scholarly journals Riboflavin Biosynthesis Is Associated with Assimilatory Ferric Reduction and Iron Acquisition by Campylobacter jejuni

2007 ◽  
Vol 73 (24) ◽  
pp. 7819-7825 ◽  
Author(s):  
Rachel A. Crossley ◽  
Duncan J. H. Gaskin ◽  
Kathryn Holmes ◽  
Francis Mulholland ◽  
Jerry M. Wells ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Iron Uptake ◽  
Type Strain ◽  
Wild Type Strain ◽  
Iron Acquisition ◽  
Flavin Mononucleotide ◽  
Riboflavin Biosynthesis ◽  
Wild Type ◽  
Low Oxygen ◽  
Riboflavin Production

ABSTRACT One of the pathways involved in the acquisition of the essential metal iron by bacteria involves the reduction of insoluble Fe3+ to soluble Fe2+, followed by transport of Fe2+ to the cytoplasm. Flavins have been implicated as electron donors in this poorly understood process. Ferrous iron uptake is essential for intestinal colonization by the important pathogen Campylobacter jejuni and may be of particular importance under low-oxygen conditions. In this study, the links among riboflavin biosynthesis, ferric reduction, and iron acquisition in C. jejuni NCTC11168 have been investigated. A riboflavin auxotroph was generated by inactivation of the ribB riboflavin biosynthesis gene (Cj0572), and the resulting isogenic ribB mutant only grew in the presence of exogenous riboflavin or the riboflavin precursor diacetyl but not in the presence of the downstream products flavin adenine dinucleotide and flavin mononucleotide. Riboflavin uptake was unaffected in the ribB mutant under iron-limited conditions but was lower in both the wild-type strain and the ribB mutant under iron-replete conditions. Mutation of the fur gene, which encodes an iron uptake regulator of C. jejuni, resulted in an increase in riboflavin uptake which was independent of the iron content of the medium, suggesting a role for Fur in the regulation of the as-yet-unknown riboflavin transport system. Finally, ferric reduction activity was independent of iron availability in the growth medium but was lowered in the ribB mutant compared to the wild-type strain and, conversely, increased in the fur mutant. Taken together, the findings confirm close relationships among iron acquisition, riboflavin production, and riboflavin uptake in C. jejuni.

scholarly journals A Plasmid-Encoded FetMP-Fls Iron Uptake System Confers Selective Advantages to Salmonella enterica Serovar Typhimurium in Growth under Iron-Restricted Conditions and for Infection of Mammalian Host Cells

2020 ◽  
Vol 8 (5) ◽  
pp. 630
Author(s):  
Vanesa García ◽  
Ana Herrero-Fresno ◽  
Rosaura Rodicio ◽  
Alfonso Felipe-López ◽  
Ignacio Montero ◽  
...  
Keyword(s):  
Iron Content ◽  
Salmonella Enterica ◽  
Iron Uptake ◽  
Type Strain ◽  
Wild Type Strain ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Iron Acquisition ◽  
Clinical Strain ◽  
Wild Type ◽  
Serovar Typhimurium

The resistance plasmid pUO-StVR2, derived from virulence plasmid pSLT, is widespread in clinical isolates of Salmonella enterica serovar Typhimurium recovered in Spain and other European countries. pUO-StVR2 carries several genes encoding a FetMP-Fls system, which could be involved in iron uptake. We therefore analyzed S. Typhimurium LSP 146/02, a clinical strain selected as representative of the isolates carrying the plasmid, and an otherwise isogenic mutant lacking four genes (fetMP-flsDA) of the fetMP-fls region. Growth curves and determination of the intracellular iron content under iron-restricted conditions demonstrated that deletion of these genes impairs iron acquisition. Thus, under these conditions, the mutant grew significantly worse than the wild-type strain, its iron content was significantly lower, and it was outcompeted by the wild-type strain in competition assays. Importantly, the strain lacking the fetMP-flsDA genes was less invasive in cultured epithelial HeLa cells and replicated poorly upon infection of RAW264.7 macrophages. The genes were introduced into S. Typhimurium ATCC 14028, which lacks the FetMP-Fls system, and this resulted in increased growth under iron limitation as well as an increased ability to multiply inside macrophages. These findings indicate that the FetMP-Fls iron acquisition system exceeds the benefits conferred by the other high-affinity iron uptake systems carried by ATCC 14028 and LSP 146/02. We proposed that effective iron acquisition by this system in conjunction with antimicrobial resistance encoded from the same plasmid have greatly contributed to the epidemic success of S. Typhimurium isolates harboring pUO-StVR2.

scholarly journals Major Role for FeoB in Campylobacter jejuni Ferrous Iron Acquisition, Gut Colonization, and Intracellular Survival

2006 ◽  
Vol 74 (10) ◽  
pp. 5433-5444 ◽  
Author(s):  
Hemant Naikare ◽  
Kiran Palyada ◽  
Roger Panciera ◽  
Denver Marlow ◽  
Alain Stintzi
Keyword(s):  
Campylobacter Jejuni ◽  
Ferrous Iron ◽  
Type Strain ◽  
Wild Type Strain ◽  
Iron Acquisition ◽  
Space Versus ◽  
Pcr Analysis ◽  
Wild Type ◽  
Ileal Loop ◽  
Gut Colonization

ABSTRACT To assess the importance of ferrous iron acquisition in Campylobacter physiology and pathogenesis, we disrupted and characterized the Fe2+ iron transporter, FeoB, in Campylobacter jejuni NCTC 11168, 81-176, and ATCC 43431. The feoB mutant was significantly affected in its ability to transport 55Fe2+. It accumulated half the amount of iron than the wild-type strain during growth in an iron-containing medium. The intracellular iron of the feoB mutant was localized in the periplasmic space versus the cytoplasm for the wild-type strain. These results indicate that the feoB gene of C. jejuni encodes a functional ferrous iron transport system. Reverse transcriptase PCR analysis revealed the cotranscription of feoB and Cj1397, which encodes a homolog of Escherichia coli feoA. C. jejuni 81-176 feoB mutants exhibited reduced ability to persist in human INT-407 embryonic intestinal cells and porcine IPEC-1 small intestinal epithelial cells compared to the wild type. C. jejuni NCTC 11168 feoB mutant was outcompeted by the wild type for colonization and/or survival in the rabbit ileal loop. The feoB mutants of the three C. jejuni strains were significantly affected in their ability to colonize the chick cecum. And finally, the three feoB mutants were outcompeted by their respective wild-type strains for infection of the intestinal tracts of colostrum-deprived piglets. Taken together, these results demonstrate that FeoB-mediated ferrous iron acquisition contributes significantly to colonization of the gastrointestinal tract during both commensal and infectious relationship, and thus it plays an important role in Campylobacter pathogenesis.

scholarly journals Campylobacter jejuni FlpA Binds Fibronectin and Is Required for Maximal Host Cell Adherence

2009 ◽  
Vol 192 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Michael E. Konkel ◽  
Charles L. Larson ◽  
Rebecca C. Flanagan
Keyword(s):  
Amino Acids ◽  
Epithelial Cells ◽  
Campylobacter Jejuni ◽  
Type Strain ◽  
Wild Type Strain ◽  
Major Constituent ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Wild Type ◽  
Type Iii

ABSTRACT Campylobacter jejuni is one of the most frequent bacterial causes of food-borne gastrointestinal disease in developed countries. Previous work indicates that the binding of C. jejuni to human intestinal cells is crucial for host colonization and disease. Fibronectin (Fn), a major constituent of the extracellular matrix, is a ∼250-kDa glycoprotein present at regions of cell-to-cell contact in the intestinal epithelium. Fn is composed of three types of repeating units: type I (∼45 amino acids), type II (∼60 amino acids), and type III (∼90 amino acids). The deduced amino acid sequence of C. jejuni flpA (Cj1279c) contains at least three Fn type III domains. Based on the presence of the Fn type III domains, we hypothesized that FlpA contributes to the binding of C. jejuni to human INT 407 epithelial cells and Fn. We assessed the contribution of FlpA in C. jejuni binding to host cells by in vitro adherence assays with a C. jejuni wild-type strain and a C. jejuni flpA mutant and binding of purified FlpA protein to Fn by enzyme-linked immunosorbent assay (ELISA). Adherence assays revealed the binding of the C. jejuni flpA mutant to INT 407 epithelial cells was significantly reduced compared with that for a wild-type strain. In addition, rabbit polyclonal serum generated against FlpA blocked C. jejuni adherence to INT 407 cells in a concentration-dependent manner. Binding of FlpA to Fn was found to be dose dependent and saturable by ELISA, demonstrating the specificity of the interaction. Based on these data, we conclude that FlpA mediates C. jejuni attachment to host epithelial cells via Fn binding.

scholarly journals Mutation of waaC, Encoding Heptosyltransferase I in Campylobacter jejuni 81-176, Affects the Structure of both Lipooligosaccharide and Capsular Carbohydrate

2006 ◽  
Vol 188 (9) ◽  
pp. 3273-3279 ◽  
Author(s):  
Margaret I. Kanipes ◽  
Erzsebet Papp-Szabo ◽  
Patricia Guerry ◽  
Mario A. Monteiro
Keyword(s):  
Campylobacter Jejuni ◽  
Type Strain ◽  
Insertional Mutagenesis ◽  
Lipid A ◽  
Wild Type Strain ◽  
Capsular Polysaccharide ◽  
Resonance Spectroscopy ◽  
Gas Liquid Chromatography ◽  
Wild Type ◽  
Isolation And Characterization

ABSTRACT Campylobacter jejuni 81-176 lipooligosaccharide (LOS) is composed of two covalently linked domains: lipid A, a hydrophobic anchor, and a nonrepeating core oligosaccharide, consisting of an inner and outer core region. We report the isolation and characterization of the deepest rough C. jejuni 81-176 mutant by insertional mutagenesis into the waaC gene, encoding heptosyltransferase I that catalyzes the transfer of the first l-glycero-d-manno-heptose residue to 3-deoxy-d-manno-octulosonic residue (Kdo)-lipid A. Tricine gel electrophoresis, followed by silver staining, showed that site-specific mutation in the waaC gene resulted in the expression of a severely truncated LOS compared to wild-type strain 81-176. Gas-liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy showed that the waaC LOS species lacked all sugars distal to Kdo-lipid A. Parallel structural studies of the capsular polysaccharides of the wild-type strain 81-176 and waaC mutant revealed loss of the 3-O-methyl group in the waaC mutant. Complementation of the C. jejuni mutant by insertion of the wild-type C. jejuni waaC gene into a chromosomal locus resulted in LOS and capsular structures identical to those expressed in the parent strain. We also report here the presence of O-methyl phosphoramidate in wild-type strain 81-176 capsular polysaccharide.

scholarly journals The galE Gene of Campylobacter jejuni Is Involved in Lipopolysaccharide Synthesis and Virulence

2000 ◽  
Vol 68 (5) ◽  
pp. 2594-2601 ◽  
Author(s):  
Benjamin N. Fry ◽  
Shi Feng ◽  
Yuen-Yuen Chen ◽  
Diane G. Newell ◽  
Peter J. Coloe ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Parent Strain ◽  
Type Strain ◽  
Essential Role ◽  
Lipid A ◽  
Wild Type Strain ◽  
Gram Negative Bacteria ◽  
Wild Type ◽  
Gram Negative ◽  
Important Virulence Factor

ABSTRACT Lipopolysaccharide (LPS) is one of the main virulence factors of gram-negative bacteria. The LPS from Campylobacter spp. has endotoxic properties and has been shown to play a role in adhesion. We previously cloned a gene cluster (wla) which is involved in the synthesis of the Campylobacter jejuni 81116 LPS molecule. Sequence alignment of the first gene in this cluster indicated similarity with galE genes. These genes encode a UDP-glucose 4-epimerase, which catalyzes the interconversion of UDP-galactose and UDP-glucose. A Salmonella galE mutant was transformed with the galE gene from C. jejuni. The LPS analysis of wild-type, galE, and complementedgalE Salmonella strains showed that the C. jejuni galE gene could restore the smooth wild-typeSalmonella LPS. A UDP-glucose 4-epimerase assay was used to demonstrate that the galE gene from C. jejuniencoded this epimerase. We constructed a C. jejuni galEmutant which expressed a lipid A-core molecule of reduced molecular weight that did not react with antiserum raised against the parental strain. These results show an essential role for the galEgene in the synthesis of C. jejuni LPS. ThegalE mutant also showed a reduction in its ability to adhere to and invade INT407 cells. However, it was still able to colonize chickens to the same level as the wild-type strain. The serum resistance and hemolytic activity of this mutant were not changed compared to the parent strain. The ability of the mutant to take up DNA and integrate it in its genome was reduced 20-fold. These results show that LPS of C. jejuni is an important virulence factor.

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.

scholarly journals Identification of a Novel Membrane Transporter Mediating Resistance to Organic Arsenic in Campylobacter jejuni

2014 ◽  
Vol 58 (4) ◽  
pp. 2021-2029 ◽  
Author(s):  
Zhangqi Shen ◽  
Taradon Luangtongkum ◽  
Zhiyi Qiang ◽  
Byeonghwa Jeon ◽  
Liping Wang ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Type Strain ◽  
Wild Type Strain ◽  
Inorganic Arsenic ◽  
Feed Additive ◽  
Membrane Transporter ◽  
Wild Type ◽  
Arsenic Resistance ◽  
Content Type ◽  
Organic Arsenic

ABSTRACTAlthough bacterial mechanisms involved in the resistance to inorganic arsenic are well understood, the molecular basis for organic arsenic resistance has not been described.Campylobacter jejuni, a major food-borne pathogen causing gastroenteritis in humans, is highly prevalent in poultry and is reportedly resistant to the arsenic compound roxarsone (4-hydroxy-3-nitrobenzenearsonic acid), which has been used as a feed additive in the poultry industry for growth promotion. In this study, we report the identification of a novel membrane transporter (named ArsP) that contributes to organic arsenic resistance inCampylobacter. ArsP is predicted to be a membrane permease containing eight transmembrane helices, distinct from other known arsenic transporters. Analysis of multipleC. jejuniisolates from various animal species revealed that the presence of an intactarsPgene is associated with elevated resistance to roxarsone. In addition, inactivation ofarsPinC. jejuniresulted in 4- and 8-fold reductions in the MICs of roxarsone and nitarsone, respectively, compared to that for the wild-type strain. Furthermore, cloning ofarsPinto aC. jejunistrain lacking a functionalarsPgene led to 16- and 64-fold increases in the MICs of roxarsone and nitarsone, respectively. Neither mutation nor overexpression ofarsPaffected the MICs of inorganic arsenic, including arsenite and arsenate, inCampylobacter. Moreover, acquisition ofarsPin NCTC 11168 led to accumulation of less roxarsone than the wild-type strain lackingarsP. Together, these results indicate that ArsP functions as an efflux transporter specific for extrusion of organic arsenic and contributes to the resistance to these compounds inC. jejuni.

scholarly journals The Campylobacter jejuni Response Regulator, CbrR, Modulates Sodium Deoxycholate Resistance and Chicken Colonization

2005 ◽  
Vol 187 (11) ◽  
pp. 3662-3670 ◽  
Author(s):  
Brian H. Raphael ◽  
Sonia Pereira ◽  
Gary A. Flom ◽  
Qijing Zhang ◽  
Julian M. Ketley ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Histidine Kinase ◽  
Bile Salts ◽  
Type Strain ◽  
Target Genes ◽  
Wild Type Strain ◽  
Response Regulator ◽  
Sodium Deoxycholate ◽  
Wild Type ◽  
Bile Resistance

ABSTRACT Two-component regulatory systems play a major role in the physiological response of bacteria to environmental stimuli. Such systems are composed of a sensor histidine kinase and a response regulator whose ultimate function is to affect the expression of target genes. Response regulator mutants of Campylobacter jejuni strain F38011 were screened for sensitivity to sodium deoxycholate. A mutation in Cj0643, which encodes a response regulator with no obvious cognate histidine kinase, resulted in an absence of growth on plates containing a subinhibitory concentration of sodium deoxcholate (1%, wt/vol). In broth cultures containing 0.05% (wt/vol) sodium deoxycholate, growth of the mutant was significantly inhibited compared to growth of the C. jejuni F38011 wild-type strain. Complementation of the C. jejuni cbrR mutant in trans restored growth in both broth and plate cultures supplemented with sodium deoxycholate. Based on the phenotype displayed by its mutation, we designated the gene corresponding to Cj0643 as cbrR (Campylobacter bile resistance regulator). While the MICs of a variety of bile salts and other detergents for the C. jejuni cbrR mutant were lower, no difference was noted in its sensitivity to antibiotics or osmolarity. Finally, chicken colonization studies demonstrated that the C. jejuni cbrR mutant had a reduced ability to colonize compared to the wild-type strain. These data support previous findings that bile resistance contributes to colonization of chickens and establish that the response regulator, CbrR, modulates resistance to bile salts in C. jejuni.

scholarly journals The Hydroxamate Siderophore Rhequichelin Is Required for Virulence of the Pathogenic Actinomycete Rhodococcus equi

2012 ◽  
Vol 80 (12) ◽  
pp. 4106-4114 ◽  
Author(s):  
Raúl Miranda-CasoLuengo ◽  
Garry B. Coulson ◽  
Aleksandra Miranda-CasoLuengo ◽  
José A. Vázquez-Boland ◽  
Mary K. Hondalus ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Iron Acquisition ◽  
Iron Chelator ◽  
Rhodococcus Equi ◽  
Wild Type ◽  
Content Type ◽  
Peptide Synthetase ◽  
Tailoring Enzymes

ABSTRACTWe previously showed that the facultative intracellular pathogenRhodococcus equiproduces a nondiffusible and catecholate-containing siderophore (rhequibactin) involved in iron acquisition during saprophytic growth. Here, we provide evidence that therhbABCDEcluster directs the biosynthesis of a hydroxamate siderophore, rhequichelin, that plays a key role in virulence. TherhbCgene encodes a nonribosomal peptide synthetase that is predicted to produce a tetrapeptide consisting ofN5-formyl-N5-hydroxyornithine, serine,N5-hydroxyornithine, andN5-acyl-N5-hydroxyornithine. The otherrhbgenes encode putative tailoring enzymes mediating modification of ornithine residues incorporated into the hydroxamate product of RhbC. Transcription ofrhbCwas upregulated during growth in iron-depleted medium, suggesting that it plays a role in iron acquisition. This was confirmed by deletion ofrhbCD, rendering the resulting strainR. equiSID2 unable to grow in the presence of the iron chelator 2,2-dipyridyl. Supernatant of the wild-type strain rescued the phenotype ofR. equiSID2. The importance of rhequichelin in virulence was highlighted by the rapid increase in transcription levels ofrhbCfollowing infection and the inability ofR. equiSID2 to grow within macrophages. Unlike the wild-type strain,R. equiSID2 was unable to replicatein vivoand was rapidly cleared from the lungs of infected mice. Rhequichelin is thus a key virulence-associated factor, although nonpathogenicRhodococcusspecies also appear to produce rhequichelin or a structurally closely related compound. Rhequichelin biosynthesis may therefore be considered an example of cooption of a core actinobacterial trait in the evolution ofR. equivirulence.

scholarly journals Critical Role of LuxS in the Virulence of Campylobacter jejuni in a Guinea Pig Model of Abortion

2011 ◽  
Vol 80 (2) ◽  
pp. 585-593 ◽  
Author(s):  
Paul Plummer ◽  
Orhan Sahin ◽  
Eric Burrough ◽  
Rachel Sippy ◽  
Kathy Mou ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Campylobacter Jejuni ◽  
Type Strain ◽  
Wild Type Strain ◽  
Critical Role ◽  
Wild Type ◽  
Direct Role ◽  
Content Type

ABSTRACTPrevious studies onCampylobacter jejunihave demonstrated the role of LuxS in motility, cytolethal distending toxin production, agglutination, and intestinal colonization; however, its direct involvement in virulence has not been reported. In this study, we demonstrate a direct role ofluxSin the virulence ofC. jejuniin two different animal hosts. The IA3902 strain, a highly virulent sheep abortion strain recently described by our laboratory, along with its isogenicluxSmutant andluxScomplement strains, was inoculated by the oral route into both a pregnant guinea pig virulence model and a chicken colonization model. In both cases, the IA3902luxSmutant demonstrated a complete loss of ability to colonize the intestinal tract. In the pregnant model, the mutant also failed to induce abortion, while the wild-type strain was highly abortifacient. Genetic complementation of theluxSgene fully restored the virulent phenotype in both models. Interestingly, when the organism was inoculated into guinea pigs by the intraperitoneal route, no difference in virulence (abortion induction) was observed between theluxSmutant and the wild-type strain, suggesting that the defect in virulence following oral inoculation is likely associated with a defect in colonization and/or translocation of the organism out of the intestine. These studies provide the first direct evidence that LuxS plays an important role in the virulence ofC. jejuniusing anin vivomodel of natural disease.

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