1/m1 and s2/m2 Helicobacter pylori VacA Antigens

Perez-Perez, Guillermo I., Peek, Richard M., Atherton, John C., Blaser, Martin J., Cover, Timothy L.

Several different families of vacuolating toxin (vacA) alleles are present in Helicobacter pylori, and they encode products with differing functional activities. H. pylori strains containing certain...

Anti-CagA Immunoglobulin G Responses Correlate with Interleukin-8 Induction in Human Gastric Mucosal Biopsy Culture

Ando, Takafumi, Perez-Perez, Guillermo I., Kusugami, Kazuo, Ohsuga, Masahiro, Bloch, Karen C., Blaser, Martin J.

Helicobacter pylori persists in the human stomach despite eliciting both cellular and humoral immune responses and inducing proinflammatory cytokines. To determine whether local humoral and cytokine...

Detection and Characterization of Autoagglutination Activity by Campylobacter jejuni

Misawa, Naoaki, Blaser, Martin J.

In several gram-negative bacterial pathogens, autoagglutination (AAG) activity is a marker for interaction with host cells and virulence. Campylobacter jejuni strains also show AAG, but this property...

Allelic Variation within Helicobacter pylori babA and babB

Pride, David T., Meinersmann, Richard J., Blaser, Martin J.

Helicobacter pylori strains show both geographic and disease-associated allelic variation. We investigated the diversity present in two genes, babA and babB, which are members of a paralogous family...

Evidence that the Campylobacter fetus sap Locus Is an Ancient Genomic Constituent with Origins before Mammals and Reptiles Diverged

Tu, Zheng-Chao, Dewhirst, Floyd E., Blaser, Martin J.

Campylobacter fetus bacteria, isolated from both mammals and reptiles, may be either subsp. fetus or subsp. venerealis and either serotype A or serotype B. Surface layer proteins, expressed and...

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Peek, Richard M., Van Doorn, Leen-Jan, Donahue, John P., Tham, Kyi T., Figueiredo, Ceu, Blaser, Martin J., ...

The iceA locus of Helicobacter pylori includes one of two mutually exclusive gene families, iceA1 and iceA2. Colonization with iceA1 strains is associated with enhanced acute mucosal inflammation,...

Campylobacter fetus sap Inversion Occurs in the Absence of RecA Function

Ray, Kevin C., Tu, Zheng-Chao, Grogono-Thomas, Rosemary, Newell, Diane G., Thompson, Stuart A., Blaser, Martin J.

Phase variation of Campylobacter fetus surface layer proteins (SLPs) occurs by inversion of a 6.2-kb DNA segment containing the unique sap promoter, permitting expression of a single SLP-encoding...

Helicobacter pylori Heat Shock Protein A: Serologic Responses and Genetic Diversity

Ng, Enders K. W., Thompson, Stuart A., Pérez-Pérez, Guillermo I., Kansau, Imad, Van Der Ende, Arie, Labigne, Agnès, ...

Helicobacter pylori synthesizes an unusual GroES homolog, heat shock protein A (HspA). The present study was aimed at an assessment of the serological response to HspA in a group of Chinese patients...

Expanding Allelic Diversity of Helicobacter pylori vacA

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Pena, Salvador, Midolo, Peter, Ng, Enders K. W., ...

The diversity of the gene encoding the vacuolating cytotoxin (vacA) of Helicobacter pylori was analyzed in 98 isolates obtained from different geographic locations. The studies focused on variation...

Differentiation of Campylobacter jejuni Serotype O19 Strains from Non-O19 Strains by PCR

Misawa, Naoaki, Allos, Ban Mishu, Blaser, Martin J.

Guillain-Barré syndrome (GBS), a neurologic disease characterized by acute paralysis, is frequently preceded by Campylobacter jejuni infection. Serotype O19 strains are overrepresented among...

Evidence for a Conjugation-Like Mechanism of DNA Transfer in Helicobacter pylori

Kuipers, Ernst J., Israel, Dawn A., Kusters, Johannes G., Blaser, Martin J.

Many strains of Helicobacter pylori are naturally competent for transformation in vitro. Since there is a high degree of genetic variation among H. pylori strains, we sought to determine whether...

Campylobacter fetus Surface Layer Proteins Are Transported by a Type I Secretion System

Thompson, Stuart A., Shedd, Omer L., Ray, Kevin C., Beins, Michael H., Jorgensen, Jesse P., Blaser, Martin J.

The virulence of Campylobacter fetus, a bacterial pathogen of ungulates and humans, is mediated in part by the presence of a paracrystalline surface layer (S-layer) that confers serum resistance. The...

Mutation in the peb1A Locus of Campylobacter jejuni Reduces Interactions with Epithelial Cells and Intestinal Colonization of Mice

Pei, Zhiheng, Burucoa, Christophe, Grignon, Bernadette, Baqar, Shahida, Huang, Xiao-Zhe, Kopecko, Dennis J., ...

Campylobacter jejuni is one of the leading causes of bacterial diarrhea throughout the world. We previously found that PEB1 is a homolog of cluster 3 binding proteins of bacterial ABC transporters...

Differential Normalization of Mucosal Interleukin-8 and Interleukin-6 Activity after Helicobacter pylori Eradication

Ando, Takafumi, Kusugami, Kazuo, Ohsuga, Masahiro, Ina, Kenji, Shinoda, Masataka, Konagaya, Toshihiro, ...

There is differential resolution of mucosal infiltration with neutrophils and mononuclear cells following successful Helicobacter pylori eradication. We investigated the effects of H. pylori...

Experimental Infection of Mongolian Gerbils with Wild-Type and Mutant Helicobacter pylori Strains

Wirth, Hans-Peter, Beins, Michael H., Yang, Manqiao, Tham, Kyi T., Blaser, Martin J.

Experimental Helicobacter pylori infection was studied in Mongolian gerbils with fresh human isolates that carry or do not carry cagA (cagA-positive or cagA-negative, respectively), multiply passaged...

Phenotypic and genotypic variation in methylases involved in type II restriction-modification systems in Helicobacter pylori

Takata, Tohru, Aras, Rahul, Tavakoli, Donald, Ando, Takafumi, Olivares, Asalia Z., Blaser, Martin J.

To determine relationships between Helicobacter pylori geographical origin and type II methylase activity, we examined 122 strains from various locations around the world for methylase expression....

Host Cell Responses to Genotypically Similar Helicobacter pylori Isolates from United States and Japan

Ando, Takafumi, Peek, Richard M., Lee, Yong-Chan, Krishna, Uma, Kusugami, Kazuo, Blaser, Martin J.

Associations of Helicobacter pylori genotypes with disease differ between Western countries and Asia. Therefore, we directly compared histopathological and in vitro responses to clinical isolates...

Mailborne transmission of anthrax: Modeling and implications

Webb, Glenn F., Blaser, Martin J.

A mathematical model is developed to analyze the transmission of inhalational anthrax through the postal system by cross-contamination of mail. The model consists of state vectors describing the...

Helicobacter pylori Does Not Require Lewis X or Lewis Y Expression To Colonize C3H/HeJ mice

Takata, Tohru, El-Omar, Emad, Camorlinga, Margarita, Thompson, Stuart A., Minohara, Yutaka, Ernst, Peter B., ...

Helicobacter pylori strains frequently express Lewis X (Lex) and/or Ley on their cell surfaces as constituents of the O antigens of their lipopolysaccharide molecules. To assess the effect of Lex and...

Responses of Endoscopy Patients in Ladakh, India, to Helicobacter pylori Whole-Cell and CagA Antigens

Romero-Gallo, Judith, Pérez-Pérez, Guillermo I., Novick, Richard P., Kamath, Patrick, Norbu, Tsering, Blaser, Martin J.

Although Helicobacter pylori is a cosmopolitan colonizer of the human stomach, the responses among persons in remote populations from whom H. pylori was cultured have not been studied. We report on...

Functional analysis of iceA1, a CATG-recognizing restriction endonuclease gene in Helicobacter pylori

Xu, Qing, Morgan, R. D., Roberts, R. J., Xu, S. Y., Van Doorn, L. J., Donahue, J. P., ...

iceA1 in Helicobacter pylori is a homolog of nlaIIIR, which encodes the CATG-specific restriction endonuclease NlaIII in Neisseria lactamica. Analysis of iceA1 sequences from 49 H.pylori strains...

East Asian genotypes of Helicobacter pylori strains in Amerindians provide evidence for its ancient human carriage

Ghose, Chandrabali, Perez-Perez, Guillermo I., Dominguez-Bello, Maria-Gloria, Pride, David T., Bravi, Claudio M., Blaser, Martin J.

Phylogenies of indigenous microbes have been used as surrogates for the origins of the hosts that carry them. Conversely, polymorphisms may be used to date the spread of a microbial species when...

PCR-Based Detection of Bacillus anthracis in Formalin-Fixed Tissue from a Patient Receiving Ciprofloxacin

Levine, Steven M., Perez-Perez, Guillermo, Olivares, Asalia, Yee, Herman, Hanna, Bruce A., Blaser, Martin J.

We demonstrate that Bacillus anthracis may be detected from a formalin-fixed, paraffin-embedded biopsy specimen, even after the patient has received antibiotic treatment. Although traditional PCR...

Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains

Aras, Rahul A., Small, Aaron J., Ando, Takafumi, Blaser, Martin J.

Helicobacter pylori, bacteria that colonize the human gastric mucosa, possess a large number of genes for restriction-modification (R-M) systems, and essentially, every strain possesses a unique...

Transient and Persistent Helicobacter pylori Colonization in Native American Children

Pérez-Pérez, Guillermo I., Sack, R. Bradley, Reid, Raymond, Santosham, Mathuram, Croll, Janne, Blaser, Martin J.

Helicobacter pylori is chiefly acquired in childhood, but the exact timing of acquisition is not well understood. The main goal of this study was to assess H. pylori acquisition in a pediatric...

Detection of a luxS-Signaling Molecule in Bacillus anthracis

Jones, Marcus B., Blaser, Martin J.

Quorum-sensing regulation of density-dependent genes has been described for numerous bacterial species. The partially annotated genome sequence of Bacillus anthracis contains an open reading frame...

Helicobacter pylori strain-specific differences in genetic content, identified by microarray, influence host inflammatory responses

Israel, Dawn A., Salama, Nina, Arnold, Carrie N., Moss, Steven F., Ando, Takafumi, Wirth, Hans-Peter, ...

Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori–colonized individuals develop disease. We examined the ability of two H. pylori isolates...

Extensive repetitive DNA facilitates prokaryotic genome plasticity

Aras, Rahul A., Kang, Josephine, Tschumi, Ariane I., Harasaki, Yasuaki, Blaser, Martin J.

Prokaryotic genomes are substantially diverse, even when from closely related species, with the resulting phenotypic diversity representing a repertoire of adaptations to specific constraints. Within...

Helicobacter pylori persistence: biology and disease

Blaser, Martin J., Atherton, John C.

Helicobacter pylori are bacteria that have coevolved with humans to be transmitted from person to person and to persistently colonize the stomach. Their population structure is a model for the...

Experimental Campylobacter jejuni Infection of Adult Mice

Blaser, Martin J., Duncan, Deborah J., Warren, George H., Wang, Wen-Lan L.

HA-ICR adult mice were studied to develop an animal model for Campylobacter jejuni enteritis in humans. Fecal and ileal cultures made by selective and nonselective methods showed that C. jejuni and...

Conservation and Diversity of sap Homologues and Their Organization among Campylobacter fetus Isolates

Tu, Zheng-Chao, Hui, John, Blaser, Martin J.

Campylobacter fetus surface layer proteins (SLPs), encoded by sapA homologues, are important in virulence. In wild-type C. fetus strain 23D, all eight sapA homologues are located in the 54-kb sap...

Bacterial biota in the human distal esophagus

Pei, Zhiheng, Bini, Edmund J., Yang, Liying, Zhou, Meisheng, Francois, Fritz, Blaser, Martin J.

The esophagus, like other luminal organs of the digestive system, provides a potential environment for bacterial colonization, but little is known about the presence of a bacterial biota or its...

Evolutionary Implications of Microbial Genome Tetranucleotide Frequency Biases

Pride, David T., Meinersmann, Richard J., Wassenaar, Trudy M., Blaser, Martin J.

We compared nucleotide usage pattern conservation for related prokaryotes by examining the representation of DNA tetranucleotide combinations in 27 representative microbial genomes. For each of the...

Campylobacter fetus of Reptile Origin as a Human Pathogen

Tu, Zheng-Chao, Zeitlin, Gary, Gagner, Jean-Pierre, Keo, Thormika, Hanna, Bruce A., Blaser, Martin J.

A Campylobacter species was isolated from blood from a febrile patient with precursor T-cell acute lymphoblastic leukemia, and after antibiotic treatment, a similar bacterium was isolated from blood...

Effect of Host Species on RecG Phenotypes in Helicobacter pylori and Escherichia coli

Kang, Josephine, Tavakoli, Don, Tschumi, Ariane, Aras, Rahul A., Blaser, Martin J.

Recombination is a fundamental mechanism for the generation of genetic variation. Helicobacter pylori strains have different frequencies of intragenomic recombination, arising from deletions and...

Structural and Functional Divergence of MutS2 from Bacterial MutS1 and Eukaryotic MSH4-MSH5 Homologs†

Kang, Josephine, Huang, Shuyan, Blaser, Martin J.

MutS homologs, identified in nearly all bacteria and eukaryotes, include the bacterial proteins MutS1 and MutS2 and the eukaryotic MutS homologs 1 to 7, and they often are involved in recognition and...

Genetic Divergence of Campylobacter fetus Strains of Mammal and Reptile Origins

Tu, Zheng-Chao, Eisner, William, Kreiswirth, Barry N., Blaser, Martin J.

Campylobacter fetus is a gram-negative bacterial pathogen of both humans and animals. Two subspecies have been identified, Campylobacter fetus subsp. fetus and Campylobacter fetus subsp. venerealis,...

Campylobacter Enteritis in Denver

Blaser, Martin J., Reller, L. Barth, Luechtefeld, Nancy W., Wang, Wen-Lan Lou

To determine the relative importance of Campylobacter jejuni as a cause of diarrheal illness in patients coming to three hospitals in Denver, we cultured stool specimens from 2,670 patients over a...

Local and Systemic Immune and Inflammatory Responses to Helicobacter pylori Strains

Bhat, Niranjan, Gaensbauer, James, Peek, Richard M., Bloch, Karen, Tham, Kyi-Toe, Blaser, Martin J., ...

Colonization with Helicobacter pylori eventuates in varied clinical outcomes, which relate to both bacterial and host factors. Here we examine the relationships between cagA status, serum and gastric...

Molecular analysis of the bacterial microbiota in the human stomach

Bik, Elisabeth M., Eckburg, Paul B., Gill, Steven R., Nelson, Karen E., Purdom, Elizabeth A., Francois, Fritz, ...

The microbiota of the human stomach and the influence of Helicobacter pylori colonization on its composition remain largely unknown. We characterized bacterial diversity within the human gastric...

Theodore E. Woodward Award: Global Warming and the Human Stomach: Microecology Follows Macroecology

Blaser, Martin J

Just as there have been 20th century changes in our “macroecology,” including global warming, there have been alterations in our “microecology,” involving the microbial populations that...

An Email Alert System for Internal Medicine Physicians

Triola, Marc M., Blaser, Martin J.

This study evaluated the effectiveness of an email-based alerting system for internal medicine house staff and faculty in geographically dispersed locales. Responses to a test alert email message...

UvrD Helicase Suppresses Recombination and DNA Damage-Induced Deletions†

Kang, Josephine, Blaser, Martin J.

UvrD, a highly conserved helicase involved in mismatch repair, nucleotide excision repair (NER), and recombinational repair, plays a critical role in maintaining genomic stability and facilitating...

Molecular Analysis of Fungal Microbiota in Samples from Healthy Human Skin and Psoriatic Lesions

Paulino, Luciana C., Tseng, Chi-Hong, Strober, Bruce E., Blaser, Martin J.

Psoriasis, a common cutaneous disease of unknown etiology, may be triggered by infections, including those due to fungi. Since the fungal community of human skin is poorly characterized, we aimed to...

Identification of type II restriction and modification systems in Helicobacter pylori reveals their substantial diversity among strains

Xu, Qing, Morgan, Richard D., Roberts, Richard J., Blaser, Martin J.

A total of 22 type II restriction endonucleases with 18 distinct specificities have been identified in six Helicobacter pylori strains. Among these 18 specificities are three completely new...

Dynamics of Helicobacter pylori colonization in relation to the host response

Blaser, Martin J., Kirschner, Denise

The dynamics of Helicobacter pylori colonization from its acquisition through the development of steady-state are examined through a mathematical model that includes the host response. The model...

Epithelial attachment alters the outcome of Helicobacter pylori infection

Guruge, Janaki L., Falk, Per G., Lorenz, Robin G., Dans, Maria, Wirth, Hans-Peter, Blaser, Martin J., ...

Genetically defined in vivo models are needed to assess the importance of target cell attachment in bacterial pathogenesis. Gastric colonization by Helicobacter pylori in human populations is common...

Rapid Identification of Thermotolerant Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis from Various Geographic Locations by a GTPase-Based PCR-Reverse Hybridization Assay

Van Doorn, Leen-Jan, Burnens, André, Huysmans, Michael, Vandamme, Peter, Giesendorf, Belinda A. J., ...

Recently, a gene from Campylobacter jejuni encoding a putative GTPase was identified. Based on two semiconserved GTP-binding sites encoded within this gene, PCR primers were selected that allow...

Distinct Variants of Helicobacter pylori cagA Are Associated with vacA Subtypes

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Blaser, Martin J., Quint, Wim G. V.

The diversity of the cytotoxin-associated gene (cagA) of Helicobacter pylori was analyzed in 45 isolates obtained from nine countries. We examined variation in the 5′ end of the cagA open reading...

CagA Antibodies in Japanese Children with Nodular Gastritis or Peptic Ulcer Disease

Kato, Seiichi, Sugiyama, Toshiro, Kudo, Mineo, Ohnuma, Kenji, Ozawa, Kyoko, Iinuma, Kazuie, ...

cagA+ Helicobacter pylori strains have been linked to more severe gastric inflammation, peptic ulcer disease, and gastric cancer in adults, but there have been few studies of cagA in children. We...

Restriction Fragment Length Polymorphism Analysis Using Random Chromosomal Gene Probes for Epidemiological Analysis of Campylobacter jejuni Infections

Fujimoto, Shuji, Umene, Kenichi, Saito, Mitsumasa, Horikawa, Kazumi, Blaser, Martin J.

We have evaluated the ability of a new genotyping method for Campylobacter jejuni based on restriction fragment length polymorphisms using random chromosomal gene probes. DNAs from C. jejuni strains...

Assessment of Helicobacter pylori vacA and cagA Genotypes and Host Serological Response

Figueiredo, Céu, Quint, Wim, Nouhan, Nathalie, Van Den Munckhof, Henk, Herbrink, Paul, Scherpenisse, Joost, ...

Helicobacter pylori strains can be distinguished by genotyping of virulence-associated genes, such as vacA and cagA. Because serological discrimination between strain types would reduce the need for...

HP0333, a Member of the dprA Family, Is Involved in Natural Transformation in Helicobacter pylori

Ando, Takafumi, Israel, Dawn A., Kusugami, Kazuo, Blaser, Martin J.

Helicobacter pylori is naturally competent for DNA transformation, but the mechanism by which transformation occurs is not known. For Haemophilus influenzae, dprA is required for transformation by...

Promoters of the CATG-Specific Methyltransferase Gene hpyIM Differ between iceA1 and iceA2 Helicobacter pylori Strains

Xu, Qing, Blaser, Martin J.

Helicobacter pylori strains can be divided into two groups, based on the presence of two unrelated genes, iceA1 and iceA2, that occupy the same genomic locus. hpyIM, located immediately downstream of...

Campylobacter fetus Uses Multiple Loci for DNA Inversion within the 5′ Conserved Regions of sap Homologs

Tu, Zheng-Chao, Ray, Kevin C., Thompson, Stuart A., Blaser, Martin J.

Campylobacter fetus cells possess multiple promoterless sap homologs, each capable of expressing a surface layer protein (SLP) by utilizing a unique promoter present on a 6.2-kb invertible element....

Detection of Anti-VacA Antibody Responses in Serum and Gastric Juice Samples Using Type s1/m1 and s2/m2 Helicobacter pylori VacA Antigens

Perez-Perez, Guillermo I., Peek, Richard M., Atherton, John C., Blaser, Martin J., Cover, Timothy L.

Several different families of vacuolating toxin (vacA) alleles are present in Helicobacter pylori, and they encode products with differing functional activities. H. pylori strains containing certain...

Anti-CagA Immunoglobulin G Responses Correlate with Interleukin-8 Induction in Human Gastric Mucosal Biopsy Culture

Ando, Takafumi, Perez-Perez, Guillermo I., Kusugami, Kazuo, Ohsuga, Masahiro, Bloch, Karen C., Blaser, Martin J.

Helicobacter pylori persists in the human stomach despite eliciting both cellular and humoral immune responses and inducing proinflammatory cytokines. To determine whether local humoral and cytokine...

Detection and Characterization of Autoagglutination Activity by Campylobacter jejuni

Misawa, Naoaki, Blaser, Martin J.

In several gram-negative bacterial pathogens, autoagglutination (AAG) activity is a marker for interaction with host cells and virulence. Campylobacter jejuni strains also show AAG, but this property...

Allelic Variation within Helicobacter pylori babA and babB

Pride, David T., Meinersmann, Richard J., Blaser, Martin J.

Helicobacter pylori strains show both geographic and disease-associated allelic variation. We investigated the diversity present in two genes, babA and babB, which are members of a paralogous family...

Evidence that the Campylobacter fetus sap Locus Is an Ancient Genomic Constituent with Origins before Mammals and Reptiles Diverged

Tu, Zheng-Chao, Dewhirst, Floyd E., Blaser, Martin J.

Campylobacter fetus bacteria, isolated from both mammals and reptiles, may be either subsp. fetus or subsp. venerealis and either serotype A or serotype B. Surface layer proteins, expressed and...

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Peek, Richard M., Van Doorn, Leen-Jan, Donahue, John P., Tham, Kyi T., Figueiredo, Ceu, Blaser, Martin J., ...

The iceA locus of Helicobacter pylori includes one of two mutually exclusive gene families, iceA1 and iceA2. Colonization with iceA1 strains is associated with enhanced acute mucosal inflammation,...

Campylobacter fetus sap Inversion Occurs in the Absence of RecA Function

Ray, Kevin C., Tu, Zheng-Chao, Grogono-Thomas, Rosemary, Newell, Diane G., Thompson, Stuart A., Blaser, Martin J.

Phase variation of Campylobacter fetus surface layer proteins (SLPs) occurs by inversion of a 6.2-kb DNA segment containing the unique sap promoter, permitting expression of a single SLP-encoding...

Helicobacter pylori Heat Shock Protein A: Serologic Responses and Genetic Diversity

Ng, Enders K. W., Thompson, Stuart A., Pérez-Pérez, Guillermo I., Kansau, Imad, Van Der Ende, Arie, Labigne, Agnès, ...

Helicobacter pylori synthesizes an unusual GroES homolog, heat shock protein A (HspA). The present study was aimed at an assessment of the serological response to HspA in a group of Chinese patients...

Expanding Allelic Diversity of Helicobacter pylori vacA

Van Doorn, Leen-Jan, Figueiredo, Céu, Sanna, Ricardo, Pena, Salvador, Midolo, Peter, Ng, Enders K. W., ...

The diversity of the gene encoding the vacuolating cytotoxin (vacA) of Helicobacter pylori was analyzed in 98 isolates obtained from different geographic locations. The studies focused on variation...

Differentiation of Campylobacter jejuni Serotype O19 Strains from Non-O19 Strains by PCR

Misawa, Naoaki, Allos, Ban Mishu, Blaser, Martin J.

Guillain-Barré syndrome (GBS), a neurologic disease characterized by acute paralysis, is frequently preceded by Campylobacter jejuni infection. Serotype O19 strains are overrepresented among...

Evidence for a Conjugation-Like Mechanism of DNA Transfer in Helicobacter pylori

Kuipers, Ernst J., Israel, Dawn A., Kusters, Johannes G., Blaser, Martin J.

Many strains of Helicobacter pylori are naturally competent for transformation in vitro. Since there is a high degree of genetic variation among H. pylori strains, we sought to determine whether...

Campylobacter fetus Surface Layer Proteins Are Transported by a Type I Secretion System

Thompson, Stuart A., Shedd, Omer L., Ray, Kevin C., Beins, Michael H., Jorgensen, Jesse P., Blaser, Martin J.

The virulence of Campylobacter fetus, a bacterial pathogen of ungulates and humans, is mediated in part by the presence of a paracrystalline surface layer (S-layer) that confers serum resistance. The...

Mutation in the peb1A Locus of Campylobacter jejuni Reduces Interactions with Epithelial Cells and Intestinal Colonization of Mice

Pei, Zhiheng, Burucoa, Christophe, Grignon, Bernadette, Baqar, Shahida, Huang, Xiao-Zhe, Kopecko, Dennis J., ...

Campylobacter jejuni is one of the leading causes of bacterial diarrhea throughout the world. We previously found that PEB1 is a homolog of cluster 3 binding proteins of bacterial ABC transporters...

Differential Normalization of Mucosal Interleukin-8 and Interleukin-6 Activity after Helicobacter pylori Eradication

Ando, Takafumi, Kusugami, Kazuo, Ohsuga, Masahiro, Ina, Kenji, Shinoda, Masataka, Konagaya, Toshihiro, ...

There is differential resolution of mucosal infiltration with neutrophils and mononuclear cells following successful Helicobacter pylori eradication. We investigated the effects of H. pylori...

Experimental Infection of Mongolian Gerbils with Wild-Type and Mutant Helicobacter pylori Strains

Wirth, Hans-Peter, Beins, Michael H., Yang, Manqiao, Tham, Kyi T., Blaser, Martin J.

Experimental Helicobacter pylori infection was studied in Mongolian gerbils with fresh human isolates that carry or do not carry cagA (cagA-positive or cagA-negative, respectively), multiply passaged...

Phenotypic and genotypic variation in methylases involved in type II restriction-modification systems in Helicobacter pylori

Takata, Tohru, Aras, Rahul, Tavakoli, Donald, Ando, Takafumi, Olivares, Asalia Z., Blaser, Martin J.

To determine relationships between Helicobacter pylori geographical origin and type II methylase activity, we examined 122 strains from various locations around the world for methylase expression....

Host Cell Responses to Genotypically Similar Helicobacter pylori Isolates from United States and Japan

Ando, Takafumi, Peek, Richard M., Lee, Yong-Chan, Krishna, Uma, Kusugami, Kazuo, Blaser, Martin J.

Associations of Helicobacter pylori genotypes with disease differ between Western countries and Asia. Therefore, we directly compared histopathological and in vitro responses to clinical isolates...

Mailborne transmission of anthrax: Modeling and implications

Webb, Glenn F., Blaser, Martin J.

A mathematical model is developed to analyze the transmission of inhalational anthrax through the postal system by cross-contamination of mail. The model consists of state vectors describing the...

Helicobacter pylori Does Not Require Lewis X or Lewis Y Expression To Colonize C3H/HeJ mice

Takata, Tohru, El-Omar, Emad, Camorlinga, Margarita, Thompson, Stuart A., Minohara, Yutaka, Ernst, Peter B., ...

Helicobacter pylori strains frequently express Lewis X (Lex) and/or Ley on their cell surfaces as constituents of the O antigens of their lipopolysaccharide molecules. To assess the effect of Lex and...

Responses of Endoscopy Patients in Ladakh, India, to Helicobacter pylori Whole-Cell and CagA Antigens

Romero-Gallo, Judith, Pérez-Pérez, Guillermo I., Novick, Richard P., Kamath, Patrick, Norbu, Tsering, Blaser, Martin J.

Although Helicobacter pylori is a cosmopolitan colonizer of the human stomach, the responses among persons in remote populations from whom H. pylori was cultured have not been studied. We report on...

Functional analysis of iceA1, a CATG-recognizing restriction endonuclease gene in Helicobacter pylori

Xu, Qing, Morgan, R. D., Roberts, R. J., Xu, S. Y., Van Doorn, L. J., Donahue, J. P., ...

iceA1 in Helicobacter pylori is a homolog of nlaIIIR, which encodes the CATG-specific restriction endonuclease NlaIII in Neisseria lactamica. Analysis of iceA1 sequences from 49 H.pylori strains...

East Asian genotypes of Helicobacter pylori strains in Amerindians provide evidence for its ancient human carriage

Ghose, Chandrabali, Perez-Perez, Guillermo I., Dominguez-Bello, Maria-Gloria, Pride, David T., Bravi, Claudio M., Blaser, Martin J.

Phylogenies of indigenous microbes have been used as surrogates for the origins of the hosts that carry them. Conversely, polymorphisms may be used to date the spread of a microbial species when...

PCR-Based Detection of Bacillus anthracis in Formalin-Fixed Tissue from a Patient Receiving Ciprofloxacin

Levine, Steven M., Perez-Perez, Guillermo, Olivares, Asalia, Yee, Herman, Hanna, Bruce A., Blaser, Martin J.

We demonstrate that Bacillus anthracis may be detected from a formalin-fixed, paraffin-embedded biopsy specimen, even after the patient has received antibiotic treatment. Although traditional PCR...

Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains

Aras, Rahul A., Small, Aaron J., Ando, Takafumi, Blaser, Martin J.

Helicobacter pylori, bacteria that colonize the human gastric mucosa, possess a large number of genes for restriction-modification (R-M) systems, and essentially, every strain possesses a unique...

Transient and Persistent Helicobacter pylori Colonization in Native American Children

Pérez-Pérez, Guillermo I., Sack, R. Bradley, Reid, Raymond, Santosham, Mathuram, Croll, Janne, Blaser, Martin J.

Helicobacter pylori is chiefly acquired in childhood, but the exact timing of acquisition is not well understood. The main goal of this study was to assess H. pylori acquisition in a pediatric...

Detection of a luxS-Signaling Molecule in Bacillus anthracis

Jones, Marcus B., Blaser, Martin J.

Quorum-sensing regulation of density-dependent genes has been described for numerous bacterial species. The partially annotated genome sequence of Bacillus anthracis contains an open reading frame...

Helicobacter pylori strain-specific differences in genetic content, identified by microarray, influence host inflammatory responses

Israel, Dawn A., Salama, Nina, Arnold, Carrie N., Moss, Steven F., Ando, Takafumi, Wirth, Hans-Peter, ...

Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori–colonized individuals develop disease. We examined the ability of two H. pylori isolates...

Extensive repetitive DNA facilitates prokaryotic genome plasticity

Aras, Rahul A., Kang, Josephine, Tschumi, Ariane I., Harasaki, Yasuaki, Blaser, Martin J.

Prokaryotic genomes are substantially diverse, even when from closely related species, with the resulting phenotypic diversity representing a repertoire of adaptations to specific constraints. Within...

Helicobacter pylori persistence: biology and disease

Blaser, Martin J., Atherton, John C.

Helicobacter pylori are bacteria that have coevolved with humans to be transmitted from person to person and to persistently colonize the stomach. Their population structure is a model for the...

Experimental Campylobacter jejuni Infection of Adult Mice

Blaser, Martin J., Duncan, Deborah J., Warren, George H., Wang, Wen-Lan L.

HA-ICR adult mice were studied to develop an animal model for Campylobacter jejuni enteritis in humans. Fecal and ileal cultures made by selective and nonselective methods showed that C. jejuni and...

Conservation and Diversity of sap Homologues and Their Organization among Campylobacter fetus Isolates

Tu, Zheng-Chao, Hui, John, Blaser, Martin J.

Campylobacter fetus surface layer proteins (SLPs), encoded by sapA homologues, are important in virulence. In wild-type C. fetus strain 23D, all eight sapA homologues are located in the 54-kb sap...

Bacterial biota in the human distal esophagus

Pei, Zhiheng, Bini, Edmund J., Yang, Liying, Zhou, Meisheng, Francois, Fritz, Blaser, Martin J.

The esophagus, like other luminal organs of the digestive system, provides a potential environment for bacterial colonization, but little is known about the presence of a bacterial biota or its...

Evolutionary Implications of Microbial Genome Tetranucleotide Frequency Biases

Pride, David T., Meinersmann, Richard J., Wassenaar, Trudy M., Blaser, Martin J.

We compared nucleotide usage pattern conservation for related prokaryotes by examining the representation of DNA tetranucleotide combinations in 27 representative microbial genomes. For each of the...

Campylobacter fetus of Reptile Origin as a Human Pathogen

Tu, Zheng-Chao, Zeitlin, Gary, Gagner, Jean-Pierre, Keo, Thormika, Hanna, Bruce A., Blaser, Martin J.

A Campylobacter species was isolated from blood from a febrile patient with precursor T-cell acute lymphoblastic leukemia, and after antibiotic treatment, a similar bacterium was isolated from blood...

Effect of Host Species on RecG Phenotypes in Helicobacter pylori and Escherichia coli

Kang, Josephine, Tavakoli, Don, Tschumi, Ariane, Aras, Rahul A., Blaser, Martin J.

Recombination is a fundamental mechanism for the generation of genetic variation. Helicobacter pylori strains have different frequencies of intragenomic recombination, arising from deletions and...

Structural and Functional Divergence of MutS2 from Bacterial MutS1 and Eukaryotic MSH4-MSH5 Homologs†

Kang, Josephine, Huang, Shuyan, Blaser, Martin J.

MutS homologs, identified in nearly all bacteria and eukaryotes, include the bacterial proteins MutS1 and MutS2 and the eukaryotic MutS homologs 1 to 7, and they often are involved in recognition and...

Genetic Divergence of Campylobacter fetus Strains of Mammal and Reptile Origins

Tu, Zheng-Chao, Eisner, William, Kreiswirth, Barry N., Blaser, Martin J.

Campylobacter fetus is a gram-negative bacterial pathogen of both humans and animals. Two subspecies have been identified, Campylobacter fetus subsp. fetus and Campylobacter fetus subsp. venerealis,...

Campylobacter Enteritis in Denver

Blaser, Martin J., Reller, L. Barth, Luechtefeld, Nancy W., Wang, Wen-Lan Lou

To determine the relative importance of Campylobacter jejuni as a cause of diarrheal illness in patients coming to three hospitals in Denver, we cultured stool specimens from 2,670 patients over a...

Local and Systemic Immune and Inflammatory Responses to Helicobacter pylori Strains

Bhat, Niranjan, Gaensbauer, James, Peek, Richard M., Bloch, Karen, Tham, Kyi-Toe, Blaser, Martin J., ...

Colonization with Helicobacter pylori eventuates in varied clinical outcomes, which relate to both bacterial and host factors. Here we examine the relationships between cagA status, serum and gastric...

Molecular analysis of the bacterial microbiota in the human stomach

Bik, Elisabeth M., Eckburg, Paul B., Gill, Steven R., Nelson, Karen E., Purdom, Elizabeth A., Francois, Fritz, ...

The microbiota of the human stomach and the influence of Helicobacter pylori colonization on its composition remain largely unknown. We characterized bacterial diversity within the human gastric...

Theodore E. Woodward Award: Global Warming and the Human Stomach: Microecology Follows Macroecology

Blaser, Martin J

Just as there have been 20th century changes in our “macroecology,” including global warming, there have been alterations in our “microecology,” involving the microbial populations that...

An Email Alert System for Internal Medicine Physicians

Triola, Marc M., Blaser, Martin J.

This study evaluated the effectiveness of an email-based alerting system for internal medicine house staff and faculty in geographically dispersed locales. Responses to a test alert email message...

UvrD Helicase Suppresses Recombination and DNA Damage-Induced Deletions†

Kang, Josephine, Blaser, Martin J.

UvrD, a highly conserved helicase involved in mismatch repair, nucleotide excision repair (NER), and recombinational repair, plays a critical role in maintaining genomic stability and facilitating...

Molecular Analysis of Fungal Microbiota in Samples from Healthy Human Skin and Psoriatic Lesions

Paulino, Luciana C., Tseng, Chi-Hong, Strober, Bruce E., Blaser, Martin J.

Psoriasis, a common cutaneous disease of unknown etiology, may be triggered by infections, including those due to fungi. Since the fungal community of human skin is poorly characterized, we aimed to...

Antimutator Role of the DNA Glycosylase mutY Gene in Helicobacter pylori

Huang, Shuyan, Kang, Josephine, Blaser, Martin J.

Helicobacter pylori has a highly variable genome with ongoing diversification via inter- and intragenomic recombination and spontaneous mutation. DNA repair genes modulating mutation and...

Early-Life Family Structure and Microbially Induced Cancer Risk

Blaser, Martin J, Nomura, Abraham, Lee, James, Stemmerman, Grant N, Perez-Perez, Guillermo I

This study suggests that early-life social environment has a significant role in risk of microbially induced malignancies such as gastric adenocarcinoma occuring five to eight decades later.

Serological Assays for Identification of Human Gastric Colonization by Helicobacter pylori Strains Expressing VacA m1 or m2 ▿†

Ghose, Chandrabali, Perez-Perez, Guillermo I., Torres, Victor J., Crosatti, Marialuisa, Nomura, Abraham, Peek, Richard M., ...

The Helicobacter pylori vacA gene encodes a secreted protein (VacA) that alters the function of gastric epithelial cells and T lymphocytes. H. pylori strains containing particular vacA alleles are...

Molecular analysis of human forearm superficial skin bacterial biota

Gao, Zhan, Tseng, Chi-hong, Pei, Zhiheng, Blaser, Martin J.

The microbial ecology of human skin is complex, but little is known about its species composition. We examined the diversity of the skin biota from the superficial volar left and right forearms in...

Plasticity of Repetitive DNA Sequences within a Bacterial (Type IV) Secretion System Component

Aras, Rahul A., Fischer, Wolfgang, Perez-Perez, Guillermo I., Crosatti, MariaLuisa, Ando, Takafumi, Haas, Rainer, ...

DNA rearrangement permits bacteria to regulate gene content and expression. In Helicobacter pylori, cagY, which contains an extraordinary number of direct DNA repeats, encodes a surface-exposed...

Reactive Nitrogen Species Contribute to Innate Host Defense against Campylobacter jejuni▿

Iovine, Nicole M., Pursnani, Seema, Voldman, Alex, Wasserman, Gregory, Blaser, Martin J., Weinrauch, Yvette

Campylobacter jejuni, a gram-negative, invasive organism, is a common cause of food-borne bacterial diarrheal disease. However, the relationship between C. jejuni and the innate immune system is not...

Substantial Alterations of the Cutaneous Bacterial Biota in Psoriatic Lesions

Gao, Zhan, Tseng, Chi-hong, Strober, Bruce E., Pei, Zhiheng, Blaser, Martin J.

For psoriasis, an idiopathic inflammatory disorder of the skin, the microbial biota has not been defined using cultivation-independent methods. We used broad-range 16S rDNA PCR for archaea and...

Repair and Antirepair DNA Helicases in Helicobacter pylori▿ †

Kang, Josephine, Blaser, Martin J.

Orthologs of RecG and RuvABC are highly conserved among prokaryotes; in Escherichia coli, they participate in independent pathways that branch migrate Holliday junctions during recombinational DNA...

Natural Transformation of Helicobacter pylori Involves the Integration of Short DNA Fragments Interrupted by Gaps of Variable Size

Lin, Edward A., Zhang, Xue-Song, Levine, Steven M., Gill, Steven R., Falush, Daniel, Blaser, Martin J.

Helicobacter pylori are gram-negative bacteria notable for their high level of genetic diversity and plasticity, features that may play a key role in the organism's ability to colonize the human...

Bacterial Community in the Crop of the Hoatzin, a Neotropical Folivorous Flying Bird▿ †

Godoy-Vitorino, Filipa, Ley, Ruth E., Gao, Zhan, Pei, Zhiheng, Ortiz-Zuazaga, Humberto, Pericchi, Luis R., ...

The hoatzin is unique among known avian species because of the fermentative function of its enlarged crop. A small-bodied flying foregut fermenter is a paradox, and this bird provides an interesting...

Leptin and Ghrelin in Relation to Helicobacter pylori Status in Adult Males

Roper, Jatin, Francois, Fritz, Shue, Peter L., Mourad, Michelle S., Pei, Zhiheng, Olivares De Perez, Asalia Z., ...

Context: Leptin and ghrelin, hormones involved in human energy homeostasis, are both produced in the stomach.

Molecular Analysis of Sarcoidosis Tissues for Mycobacterium Species DNA

Drake, Wonder Puryear, Pei, Zhiheng, Pride, David T., Collins, Robert D., Cover, Timothy L., Blaser, Martin J.

We performed polymerase chain reaction analysis, for Mycobacterium species 16S rRNA, rpoB, and IS6110 sequences, on 25 tissue specimens from patients with sarcoidosis and on 25 control tissue...