scholarly journals Role of Campylobacter jejuni Respiratory Oxidases and Reductases in Host Colonization

2008 ◽  
Vol 74 (5) ◽  
pp. 1367-1375 ◽  
Author(s):  
Rebecca A. Weingarten ◽  
Jesse L. Grimes ◽  
Jonathan W. Olson
Keyword(s):  
Campylobacter Jejuni ◽  
Anaerobic Respiration ◽  
Wild Type ◽  
Respiratory Enzymes ◽  
Host Colonization ◽  
Enzymatic Function ◽  
Food Borne ◽  
Transport Chain ◽  
Respiratory Oxidases

ABSTRACT Campylobacter jejuni is the leading cause of human food-borne bacterial gastroenteritis. The C. jejuni genome sequence predicts a branched electron transport chain capable of utilizing multiple electron acceptors. Mutants were constructed by disrupting the coding regions of the respiratory enzymes nitrate reductase (napA::Cm), nitrite reductase (nrfA::Cm), dimethyl sulfoxide, and trimethylamine N-oxide reductase (termed Cj0264::Cm) and the two terminal oxidases, a cyanide-insensitive oxidase (cydA::Cm) and cbb3-type oxidase (ccoN::Cm). Each strain was characterized for the loss of the associated enzymatic function in vitro. The strains were then inoculated into 1-week-old chicks, and the cecal contents were assayed for the presence of C. jejuni 2 weeks postinoculation. cydA::Cm and Cj0264c::Cm strains colonized as well as the wild type; napA::Cm and nrfA::Cm strains colonized at levels significantly lower than the wild type. The ccoN::Cm strain was unable to colonize the chicken; no colonies were recovered at the end of the experiment. While there appears to be a role for anaerobic respiration in host colonization, oxygen is the most important respiratory acceptor for C. jejuni in the chicken cecum.

Metabolite and transcriptome analysis of Campylobacter jejuni in vitro growth reveals a stationary-phase physiological switch

Microbiology ◽  
2009 ◽  
Vol 155 (1) ◽  
pp. 80-94 ◽  
Author(s):  
John A. Wright ◽  
Andrew J. Grant ◽  
Douglas Hurd ◽  
Marcus Harrison ◽  
Edward J. Guccione ◽  
...  
Keyword(s):  
Amino Acid ◽  
Stationary Phase ◽  
Campylobacter Jejuni ◽  
Growth Cycle ◽  
Video Tracking ◽  
Acetate Excretion ◽  
Food Borne ◽  
Amino Acid Utilization ◽  
Switch Mechanism

Campylobacter jejuni is a prevalent cause of food-borne diarrhoeal illness in humans. Understanding of the physiological and metabolic capabilities of the organism is limited. We report a detailed analysis of the C. jejuni growth cycle in batch culture. Combined transcriptomic, phenotypic and metabolic analysis demonstrates a highly dynamic ‘stationary phase’, characterized by a peak in motility, numerous gene expression changes and substrate switching, despite transcript changes that indicate a metabolic downshift upon the onset of stationary phase. Video tracking of bacterial motility identifies peak activity during stationary phase. Amino acid analysis of culture supernatants shows a preferential order of amino acid utilization. Proton NMR (1H-NMR) highlights an acetate switch mechanism whereby bacteria change from acetate excretion to acetate uptake, most probably in response to depletion of other substrates. Acetate production requires pta (Cj0688) and ackA (Cj0689), although the acs homologue (Cj1537c) is not required. Insertion mutants in Cj0688 and Cj0689 maintain viability less well during the stationary and decline phases of the growth cycle than wild-type C. jejuni, suggesting that these genes, and the acetate pathway, are important for survival.

scholarly journals The Polysaccharide Capsule of Campylobacter jejuni Modulates the Host Immune Response

2012 ◽  
Vol 81 (3) ◽  
pp. 665-672 ◽  
Author(s):  
Alexander C. Maue ◽  
Krystle L. Mohawk ◽  
David K. Giles ◽  
Frédéric Poly ◽  
Cheryl P. Ewing ◽  
...  
Keyword(s):  
Immune Response ◽  
Campylobacter Jejuni ◽  
Diarrheal Disease ◽  
Host Immune Response ◽  
Interleukin 17 ◽  
Wild Type ◽  
Content Type ◽  
Polysaccharide Capsule ◽  
Colonization Model

ABSTRACTCampylobacter jejuniis a major cause of bacterial diarrheal disease worldwide. The organism is characterized by a diversity of polysaccharide structures, including a polysaccharide capsule. MostC. jejunicapsules are known to be decorated nonstoichiometrically with methyl phosphoramidate (MeOPN). The capsule ofC. jejuni81-176 has been shown to be required for serum resistance, but here we show that an encapsulated mutant lacking the MeOPN modification, anmpnCmutant, was equally as sensitive to serum killing as the nonencapsulated mutant. A nonencapsulated mutant, akpsMmutant, exhibited significantly reduced colonization compared to that of wild-type 81-176 in a mouse intestinal colonization model, and thempnCmutant showed an intermediate level of colonization. Both mutants were associated with higher levels of interleukin 17 (IL-17) expression from lamina propria CD4+cells than from cells from animals infected with 81-176. In addition, reduced levels of Toll-like receptor 4 (TLR4) and TLR2 activation were observed followingin vitrostimulation of human reporter cell lines with thekpsMandmpnCmutants compared to those with wild-type 81-176. The data suggest that the capsule polysaccharide ofC. jejuniand the MeOPN modification modulate the host immune response.

scholarly journals Autoinducer-2 Production in Campylobacter jejuni Contributes to Chicken Colonization

2008 ◽  
Vol 75 (1) ◽  
pp. 281-285 ◽  
Author(s):  
Beatriz Qui�ones ◽  
William G. Miller ◽  
Anna H. Bates ◽  
Robert E. Mandrell
Keyword(s):  
Gastrointestinal Tract ◽  
Epithelial Cells ◽  
Organic Acids ◽  
Campylobacter Jejuni ◽  
Hepatoma Cells ◽  
Lower Gastrointestinal Tract ◽  
Host Colonization ◽  
Autoinducer 2

ABSTRACT Inactivation of luxS, encoding an AI-2 biosynthesis enzyme, in Campylobacter jejuni strain 81-176 significantly reduced colonization of the chick lower gastrointestinal tract, chemotaxis toward organic acids, and in vitro adherence to LMH chicken hepatoma cells. Thus, AI-2 production in C. jejuni contributes to host colonization and interactions with epithelial cells.

scholarly journals Pancreatic Amylase Is an Environmental Signal for Regulation of Biofilm Formation and Host Interaction in Campylobacter jejuni

2015 ◽  
Vol 83 (12) ◽  
pp. 4884-4895 ◽  
Author(s):  
Waheed Jowiya ◽  
Katja Brunner ◽  
Sherif Abouelhadid ◽  
Haitham A. Hussain ◽  
Sean P. Nair ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Infection Model ◽  
Pancreatic Amylase ◽  
Content Type ◽  
Host Interaction ◽  
Food Borne ◽  
Epithelial Cell Lines

Campylobacter jejuniis a commensal bacterium in the intestines of animals and birds and a major cause of food-borne gastroenteritis in humans worldwide. Here we show that exposure to pancreatic amylase leads to secretion of an α-dextran byC. jejuniand that a secreted protease, Cj0511, is required. Exposure ofC. jejunito pancreatic amylase promotes biofilm formationin vitro, increases interaction with human epithelial cell lines, increases virulence in theGalleria mellonellainfection model, and promotes colonization of the chicken ileum. We also show that exposure to pancreatic amylase protectsC. jejunifrom stress conditionsin vitro, suggesting that the induced α-dextran may be important during transmission between hosts. This is the first evidence that pancreatic amylase functions as an interkingdom signal in an enteric microorganism.

scholarly journals The Dual-Functioning Fumarate Reductase Is the Sole Succinate:Quinone Reductase in Campylobacter jejuni and Is Required for Full Host Colonization

2009 ◽  
Vol 191 (16) ◽  
pp. 5293-5300 ◽  
Author(s):  
Rebecca A. Weingarten ◽  
Michael E. Taveirne ◽  
Jonathan W. Olson
Keyword(s):  
Organic Acids ◽  
Succinate Dehydrogenase ◽  
Campylobacter Jejuni ◽  
Growth Phase ◽  
Tca Cycle ◽  
Fumarate Reductase ◽  
Wild Type ◽  
Succinate Dehydrogenase Activity

ABSTRACT Campylobacter jejuni encodes all the enzymes necessary for a complete oxidative tricarboxylic acid (TCA) cycle. Because of its inability to utilize glucose, C. jejuni relies exclusively on amino acids as the source of reduced carbon, and they are incorporated into central carbon metabolism. The oxidation of succinate to fumarate is a key step in the oxidative TCA cycle. C. jejuni encodes enzymes annotated as a fumarate reductase (Cj0408 to Cj0410) and a succinate dehydrogenase (Cj0437 to Cj0439). Null alleles in the genes encoding each enzyme were constructed. Both enzymes contributed to the total fumarate reductase activity in vitro. The frdA::cat + strain was completely deficient in succinate dehydrogenase activity in vitro and was unable to perform whole-cell succinate-dependent respiration. The sdhA::cat + strain exhibited wild-type levels of succinate dehydrogenase activity both in vivo and in vitro. These data indicate that Frd is the only succinate dehydrogenase in C. jejuni and that the protein annotated as a succinate dehydrogenase has been misannotated. The frdA::cat + strain was also unable to grow with the characteristic wild-type biphasic growth pattern and exhibited only the first growth phase, which is marked by the consumption of aspartate, serine, and associated organic acids. Substrates consumed in the second growth phase (glutamate, proline, and associated organic acids) were not catabolized by the the frdA::cat + strain, indicating that the oxidation of succinate is a crucial step in metabolism of these substrates. Chicken colonization trials confirmed the in vivo importance of succinate oxidation, as the frdA::cat + strain colonized chickens at significantly lower levels than the wild type, while the sdhA::cat + strain colonized chickens at wild-type levels.

scholarly journals The Campylobacter jejuni NADH:Ubiquinone Oxidoreductase (Complex I) Utilizes Flavodoxin Rather than NADH

2007 ◽  
Vol 190 (3) ◽  
pp. 915-925 ◽  
Author(s):  
Dilan R. Weerakoon ◽  
Jonathan W. Olson
Keyword(s):  
Campylobacter Jejuni ◽  
Complex I ◽  
Nadh Dehydrogenase ◽  
Respiratory Activity ◽  
Essential Gene ◽  
Electron Flow ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
The Novel ◽  
Wild Type ◽  
Transport Chain

ABSTRACT Campylobacter jejuni encodes 12 of the 14 subunits that make up the respiratory enzyme NADH:ubiquinone oxidoreductase (also called complex I). The two nuo genes not present in C. jejuni encode the NADH dehydrogenase, and in their place in the operon are the novel genes designated Cj1575c and Cj1574c. A series of mutants was generated in which each of the 12 nuo genes (homologues to known complex I subunits) was disrupted or deleted. Each of the nuo mutants will not grow in amino acid-based medium unless supplemented with an alternative respiratory substrate such as formate. Unlike the nuo genes, Cj1574c is an essential gene and could not be disrupted unless an intact copy of the gene was provided at an unrelated site on the chromosome. A nuo deletion mutant can efficiently respire formate but is deficient in α-ketoglutarate respiratory activity compared to the wild type. In C. jejuni, α-ketoglutarate respiration is mediated by the enzyme 2-oxoglutarate:acceptor oxidoreductase; mutagenesis of this enzyme abolishes α-ketoglutarate-dependent O2 uptake and fails to reduce the electron transport chain. The electron acceptor for 2-oxoglutarate:acceptor oxidoreductase was determined to be flavodoxin, which was also determined to be an essential protein in C. jejuni. A model is presented in which CJ1574 mediates electron flow into the respiratory transport chain from reduced flavodoxin and through complex I.

scholarly journals In Vitro Transposition System for Efficient Generation of Random Mutants of Campylobacter jejuni

2001 ◽  
Vol 183 (7) ◽  
pp. 2384-2388 ◽  
Author(s):  
Oscar R. Colegio ◽  
Thomas J. Griffin ◽  
Nigel D. F. Grindley ◽  
Jorge E. Galán
Keyword(s):  
Campylobacter Jejuni ◽  
Bacterial Genome ◽  
The United States ◽  
Efficient System ◽  
Sigma 54 ◽  
Efficient Generation ◽  
Food Borne ◽  
Entire Nucleotide Sequence ◽  
Insertion Mutants

ABSTRACT Campylobacter jejuni is the most common cause of food-borne illnesses in the United States. Despite the fact that the entire nucleotide sequence of its genome has recently become available, its mechanisms of pathogenicity are poorly understood. This is in part due to the lack of an efficient mutagenesis system. Here we describe an in vitro transposon mutagenesis system based on theStaphylococcus aureus transposable element Tn552 that allows the efficient generation of insertion mutants of C. jejuni. Insertions occur randomly and throughout the entire bacterial genome. We have tested this system in the isolation of nonmotile mutants of C. jejuni. Demonstrating the utility of the system, six nonmotile mutants from a total of nine exhibited insertions in genes known to be associated with motility. An additional mutant had an inactivating insertion in sigma 54, implicating this transcription factor in flagellum regulation. The availability of this efficient system will greatly facilitate the study of the mechanisms of pathogenesis of this important pathogen.

scholarly journals Narrow-Spectrum Inhibitors of Campylobacter jejuni Flagellar Expression and Growth

2015 ◽  
Vol 59 (7) ◽  
pp. 3880-3886 ◽  
Author(s):  
Jeremiah G. Johnson ◽  
Caroline Yuhas ◽  
Thomas J. McQuade ◽  
Martha J. Larsen ◽  
Victor J. DiRita
Keyword(s):  
Small Molecules ◽  
Campylobacter Jejuni ◽  
Campylobacter Coli ◽  
Content Type ◽  
Food Borne ◽  
Food Borne Illness ◽  
Inhibitor Screen

ABSTRACTCampylobacter jejuniis a major cause of food-borne illness due to its ability to reside within the gastrointestinal tracts of chickens. Multiple studies have identified the flagella ofC. jejunias a major determinant of chicken colonization. An inhibitor screen of approximately 147,000 small molecules was performed to identify compounds that are able to inhibit flagellar expression in a reporter strain ofC. jejuni. Several compounds that modestly inhibited motility of wild-typeC. jejuniin standard assays were identified, as were a number of small molecules that robustly inhibitedC. jejunigrowth,in vitro. Examination of similar bacterial screens found that many of these small molecules inhibited only the growth ofC. jejuni. Follow-up assays demonstrated inhibition of other strains ofC. jejuniandCampylobacter colibut no inhibition of the closely relatedHelicobacter pylori. The compounds were determined to be bacteriostatic and nontoxic to eukaryotic cells. Preliminary results from a day-of-hatch chick model of colonization suggest that at least one of the compounds demonstrates promise for reducingCampylobactercolonization loadsin vivo, although further medicinal chemistry may be required to enhance bioavailability.

Free radical processes induced by desiccation in germinating maize. The relationship with respiration and loss of desiccation tolerance

1994 ◽  
Vol 102 ◽  
pp. 211-218 ◽  
Author(s):  
O. Leprince ◽  
G. A. F. Hendry ◽  
N. M. Atherton
Keyword(s):  
Free Radical ◽  
Desiccation Tolerance ◽  
Respiratory Enzymes ◽  
Stable Free Radical ◽  
Paramagnetic Resonance ◽  
Free Radical Processes ◽  
Transport Chain ◽  
Resonance Response ◽  
Radical Processes

SynopsisUsing germination of maize as a model, desiccation-induced free radical processes were studied with the object of understanding desiccation tolerance. Several significant elements of damage were observed in desiccated material associated with development of desiccation intolerance: increased lipid peroxidation, phospholipid de-esterification, build-up of a stable free radical, supression or repression of respiratory enzymes from complex I, II and IV. An EPR (electron paramagnetic resonance) response was also detected in isolated mitochondria following in vitro desiccation. The loss of desiccation tolerance appeared to be dependent on oxygen concentration. Two highly significant correlations were independently found between respiration rates and production of a stable free radical detected by EPR. These data suggest that respiration is an important factor in the loss of desiccation tolerance. We present a model suggesting that activated oxygen formation during desiccation originates in the disruption of the mitochondrial electron transport chain with increasing leakage to oxygen so generating irreversible and lethal peroxidative damage, leading to the development of desiccation intolerance.

scholarly journals A Deep-Rough Mutant of Campylobacter jejuni 81-176 Is Noninvasive for Intestinal Epithelial Cells

2004 ◽  
Vol 72 (4) ◽  
pp. 2452-2455 ◽  
Author(s):  
Margaret I. Kanipes ◽  
Lindsay C. Holder ◽  
Adrian T. Corcoran ◽  
Anthony P. Moran ◽  
Patricia Guerry
Keyword(s):  
Epithelial Cells ◽  
Campylobacter Jejuni ◽  
Type Strain ◽  
Wild Type Strain ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
Increased Sensitivity ◽  
Rough Mutant

ABSTRACT A waaF mutant of Campylobacter jejuni 81-176 showed decreased invasion of INT407 cells in vitro and increased sensitivity to some antibiotics compared to what was seen with the wild-type strain.

Sign in / Sign up

Export Citation Format

Share Document