scholarly journals Campylobacter jejuni proteins Cj0952c and Cj0951c affect chemotactic behaviour towards formic acid and are important for invasion of host cells

Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 3123-3135 ◽  
Author(s):  
A. Malik Tareen ◽  
Javid Iqbal Dasti ◽  
Andreas E. Zautner ◽  
Uwe Groß ◽  
Raimond Lugert
Keyword(s):  
Formic Acid ◽  
Campylobacter Jejuni ◽  
Formate Dehydrogenase ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Industrialized Countries ◽  
Transposon Insertion ◽  
Food Borne ◽  
Strain Nctc ◽  
Chemotactic Behaviour

Campylobacter jejuni, an important food-borne bacterial pathogen in industrialized countries and in the developing world, is one of the major causes of bacterial diarrhoea. To identify genes which are important for the invasion of host cells by the pathogen, we screened altogether 660 clones of a transposon-generated mutant library based on the clinical C. jejuni isolate B2. Thereby, we identified a clone with a transposon insertion in gene cj0952c. As in the well-characterized C. jejuni strain NCTC 11168, the corresponding protein together with the gene product of the adjacent gene cj0951c consists of two transmembrane domains, a HAMP domain and a putative MCP domain, which together are thought to act as a chemoreceptor, designated Tlp7. In this report we show that genes cj0952c and cj0951c (i) are important for the host cell invasion of the pathogen, (ii) are not translated as one protein in C. jejuni isolate B2, contradicting the idea of a postulated read-through mechanism, (iii) affect the motility of C. jejuni, (iv) alter the chemotactic behaviour of the pathogen towards formic acid, and (v) are not related to the utilization of formic acid by formate dehydrogenase.

scholarly journals Transposon mutagenesis in a hyper-invasive clinical isolate of Campylobacter jejuni reveals a number of genes with potential roles in invasion

Microbiology ◽  
2010 ◽  
Vol 156 (4) ◽  
pp. 1134-1143 ◽  
Author(s):  
Muhammad Afzal Javed ◽  
Andrew J. Grant ◽  
Mary. C. Bagnall ◽  
Duncan J. Maskell ◽  
Diane G. Newell ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Campylobacter Jejuni ◽  
Transposon Mutagenesis ◽  
Genomic Variation ◽  
Host Cells ◽  
Transposon Insertion ◽  
Strain Nctc ◽  
Transposon Insertions

Transposon mutagenesis has been applied to a hyper-invasive clinical isolate of Campylobacter jejuni, 01/51. A random transposon mutant library was screened in an in vitro assay of invasion and 26 mutants with a significant reduction in invasion were identified. Given that the invasion potential of C. jejuni is relatively poor compared to other enteric pathogens, the use of a hyper-invasive strain was advantageous as it greatly facilitated the identification of mutants with reduced invasion. The location of the transposon insertion in 23 of these mutants has been determined; all but three of the insertions are in genes also present in the genome-sequenced strain NCTC 11168. Eight of the mutants contain transposon insertions in one region of the genome (∼14 kb), which when compared with the genome of NCTC 11168 overlaps with one of the previously reported plasticity regions and is likely to be involved in genomic variation between strains. Further characterization of one of the mutants within this region has identified a gene that might be involved in adhesion to host cells.

scholarly journals It takes two to tango: two TatA paralogues and two redox enzyme-specific chaperones are involved in the localization of twin-arginine translocase substrates in Campylobacter jejuni

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 2053-2066 ◽  
Author(s):  
Yang-Wei Liu ◽  
Andrew Hitchcock ◽  
Robert C. Salmon ◽  
David J. Kelly
Keyword(s):  
Nitrate Reductase ◽  
Campylobacter Jejuni ◽  
Formate Dehydrogenase ◽  
Specific Rate ◽  
Peptide Cleavage ◽  
Food Borne ◽  
Sulphite Oxidase ◽  
Strain Nctc ◽  
Electron Transport Chains ◽  
Twin Arginine Translocase

The food-borne zoonotic pathogen Campylobacter jejuni has complex electron transport chains required for growth in the host, many of which contain cofactored periplasmic enzymes localized by the twin-arginine translocase (TAT). We report here the identification of two paralogues of the TatA translocase component in C. jejuni strain NCTC 11168, encoded by cj1176c (tatA1) and cj0786 (tatA2). Deletion mutants constructed in either or both of the tatA1 and tatA2 genes displayed distinct growth and enzyme activity phenotypes. For sulphite oxidase (SorAB), the multi-copper oxidase (CueO) and alkaline phosphatase (PhoX), complete dependency on TatA1 for correct periplasmic activity was observed. However, the activities of nitrate reductase (NapA), formate dehydrogenase (FdhA) and trimethylamine N-oxide reductase (TorA) were significantly reduced in the tatA2 mutant. In contrast, the specific rate of fumarate reduction catalysed by the flavoprotein subunit of the methyl menaquinone fumarate reductase (MfrA) was similar in periplasmic fractions of both the tatA1 and the tatA2 mutants and only the deletion of both genes abolished activity. Nevertheless, unprocessed MfrA accumulated in the periplasm of the tatA1 (but not tatA2) mutant, indicating aberrant signal peptide cleavage. Surprisingly, TatA2 lacks two conserved residues (Gln8 and Phe39) known to be essential in Escherichia coli TatA and we suggest it is unable to function correctly in the absence of TatA1. Finally, only two TAT chaperones (FdhM and NapD) are encoded in strain NCTC 11168, which mutant studies confirmed are highly specific for formate dehydrogenase and nitrate reductase assembly, respectively. Thus, other TAT substrates must use general chaperones in their biogenesis.

scholarly journals The Potassium Transporter Trk and External Potassium Modulate Salmonella enterica Protein Secretion and Virulence

2008 ◽  
Vol 77 (2) ◽  
pp. 667-675 ◽  
Author(s):  
Jing Su ◽  
Hao Gong ◽  
Jeff Lai ◽  
Andrew Main ◽  
Sangwei Lu
Keyword(s):  
Salmonella Enterica ◽  
Bacterial Pathogen ◽  
Effector Proteins ◽  
Host Cells ◽  
Infection Model ◽  
Human Pathogens ◽  
Food Borne ◽  
External Potassium ◽  
Living Organisms ◽  
External K

ABSTRACT Potassium (K+) is the most abundant intracellular cation and is essential for many physiological functions of all living organisms; however, its role in the pathogenesis of human pathogens is not well understood. In this study, we characterized the functions of the bacterial Trk K+ transport system and external K+ in the pathogenesis of Salmonella enterica, a major food-borne bacterial pathogen. Here we report that Trk is important for Salmonella to invade and grow inside epithelial cells. It is also necessary for the full virulence of Salmonella in an animal infection model. Analysis of proteins of Salmonella indicated that Trk is involved in the expression and secretion of effector proteins of the type III secretion system (TTSS) encoded by Salmonella pathogenicity island 1 (SPI1) that were previously shown to be necessary for Salmonella invasion. In addition to the role of the Trk transporter in the pathogenesis of Salmonella, we discovered that external K+ modulates the pathogenic properties of Salmonella by increasing the expression and secretion of effector proteins of the SPI1-encoded TTSS and by enhancing epithelial cell invasion. Our studies demonstrated that K+ is actively involved in the pathogenesis of Salmonella and indicated that Salmonella may take advantage of the high K+ content inside host cells and in the intestinal fluid during diarrhea to become more virulent.

scholarly journals A truncated haemoglobin implicated in oxygen metabolism by the microaerophilic food-borne pathogen Campylobacter jejuni

Microbiology ◽  
2005 ◽  
Vol 151 (12) ◽  
pp. 4079-4091 ◽  
Author(s):  
Laura M. Wainwright ◽  
Karen T. Elvers ◽  
Simon F. Park ◽  
Robert K. Poole
Keyword(s):  
Campylobacter Jejuni ◽  
Nitrosative Stress ◽  
Bacterial Pathogen ◽  
Oxygen Metabolism ◽  
Wild Type ◽  
Gene Encoding ◽  
Food Borne ◽  
Micro Organisms ◽  
Mutant Cells ◽  
Kinetics Of

Of the three groups of haemoglobins identified in micro-organisms (single-domain globins, flavohaemoglobins and truncated globins), the last group is the least well understood. The function of the truncated haemoglobin (Ctb) encoded by Cj0465c in the microaerophilic food-borne bacterial pathogen Campylobacter jejuni was investigated by constructing a ctb mutant and characterizing its phenotype. The effects of the ctb mutation on the kinetics of terminal oxidase function in C. jejuni were investigated using oxyleghaemoglobin and oxymyoglobin as sensitive reporters of O2 consumption. The V max of ctb mutant cells for O2, calculated using either globin, was greater than that of wild-type cells at extracellular O2 concentrations up to ∼1 μM, suggesting a role for Ctb in moderating O2 supply for reduction by high-affinity terminal oxidases. However, cells mutated in ctb were disadvantaged when grown under conditions of high aeration, as revealed by measurements of growth yields and rates in batch culture. Furthermore, the rate at which ctb mutant cells consumed O2 in an O2 electrode (10–200 μM O2) was approximately half the rate displayed by wild-type cells, reflecting a role for Ctb in respiration at physiologically relevant external O2 concentrations. However, a lack of sensitivity of the mutant to paraquat or H2O2 indicated that increased oxidative stress under such conditions was not the cause of these phenotypes. O2 affinities of cells (K m values of approximately 40 nM and 1 μM) were unaffected by mutation of either Ctb or the full-length C. jejuni globin, Cgb. Although the gene encoding Ctb was found to be upregulated by S-nitrosoglutathione (GSNO) and the NO-donating compound S-nitroso-N-acetylpenicillamine (SNAP), a ctb mutant did not display sensitivity to a number of nitrosative stress-generating compounds. The authors conclude that Ctb is involved in moderating O2 flux within C. jejuni.

scholarly journals Energy Taxis Drives Campylobacter jejuni toward the Most Favorable Conditions for Growth

2009 ◽  
Vol 75 (16) ◽  
pp. 5308-5314 ◽  
Author(s):  
Christina S. Vegge ◽  
Lone Brøndsted ◽  
Yi-Ping Li ◽  
Dang D. Bang ◽  
Hanne Ingmer
Keyword(s):  
Campylobacter Jejuni ◽  
Carbon Sources ◽  
Bacterial Pathogen ◽  
Host Interaction ◽  
Energy Taxis ◽  
Food Borne ◽  
Embryo Cells ◽  
Chemical Conditions ◽  
Favorable Conditions ◽  
Developed World

ABSTRACT Campylobacter jejuni is a serious food-borne bacterial pathogen in the developed world. Poultry is a major reservoir, and C. jejuni appears highly adapted to the gastrointestinal tract of birds. Several factors are important for chicken colonization and virulence, including a taxis mechanism for environmental navigation. To explore the mechanism of chemotaxis in C. jejuni, we constructed mutants with deletions of five putative mcp (methyl-accepting chemotaxis protein) genes (tlp1, tlp2, tlp3, docB, and docC). Surprisingly, the deletions did not affect the chemotactic behavior of the mutants compared to that of the parental strain. However, the tlp1, tlp3, docB, and docC mutant strains displayed a 10-fold decrease in the ability to invade human epithelial and chicken embryo cells, hence demonstrating that the corresponding proteins affect the host interaction. l-Asparagine, formate, d-lactate, and chicken mucus were identified as new attractants of C. jejuni, and we observed that chemical substances promoting tactic attraction are all known to support the growth of this organism. The attractants could be categorized as carbon sources and electron donors and acceptors, and we furthermore observed a correlation between an attractant's potency and its efficiency as an energy source. The tactic attraction was inhibited by the respiratory inhibitors HQNO (2-n-heptyl-4-hydroxyquinoline N-oxide) and sodium azide, which significantly reduce energy production by oxidative phosphorylation. These findings strongly indicate that energy taxis is the primary force in environmental navigation by C. jejuni and that this mechanism drives the organism toward the optimal chemical conditions for energy generation and colonization.

scholarly journals Complete Genome Sequence ofCampylobacter jejuniRM1285, a Rod-Shaped Morphological Variant

2015 ◽  
Vol 3 (6) ◽  
Author(s):  
Nereus W. Gunther ◽  
James L. Bono ◽  
David S. Needleman
Keyword(s):  
Campylobacter Jejuni ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Bacterial Pathogen ◽  
Gram Negative ◽  
Morphological Variant ◽  
Poultry Products ◽  
Food Borne

Campylobacter jejuniis a spiral shaped Gram-negative food-borne bacterial pathogen of humans found on poultry products. Strain RM1285 is a rod-shaped variant of this species. The genome of RM1285 was determined to be 1,635,803 bp, with a G+C content of 30.5%.

scholarly journals The Campylobacter jejuni CiaD effector co-opts the host cell protein IQGAP1 to promote cell entry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nicholas M. Negretti ◽  
Christopher R. Gourley ◽  
Prabhat K. Talukdar ◽  
Geremy Clair ◽  
Courtney M. Klappenbach ◽  
...  
Keyword(s):  
Host Cell ◽  
Campylobacter Jejuni ◽  
Foodborne Pathogen ◽  
Small Gtpase ◽  
Host Cells ◽  
Cell Protein ◽  
Host Cell Protein ◽  
Cell Binding ◽  
Actin Reorganization ◽  
Cell Cytosol

AbstractCampylobacter jejuni is a foodborne pathogen that binds to and invades the epithelial cells lining the human intestinal tract. Maximal invasion of host cells by C. jejuni requires cell binding as well as delivery of the Cia proteins (Campylobacter invasion antigens) to the host cell cytosol via the flagellum. Here, we show that CiaD binds to the host cell protein IQGAP1 (a Ras GTPase-activating-like protein), thus displacing RacGAP1 from the IQGAP1 complex. This, in turn, leads to the unconstrained activity of the small GTPase Rac1, which is known to have roles in actin reorganization and internalization of C. jejuni. Our results represent the identification of a host cell protein targeted by a flagellar secreted effector protein and demonstrate that C. jejuni-stimulated Rac signaling is dependent on IQGAP1.

The structures of the lipooligosaccharide and capsule polysaccharide of Campylobacter jejuni genome sequenced strain NCTC 11168

2002 ◽  
Vol 269 (21) ◽  
pp. 5119-5136 ◽  
Author(s):  
Frank St. Michael ◽  
Christine M. Szymanski ◽  
Jianjun Li ◽  
Kenneth H. Chan ◽  
Nam Huan Khieu ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Strain Nctc

Enhancement of formic acid production from CO2 in formate dehydrogenase reaction using nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109978-109982 ◽  
Author(s):  
Young-Kee Kim ◽  
Sung-Yeob Lee ◽  
Byung-Keun Oh
Keyword(s):  
Mass Transfer ◽  
Formic Acid ◽  
Acid Production ◽  
Transfer Rate ◽  
Formate Dehydrogenase ◽  
Mass Transfer Rate ◽  
Liquid Mass ◽  
Dehydrogenase Reaction ◽  
Liquid Mass Transfer ◽  
Mesoporous Nanoparticles

In an enzyme process using a gas substrate, the enhanced gas liquid mass transfer rate of the gas substrate by methyl-functionalized mesoporous nanoparticles could improve the productivity.

scholarly journals The Listeria monocytogenes hemolysin has an acidic pH optimum to compartmentalize activity and prevent damage to infected host cells

2002 ◽  
Vol 156 (6) ◽  
pp. 1029-1038 ◽  
Author(s):  
Ian J. Glomski ◽  
Margaret M. Gedde ◽  
Albert W. Tsang ◽  
Joel A. Swanson ◽  
Daniel A. Portnoy
Keyword(s):  
Listeria Monocytogenes ◽  
Bacterial Pathogen ◽  
Cytolytic Activity ◽  
Host Cells ◽  
Adaptive Mutation ◽  
Acidic Ph ◽  
Listeriolysin O ◽  
Lysosomal Hydrolases ◽  
Ph Optimum ◽  
Neutral Ph

Listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a phagosome and grows in the host cell cytosol. The pore-forming cholesterol-dependent cytolysin, listeriolysin O (LLO), mediates bacterial escape from vesicles and is ∼10-fold more active at an acidic than neutral pH. By swapping dissimilar residues from a pH-insensitive orthologue, perfringolysin O (PFO), we identified leucine 461 as unique to pathogenic Listeria and responsible for the acidic pH optimum of LLO. Conversion of leucine 461 to the threonine present in PFO increased the hemolytic activity of LLO almost 10-fold at a neutral pH. L. monocytogenes synthesizing LLO L461T, expressed from its endogenous site on the bacterial chromosome, resulted in a 100-fold virulence defect in the mouse listeriosis model. These bacteria escaped from acidic phagosomes and initially grew normally in cells and spread cell to cell, but prematurely permeabilized the host membrane and killed the cell. These data show that the acidic pH optimum of LLO results from an adaptive mutation that acts to limit cytolytic activity to acidic vesicles and prevent damage in the host cytosol, a strategy also used by host cells to compartmentalize lysosomal hydrolases.

Sign in / Sign up

Export Citation Format

Share Document