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Castillo S, Heredia N, Arechiga-Carvajal E, García S. Citrus Extracts as Inhibitors of Quorum Sensing, Biofilm Formation and Motility ofCampylobacter jejuni. FOOD BIOTECHNOL 2014. [DOI: 10.1080/08905436.2014.895947] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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52
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Hwang S, Miller WG, Ryu S, Jeon B. Divergent distribution of the sensor kinase CosS in non-thermotolerant campylobacter species and its functional incompatibility with the response regulator CosR of Campylobacter jejuni. PLoS One 2014; 9:e89774. [PMID: 24587027 PMCID: PMC3938529 DOI: 10.1371/journal.pone.0089774] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 01/24/2014] [Indexed: 11/18/2022] Open
Abstract
Two-component signal transduction systems are commonly composed of a sensor histidine kinase and a cognate response regulator, modulating gene expression in response to environmental changes through a phosphorylation-dependent process. CosR is an OmpR-type response regulator essential for the viability of Campylobacter jejuni, a major foodborne pathogenic species causing human gastroenteritis. Although CosR is a response regulator, its cognate sensor kinase has not been identified in C. jejuni. In this study, DNA sequence analysis of the cosR flanking regions revealed that a gene encoding a putative sensor kinase, which we named cosS, is prevalent in non-thermotolerant Campylobacter spp., but not in thermotolerant campylobacters. Phosphorylation assays indicated that C. fetus CosS rapidly autophosphorylates and then phosphorylates C. fetus CosR, suggesting that the CosRS system constitutes a paired two-component signal transduction system in C. fetus. However, C. fetus CosS does not phosphorylate C. jejuni CosR, suggesting that CosR may have different regulatory cascades between thermotolerant and non-thermotolerant Campylobacter species. Comparison of CosR homolog amino acid sequences showed that the conserved phosphorylation residue (D51), which is present in all non-thermotolerant Campylobacter spp., is absent from the CosR homologs of thermotolerant Campylobacter species. However, C. jejuni CosR was not phosphorylated by C. fetus CosS even after site-directed mutagenesis of N51D, implying that C. jejuni CosR may possibly function phosphorylation-independently. In addition, the results of cosS mutational analysis indicated that CosS is not associated with the temperature dependence of the Campylobacter spp. despite its unique divergent distribution only in non-thermotolerant campylobacters. The findings in this study strongly suggest that thermotolerant and non-thermotolerant Campylobacter spp. have different signal sensing mechanisms associated with the CosR regulation.
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Affiliation(s)
- Sunyoung Hwang
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Center for Food and Bioconvergence, Seoul National University, Seoul, Korea
| | - William G. Miller
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Albany, California, United States of America
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Center for Food and Bioconvergence, Seoul National University, Seoul, Korea
- * E-mail: (BJ); (SR)
| | - Byeonghwa Jeon
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- * E-mail: (BJ); (SR)
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Malde A, Gangaiah D, Chandrashekhar K, Pina-Mimbela R, Torrelles JB, Rajashekara G. Functional characterization of exopolyphosphatase/guanosine pentaphosphate phosphohydrolase (PPX/GPPA) of Campylobacter jejuni. Virulence 2014; 5:521-33. [PMID: 24569519 DOI: 10.4161/viru.28311] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The inorganic polyphosphate (poly-P) is a key regulator of stress responses and virulence in many bacterial pathogens including Campylobacter jejuni. The role of exopolyphosphatases/guanosine pentaphosphate (pppGpp) phosphohydrolases (PPX/GPPA) in poly-P homeostasis and C. jejuni pathobiology remains unexplored. Here, we analyzed deletion mutants (∆ppx1, ∆ppx2) and the double knockout mutant (dkppx), all ∆ppx mutants exhibited increased capacity to accumulate poly-P; however only ∆ppx1 and dkppx mutants showed decreased accumulation of ppGpp, an alarmone molecule that regulates stringent response in bacteria, suggesting potential dual role for PPX1/GPPA. Nutrient survival defect of ∆ppx mutants was rescued by the supplementation of specific amino acids implying that survival defect may be associated with decreased ppGpp and/ or increased poly-P in ∆ppx mutants. The ppk1 and spoT were upregulated in both ∆ppx1 and ∆ppx2 suggesting a compensatory role for SpoT and Ppk1 in poly-P and ppGpp homeostasis. The lack of ppx genes resulted in defects in motility, biofilm formation, nutrient stress survival, invasion and intracellular survival indicating that maintaining a certain level of poly-P is critical for ppx genes in C. jejuni pathophysiology. Both ppx1 and ppx2 mutants were resistant to human complement-mediated killing; however, the dkppx mutant was sensitive. The serum susceptibility did not occur in the presence of MgCl 2 and EGTA suggesting an involvement of the classical or lectin pathway of complement mediated killing. Interestingly, the chicken serum did not have any effect on the ∆ppx mutants' survival. The observed serum susceptibility was not related to C. jejuni surface capsule and lipooligosaccharide structures. Our study underscores the importance of PPX/GPPA proteins in poly-P and ppGpp homeostasis, two critical molecules that modulate environmental stress responses and virulence in C. jejuni.
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Affiliation(s)
- Anandkumar Malde
- Food Animal Health Research Program; Department of Veterinary Preventive Medicine; College of Veterinary Medicine; The Ohio State University; Wooster, OH USA
| | - Dharanesh Gangaiah
- Food Animal Health Research Program; Department of Veterinary Preventive Medicine; College of Veterinary Medicine; The Ohio State University; Wooster, OH USA
| | - Kshipra Chandrashekhar
- Food Animal Health Research Program; Department of Veterinary Preventive Medicine; College of Veterinary Medicine; The Ohio State University; Wooster, OH USA
| | - Ruby Pina-Mimbela
- Food Animal Health Research Program; Department of Veterinary Preventive Medicine; College of Veterinary Medicine; The Ohio State University; Wooster, OH USA
| | - Jordi B Torrelles
- Department of Microbial Infection and Immunity; Center for Microbial Interface Biology; The Ohio State University; Columbus, OH USA
| | - Gireesh Rajashekara
- Food Animal Health Research Program; Department of Veterinary Preventive Medicine; College of Veterinary Medicine; The Ohio State University; Wooster, OH USA
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Oh E, Jeon B. Role of alkyl hydroperoxide reductase (AhpC) in the biofilm formation of Campylobacter jejuni. PLoS One 2014; 9:e87312. [PMID: 24498070 PMCID: PMC3909096 DOI: 10.1371/journal.pone.0087312] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 12/20/2013] [Indexed: 11/18/2022] Open
Abstract
Biofilm formation of Campylobacter jejuni, a major cause of human gastroenteritis, contributes to the survival of this pathogenic bacterium in different environmental niches; however, molecular mechanisms for its biofilm formation have not been fully understood yet. In this study, the role of oxidative stress resistance in biofilm formation was investigated using mutants defective in catalase (KatA), superoxide dismutase (SodB), and alkyl hydroperoxide reductase (AhpC). Biofilm formation was substantially increased in an ahpC mutant compared to the wild type, and katA and sodB mutants. In contrast to the augmented biofilm formation of the ahpC mutant, a strain overexpressing ahpC exhibited reduced biofilm formation. A perR mutant and a CosR-overexpression strain, both of which upregulate ahpC, also displayed decreased biofilms. However, the introduction of the ahpC mutation to the perR mutant and the CosR-overexpression strain substantially enhanced biofilm formation. The ahpC mutant accumulated more total reactive oxygen species and lipid hydroperoxides than the wild type, and the treatment of the ahpC mutant with antioxidants reduced biofilm formation to the wild-type level. Confocal microscopy analysis showed more microcolonies were developed in the ahpC mutant than the wild type. These results successfully demonstrate that AhpC plays an important role in the biofilm formation of C. jejuni.
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Affiliation(s)
- Euna Oh
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Byeonghwa Jeon
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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Frirdich E, Vermeulen J, Biboy J, Soares F, Taveirne ME, Johnson JG, DiRita VJ, Girardin SE, Vollmer W, Gaynor EC. Peptidoglycan LD-carboxypeptidase Pgp2 influences Campylobacter jejuni helical cell shape and pathogenic properties and provides the substrate for the DL-carboxypeptidase Pgp1. J Biol Chem 2014; 289:8007-18. [PMID: 24394413 PMCID: PMC3961634 DOI: 10.1074/jbc.m113.491829] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Despite the importance of Campylobacter jejuni as a pathogen, little is known about the fundamental aspects of its peptidoglycan (PG) structure and factors modulating its helical morphology. A PG dl-carboxypeptidase Pgp1 essential for maintenance of C. jejuni helical shape was recently identified. Bioinformatic analysis revealed the CJJ81176_0915 gene product as co-occurring with Pgp1 in several organisms. Deletion of cjj81176_0915 (renamed pgp2) resulted in straight morphology, representing the second C. jejuni gene affecting cell shape. The PG structure of a Δpgp2 mutant showed an increase in tetrapeptide-containing muropeptides and a complete absence of tripeptides, consistent with ld-carboxypeptidase activity, which was confirmed biochemically. PG analysis of a Δpgp1Δpgp2 double mutant demonstrated that Pgp2 activity is required to generate the tripeptide substrate for Pgp1. Loss of pgp2 affected several pathogenic properties; the deletion strain was defective for motility in semisolid agar, biofilm formation, and fluorescence on calcofluor white. Δpgp2 PG also caused decreased stimulation of the human nucleotide-binding oligomerization domain 1 (Nod1) proinflammatory mediator in comparison with wild type, as expected from the reduction in muropeptide tripeptides (the primary Nod1 agonist) in the mutant; however, these changes did not alter the ability of the Δpgp2 mutant strain to survive within human epithelial cells or to elicit secretion of IL-8 from epithelial cells after infection. The pgp2 mutant also showed significantly reduced fitness in a chick colonization model. Collectively, these analyses enhance our understanding of C. jejuni PG maturation and help to clarify how PG structure and cell shape impact pathogenic attributes.
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Affiliation(s)
- Emilisa Frirdich
- From the Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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56
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Molecular methods to investigate adhesion, transmigration, invasion and intracellular survival of the foodborne pathogen Campylobacter jejuni. J Microbiol Methods 2013; 95:8-23. [DOI: 10.1016/j.mimet.2013.06.031] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 06/18/2013] [Accepted: 06/28/2013] [Indexed: 01/08/2023]
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Dufour V, Li J, Flint A, Rosenfeld E, Rivoal K, Georgeault S, Alazzam B, Ermel G, Stintzi A, Bonnaure-Mallet M, Baysse C. Inactivation of the LysR regulator Cj1000 of Campylobacter jejuni affects host colonization and respiration. MICROBIOLOGY-SGM 2013; 159:1165-1178. [PMID: 23558264 DOI: 10.1099/mic.0.062992-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Transcriptional regulation mediates adaptation of pathogens to environmental stimuli and is important for host colonization. The Campylobacter jejuni genome sequence reveals a surprisingly small set of regulators, mostly of unknown function, suggesting an intricate regulatory network. Interestingly, C. jejuni lacks the homologues of ubiquitous regulators involved in stress response found in many other Gram-negative bacteria. Nonetheless, cj1000 is predicted to encode the sole LysR-type regulator in the C. jejuni genome, and thus may be involved in major adaptation pathways. A cj1000 mutant strain was constructed and found to be attenuated in its ability to colonize 1-day-old chicks. Complementation of the cj1000 mutation restored the colonization ability to wild-type levels. The mutant strain was also outcompeted in a competitive colonization assay of the piglet intestine. Oxygraphy was carried out for what is believed to be the first time with the Oroboros Oxygraph-2k on C. jejuni and revealed a role for Cj1000 in controlling O2 consumption. Furthermore, microarray analysis of the cj1000 mutant revealed both direct and indirect regulatory targets, including genes involved in energy metabolism and oxidative stress defences. These results highlight the importance of Cj1000 regulation in host colonization and in major physiological pathways.
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Affiliation(s)
| | - Jennifer Li
- Department of Biochemistry, Immunology and Microbiology, Ottawa Institute of Systems Biology, University of Ottawa, ON, Canada
| | - Annika Flint
- Department of Biochemistry, Immunology and Microbiology, Ottawa Institute of Systems Biology, University of Ottawa, ON, Canada
| | | | | | | | | | | | - Alain Stintzi
- Department of Biochemistry, Immunology and Microbiology, Ottawa Institute of Systems Biology, University of Ottawa, ON, Canada
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58
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Bell JA, Jerome J, Plovanich-Jones AE, Smith EJ, Gettings JR, Kim HY, Landgraf JR, Lefébure T, Kopper JJ, Rathinam VA, St. Charles JL, Buffa BA, Brooks AP, Poe SA, Eaton KA, Stanhope MJ, Mansfield LS. Outcome of infection of C57BL/6 IL-10(-/-) mice with Campylobacter jejuni strains is correlated with genome content of open reading frames up- and down-regulated in vivo. Microb Pathog 2013; 54:1-19. [PMID: 22960579 PMCID: PMC4118490 DOI: 10.1016/j.micpath.2012.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 08/07/2012] [Indexed: 12/12/2022]
Abstract
Human Campylobacter jejuni infection can result in an asymptomatic carrier state, watery or bloody diarrhea, bacteremia, meningitis, or autoimmune neurological sequelae. Infection outcomes of C57BL/6 IL-10(-/-) mice orally infected with twenty-two phylogenetically diverse C. jejuni strains were evaluated to correlate colonization and disease phenotypes with genetic composition of the strains. Variation between strains was observed in colonization, timing of development of clinical signs, and occurrence of enteric lesions. Five pathotypes of C. jejuni in C57BL/6 IL-10(-/-) mice were delineated: little or no colonization, colonization without disease, colonization with enteritis, colonization with hemorrhagic enteritis, and colonization with neurological signs with or without enteritis. Virulence gene content of ten sequenced strains was compared in silico; virulence gene content of twelve additional strains was compared using a C. jejuni pan-genome microarray. Neither total nor virulence gene content predicted pathotype; nor was pathotype correlated with multilocus sequence type. Each strain was unique with regard to absences of known virulence-related loci and/or possession of point mutations and indels, including phase variation, in virulence-related genes. An experiment in C. jejuni 11168-infected germ-free mice showed that expression levels of ninety open reading frames (ORFs) were significantly up- or down-regulated in the mouse cecum at least two-fold compared to in vitro growth. Genomic content of these ninety C. jejuni 11168 ORFs was significantly correlated with the capacity to colonize and cause enteritis in C57BL/6 IL-10(-/-) mice. Differences in gene expression levels and patterns are thus an important determinant of pathotype in C. jejuni strains in this mouse model.
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Affiliation(s)
- J. A. Bell
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - J.P. Jerome
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
- Department of Microbiology and Molecular Genetics, College of Natural Sciences, Michigan State University, East Lansing, MI 48824
| | - A. E. Plovanich-Jones
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - E. J. Smith
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
- Comparative Medicine and Integrative Biology Program, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - J. R. Gettings
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - H. Y. Kim
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - J. R. Landgraf
- Research Technology Support Facility, Michigan State University, East Lansing, MI 48824
| | - T. Lefébure
- Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
| | - J. J. Kopper
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
- Cell and Molecular Biology Program, College of Natural Sciences, Michigan State University, East Lansing, MI 48824
| | - V. A. Rathinam
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
- Comparative Medicine and Integrative Biology Program, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - J. L. St. Charles
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
- Comparative Medicine and Integrative Biology Program, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - B. A. Buffa
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - A. P. Brooks
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - S. A. Poe
- Laboratory Animal Medicine Unit, University of Michigan Medical School, Ann Arbor, MI 48109; Laboratory Animal Medicine Unit, University of Michigan Medical School, Ann Arbor, MI 48109
| | - K. A. Eaton
- Laboratory Animal Medicine Unit, University of Michigan Medical School, Ann Arbor, MI 48109; Laboratory Animal Medicine Unit, University of Michigan Medical School, Ann Arbor, MI 48109
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - M. J. Stanhope
- Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
| | - L. S. Mansfield
- Comparative Enteric Diseases Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
- Comparative Medicine and Integrative Biology Program, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
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Abstract
The diarrheal pathogen Campylobacter jejuni and other gastrointestinal bacteria encounter changes in osmolarity in the environment, through exposure to food processing, and upon entering host organisms, where osmotic adaptation can be associated with virulence. In this study, growth profiles, transcriptomics, and phenotypic, mutant, and single-cell analyses were used to explore the effects of hyperosmotic stress exposure on C. jejuni. Increased growth inhibition correlated with increased osmotic concentration, with both ionic and nonionic stressors inhibiting growth at 0.620 total osmol liter(-1). C. jejuni adaptation to a range of osmotic stressors and concentrations was accompanied by severe filamentation in subpopulations, with microscopy indicating septum formation and phenotypic diversity between individual cells in a filament. Population heterogeneity was also exemplified by the bifurcation of colony morphology into small and large variants on salt stress plates. Flow cytometry of C. jejuni harboring green fluorescent protein (GFP) fused to the ATP synthase promoter likewise revealed bimodal subpopulations under hyperosmotic stress. We also identified frequent hyperosmotic stress-sensitive variants within the clonal wild-type population propagated on standard laboratory medium. Microarray analysis following hyperosmotic upshift revealed enhanced expression of heat shock genes and genes encoding enzymes for synthesis of potential osmoprotectants and cross-protective induction of oxidative stress genes. The capsule export gene kpsM was also upregulated, and an acapsular mutant was defective for growth under hyperosmotic stress. For C. jejuni, an organism lacking most conventional osmotic response factors, these data suggest an unusual hyperosmotic stress response, including likely "bet-hedging" survival strategies relying on the presence of stress-fit individuals in a heterogeneous population.
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FdhTU-modulated formate dehydrogenase expression and electron donor availability enhance recovery of Campylobacter jejuni following host cell infection. J Bacteriol 2012; 194:3803-13. [PMID: 22636777 DOI: 10.1128/jb.06665-11] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Campylobacter jejuni is a food-borne bacterial pathogen that colonizes the intestinal tract and causes severe gastroenteritis. Interaction with host epithelial cells is thought to enhance severity of disease, and the ability of C. jejuni to modulate its metabolism in different in vivo and environmental niches contributes to its success as a pathogen. A C. jejuni operon comprising two genes that we designated fdhT (CJJ81176_1492) and fdhU (CJJ81176_1493) is conserved in many bacterial species. Deletion of fdhT or fdhU in C. jejuni resulted in apparent defects in adherence and/or invasion of Caco-2 epithelial cells when assessed by CFU enumeration on standard Mueller-Hinton agar. However, fluorescence microscopy indicated that each mutant invaded cells at wild-type levels, instead suggesting roles for FdhTU in either intracellular survival or postinvasion recovery. The loss of fdhU caused reduced mRNA levels of formate dehydrogenase (FDH) genes and a severe defect in FDH activity. Cell infection phenotypes of a mutant deleted for the FdhA subunit of FDH and an ΔfdhU ΔfdhA double mutant were similar to those of a ΔfdhU mutant, which likewise suggested that FdhU and FdhA function in the same pathway. Cell infection assays followed by CFU enumeration on plates supplemented with sodium sulfite abolished the ΔfdhU and ΔfdhA mutant defects and resulted in significantly enhanced recovery of all strains, including wild type, at the invasion and intracellular survival time points. Collectively, our data indicate that FdhTU and FDH are required for optimal recovery following cell infection and suggest that C. jejuni alters its metabolic potential in the intracellular environment.
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Frirdich E, Biboy J, Adams C, Lee J, Ellermeier J, Gielda LD, DiRita VJ, Girardin SE, Vollmer W, Gaynor EC. Peptidoglycan-modifying enzyme Pgp1 is required for helical cell shape and pathogenicity traits in Campylobacter jejuni. PLoS Pathog 2012; 8:e1002602. [PMID: 22457624 PMCID: PMC3310789 DOI: 10.1371/journal.ppat.1002602] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 02/08/2012] [Indexed: 11/18/2022] Open
Abstract
The impact of bacterial morphology on virulence and transmission attributes of pathogens is poorly understood. The prevalent enteric pathogen Campylobacter jejuni displays a helical shape postulated as important for colonization and host interactions. However, this had not previously been demonstrated experimentally. C. jejuni is thus a good organism for exploring the role of factors modulating helical morphology on pathogenesis. We identified an uncharacterized gene, designated pgp1 (peptidoglycan peptidase 1), in a calcofluor white-based screen to explore cell envelope properties important for C. jejuni virulence and stress survival. Bioinformatics showed that Pgp1 is conserved primarily in curved and helical bacteria. Deletion of pgp1 resulted in a striking, rod-shaped morphology, making pgp1 the first C. jejuni gene shown to be involved in maintenance of C. jejuni cell shape. Pgp1 contributes to key pathogenic and cell envelope phenotypes. In comparison to wild type, the rod-shaped pgp1 mutant was deficient in chick colonization by over three orders of magnitude and elicited enhanced secretion of the chemokine IL-8 in epithelial cell infections. Both the pgp1 mutant and a pgp1 overexpressing strain – which similarly produced straight or kinked cells – exhibited biofilm and motility defects. Detailed peptidoglycan analyses via HPLC and mass spectrometry, as well as Pgp1 enzyme assays, confirmed Pgp1 as a novel peptidoglycan DL-carboxypeptidase cleaving monomeric tripeptides to dipeptides. Peptidoglycan from the pgp1 mutant activated the host cell receptor Nod1 to a greater extent than did that of wild type. This work provides the first link between a C. jejuni gene and morphology, peptidoglycan biosynthesis, and key host- and transmission-related characteristics. Bacterial cell shape is dictated by the composition of the cell envelope component peptidoglycan. Some important pathogens have a characteristic helical corkscrew morphology that may help them burrow into mucus overlaying cells to initiate colonization and pathogenicity. One example is Campylobacter jejuni, the leading cause of bacterial-induced diarrheal disease in the developed world. Direct evidence supporting the hypothesis that C. jejuni shape is related to its pathogenicity traits has not previously been provided. We identified a gene encoding a peptidase modifying peptidoglycan that is essential for maintaining the C. jejuni corkscrew shape. We can now connect a C. jejuni gene with morphology and peptidoglycan biosynthesis. Loss of this gene was also found to affect pathogenic attributes such as chicken colonization, biofilms, motility, and activation of host inflammatory mediators. In addition, this is the first study to thoroughly characterize C. jejuni peptidoglycan structure and to identify a gene involved in peptidoglycan maintenance. Our findings highlight an emerging theme in bacterial pathogenesis research: the connection between bacterial cell biology and pathogenesis. Finally, our characterization of C. jejuni cell shape and peptidoglycan provides a starting point for further work in this area in C. jejuni and other bacteria with curved and helical morphologies.
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Affiliation(s)
- Emilisa Frirdich
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jacob Biboy
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Calvin Adams
- Wine Research Centre, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jooeun Lee
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Jeremy Ellermeier
- Department of Microbiology and Immunology & Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Lindsay Davis Gielda
- Department of Microbiology and Immunology & Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Victor J. DiRita
- Department of Microbiology and Immunology & Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Stephen E. Girardin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Erin C. Gaynor
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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62
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Ikeda N, Karlyshev AV. Putative mechanisms and biological role of coccoid form formation in Campylobacter jejuni. Eur J Microbiol Immunol (Bp) 2012; 2:41-9. [PMID: 24611120 DOI: 10.1556/eujmi.2.2012.1.7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Accepted: 01/09/2012] [Indexed: 01/09/2023] Open
Abstract
In certain conditions Campylobacter jejuni cells are capable of changing their cell shape from a typically spiral to a coccoid form (CF). By similarity to other bacteria, the latter was initially considered to be a viable but non-culturable form capable of survival in unfavourable conditions. However, subsequent studies with C. jejuni and closely related bacteria Helicobacter pylori suggested that CF represents a non-viable, degenerative form. Until now, the issue on whether the CF of C. jejuni is viable and infective is highly controversial. Despite some preliminary experiments on characterization of CF cells, neither biochemical mechanisms nor genetic determinants involved in C. jejuni cell shape changes have been characterized. In this review, we highlight known molecular mechanisms and genes involved in CF formation in other bacteria. Since orthologous genes are also present in C. jejuni, we suggest that CF formation in these bacteria is also a regulated and genetically determined process. A possible significance of CF in the lifestyle of this important bacterial pathogen is discussed.
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Affiliation(s)
- N Ikeda
- School of Life Sciences, Faculty of Science, Engineering and Computing, Kingston University Penrhyn Road, Kingston-upon Thames, KT1 2EE UK
| | - A V Karlyshev
- School of Life Sciences, Faculty of Science, Engineering and Computing, Kingston University Penrhyn Road, Kingston-upon Thames, KT1 2EE UK
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Szymanski CM, Gaynor E. How a sugary bug gets through the day: recent developments in understanding fundamental processes impacting Campylobacter jejuni pathogenesis. Gut Microbes 2012; 3:135-44. [PMID: 22555465 PMCID: PMC3370946 DOI: 10.4161/gmic.19488] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Campylobacter jejuni is a highly prevalent yet fastidious bacterial pathogen that poses a significant health burden worldwide. Lacking many hallmark virulence factors, it is becoming increasingly clear that C. jejuni pathogenesis involves different strategies compared with other well-characterized enteric organisms. This includes the involvement of basic biological processes and cell envelope glycans in a number of aspects related to pathogenesis. The past few years have seen significant progress in the understanding of these pathways and how they relate to C. jejuni fundamental biology, stress survival, colonization, and virulence attributes. This review focuses on recent studies in three general areas where "pathogenesis" and "basic biology" overlap: physiology, stress responses and glycobiology.
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Affiliation(s)
- Christine M. Szymanski
- Alberta Glycomics Centre and Department of Biological Sciences; University of Alberta; Edmonton, Canada,Correspondence to: Christine M. Szymanski, or Erin Gaynor,
| | - Erin Gaynor
- Department of Microbiology and Immunology; University of British Columbia; Vancouver, Canada,Correspondence to: Christine M. Szymanski, or Erin Gaynor,
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Characterization of Campylobacter jejuni RacRS reveals roles in the heat shock response, motility, and maintenance of cell length homogeneity. J Bacteriol 2012; 194:2342-54. [PMID: 22343300 DOI: 10.1128/jb.06041-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Campylobacter jejuni commensally colonizes the cecum of birds. The RacR (reduced ability to colonize) response regulator was previously shown to be important in avian colonization. To explore the means by which RacR and its cognate sensor kinase RacS may modulate C. jejuni physiology and colonization, ΔracR and ΔracS mutations were constructed in the invasive, virulent strain 81-176, and extensive phenotypic analyses were undertaken. Both the ΔracR and ΔracS mutants exhibited a ~100-fold defect in chick colonization despite no (ΔracS) or minimal (ΔracR) growth defects at 42 °C, the avian body temperature. Each mutant was defective for colony formation at 44°C and in the presence of 0.8% NaCl, both of which are stresses associated with the heat shock response. Promoter-reporter and real-time quantitative PCR (RT-qPCR) analyses revealed that RacR activates racRS and represses dnaJ. Although disregulation of several other heat shock genes was not observed at 38°C, the ΔracR and ΔracS mutants exhibited diminished upregulation of these genes upon a rapid temperature upshift. Furthermore, the ΔracR and ΔracS mutants displayed increased length heterogeneity during exponential growth, with a high proportion of filamented bacteria. Filamented bacteria had reduced swimming speed and were defective for invasion of Caco-2 epithelial cells. Soft-agar studies also revealed that the loss of racR or racS resulted in whole-population motility defects in viscous medium. These findings reveal new roles for RacRS in C. jejuni physiology, each of which is likely important during colonization of the avian host.
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Revez J, Rossi M, Ellström P, de Haan C, Rautelin H, Hänninen ML. Finnish Campylobacter jejuni strains of multilocus sequence type ST-22 complex have two lineages with different characteristics. PLoS One 2011; 6:e26880. [PMID: 22039552 PMCID: PMC3200363 DOI: 10.1371/journal.pone.0026880] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 10/05/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Campylobacter jejuni is the major cause of human bacterial gastroenteritis worldwide, and in a minority of cases, post-infectious complications may occur. ST-22 complex (usually Penner serotype 19) strains have been overrepresented among patients with postinfectious complications of campylobacteriosis. We here present a characterization of a collection of 27 Finnish C. jejuni strains of ST-22 complex, from humans (22 strains) and animal sources (five strains), with the aim of contributing to our knowledge of the pathogenesis of C. jejuni infections. METHODOLOGY/PRINCIPAL FINDINGS All strains were analyzed by pulsed-field gel electrophoresis (PFGE) genotyping, lipo-oligosaccharide (LOS) locus class, Y-glutamyl transpeptidase (GGT) activity, in vitro biofilm formation ability, invasion and adhesion in HeLa cells and induction of IL-8 production. ST-22 complex contained five STs (ST-22; ST-1947; ST-1966; ST-3892; ST-3996) which were homogeneous in having sialylated LOS class A(1) but on the other hand were distinguished into two major lineages according to the major STs (ST-22 and ST-1947) by different PFGE genotypes and certain other characteristics. All ST-22 strains had similar SmaI PFGE profiles, were GGT positive, and formed biofilms, except one strain, while ST-1947 strains were all GGT negative, did not form biofilm, had significantly higher motility than ST-22 (p<0.05) and had their SmaI PFGE profile. Invasion and adhesion as well as induction of IL-8 production on HeLa cells were strain-dependent characteristics. CONCLUSIONS/SIGNIFICANCE ST-22 complex strains, reveal potential for molecular mimicry in host interactions upon infection as they all express sialylated LOS class A(1). The two major STs, ST-22 and ST-1947 formed two homogeneous lineages, which differed from each other both phenotypically and genetically, suggesting that the strains may have evolved separately, perhaps by interacting with different spectra of hosts. Further studies are needed in order to understand if these two lineages are associated with different disease outcomes.
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Affiliation(s)
- Joana Revez
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
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Gundogdu O, Mills DC, Elmi A, Martin MJ, Wren BW, Dorrell N. The Campylobacter jejuni transcriptional regulator Cj1556 plays a role in the oxidative and aerobic stress response and is important for bacterial survival in vivo. J Bacteriol 2011; 193:4238-49. [PMID: 21642451 PMCID: PMC3147681 DOI: 10.1128/jb.05189-11] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 05/25/2011] [Indexed: 01/11/2023] Open
Abstract
Campylobacter jejuni is the leading bacterial cause of human gastroenteritis worldwide. Despite stringent microaerobic growth requirements, C. jejuni is ubiquitous in the aerobic environment and so must possess regulatory systems to sense and adapt to external stimuli, such as oxidative and aerobic (O(2)) stress. Reannotation of the C. jejuni NCTC11168 genome sequence identified Cj1556 (originally annotated as a hypothetical protein) as a MarR family transcriptional regulator, and further analysis indicated a potential role in regulating the oxidative stress response. A C. jejuni 11168H Cj1556 mutant exhibited increased sensitivity to oxidative and aerobic stress, decreased ability for intracellular survival in Caco-2 human intestinal epithelial cells and J774A.1 mouse macrophages, and a reduction in virulence in the Galleria mellonella infection model. Microarray analysis of gene expression changes in the Cj1556 mutant indicated negative autoregulation of Cj1556 expression and downregulation of genes associated with oxidative and aerobic stress responses, such as katA, perR, and hspR. Electrophoretic mobility shift assays confirmed the binding of recombinant Cj1556 to the promoter region upstream of the Cj1556 gene. cprS, which encodes a sensor kinase involved in regulation of biofilm formation, was also upregulated in the Cj1556 mutant, and subsequent studies showed that the mutant had a reduced ability to form biofilms. This study identified a novel C. jejuni transcriptional regulator, Cj1556, that is involved in oxidative and aerobic stress responses and is important for the survival of C. jejuni in the natural environment and in vivo.
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Affiliation(s)
- Ozan Gundogdu
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Dominic C. Mills
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Abdi Elmi
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Melissa J. Martin
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Brendan W. Wren
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Nick Dorrell
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
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The NO-responsive hemoglobins of Campylobacter jejuni: Concerted responses of two globins to NO and evidence in vitro for globin regulation by the transcription factor NssR. Nitric Oxide 2011; 25:234-41. [DOI: 10.1016/j.niox.2010.12.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/23/2010] [Accepted: 12/29/2010] [Indexed: 01/10/2023]
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Hwang S, Kim M, Ryu S, Jeon B. Regulation of oxidative stress response by CosR, an essential response regulator in Campylobacter jejuni. PLoS One 2011; 6:e22300. [PMID: 21811584 PMCID: PMC3139631 DOI: 10.1371/journal.pone.0022300] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 06/18/2011] [Indexed: 11/20/2022] Open
Abstract
CosR (Campylobacter oxidative stress regulator; Cj0355c) is an OmpR-type response regulator essential for the viability of Campylobacter jejuni, a leading foodborne pathogen causing human gastroenteritis worldwide. Despite importance, the function of CosR remains completely unknown mainly because of cell death caused by its knockout mutation. To overcome this technical limitation, in this study, antisense technology was used to investigate the regulatory function of CosR by modulating the level of CosR expression. Two-dimensional gel electrophoresis (2DGE) was performed to identify the CosR regulon either by suppressing CosR expression with antisense peptide nucleic acid (PNA) or by overexpressing CosR in C. jejuni. According to the results of 2DGE, CosR regulated 32 proteins involved in various cellular processes. Notably, CosR negatively regulated a few key proteins of the oxidative stress response of C. jejuni, such as SodB, Dps, Rrc and LuxS, whereas CosR positively controlled AhpC. Electrophoretic mobility shift assay showed that CosR directly bound to the promoter region of the oxidative stress genes. DNase I footprinting assays identified 21-bp CosR binding sequences in the sodB and ahpC promoters, suggesting CosR specifically recognizes and binds to the regulated genes. Interestingly, the level of CosR protein was significantly reduced by paraquat (a superoxide generator) but not by hydrogen peroxide. Consistent with the overall negative regulation of oxidative stress defense proteins by CosR, the CosR knockdown by antisense rendered C. jejuni more resistant to oxidative stress compared to the wild type. Overall, this study reveals the important role played by the essential response regulator CosR in the oxidative stress defense of C. jejuni.
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Affiliation(s)
- Sunyoung Hwang
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Center for Agricultural Biomaterials, Seoul National University, Seoul, Korea
| | - Minkyeong Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Center for Agricultural Biomaterials, Seoul National University, Seoul, Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, and Center for Agricultural Biomaterials, Seoul National University, Seoul, Korea
| | - Byeonghwa Jeon
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada
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Hermans D, Van Deun K, Martel A, Van Immerseel F, Messens W, Heyndrickx M, Haesebrouck F, Pasmans F. Colonization factors of Campylobacter jejuni in the chicken gut. Vet Res 2011; 42:82. [PMID: 21714866 PMCID: PMC3156733 DOI: 10.1186/1297-9716-42-82] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 06/29/2011] [Indexed: 11/10/2022] Open
Abstract
Campylobacter contaminated broiler chicken meat is an important source of foodborne gastroenteritis and poses a serious health burden in industrialized countries. Broiler chickens are commonly regarded as a natural host for this zoonotic pathogen and infected birds carry a very high C. jejuni load in their gastrointestinal tract, especially the ceca. This eventually results in contaminated carcasses during processing. Current intervention methods fail to reduce the colonization of broiler chicks by C. jejuni due to an incomplete understanding on the interaction between C. jejuni and its avian host. Clearly, C. jejuni developed several survival and colonization mechanisms which are responsible for its highly adapted nature to the chicken host. But how these mechanisms interact with one another, leading to persistent, high-level cecal colonization remains largely obscure. A plethora of mutagenesis studies in the past few years resulted in the identification of several of the genes and proteins of C. jejuni involved in different aspects of the cellular response of this bacterium in the chicken gut. In this review, a thorough, up-to-date overview will be given of the survival mechanisms and colonization factors of C. jejuni identified to date. These factors may contribute to our understanding on how C. jejuni survival and colonization in chicks is mediated, as well as provide potential targets for effective subunit vaccine development.
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Affiliation(s)
- David Hermans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Kim Van Deun
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Filip Van Immerseel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Winy Messens
- Institute for Agricultural and Fisheries Research, Technology and Food Unit, Brusselsesteenweg 370, 9090 Melle, Belgium
- Current address: Biological Hazards (BIOHAZ) Unit, European Food Safety Authority (EFSA), Largo N. Palli 5/A, I-43121 Parma, Italy
| | - Marc Heyndrickx
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
- Institute for Agricultural and Fisheries Research, Technology and Food Unit, Brusselsesteenweg 370, 9090 Melle, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Abstract
As an etiological agent of bacterial sepsis and wound infections, Vibrio vulnificus is unique among the Vibrionaceae. The most intensely studied of its virulence factors is the capsular polysaccharide (CPS). Over 100 CPS types have been identified, yet little is known about the genetic mechanisms that drive such diversity. Chitin, the second-most-abundant polysaccharide in nature, is known to induce competence in Vibrio species. Here, we show that the frequency of chitin-induced transformation in V. vulnificus varies by strain and that (GlcNAc)(2) is the shortest chitin-derived polymer capable of inducing competence. Transformation frequencies (TFs) increased 8-fold when mixed-culture biofilms were exposed to a strain-specific lytic phage, suggesting that the lysis of dead cells during lytic infection increased the amount of extracellular DNA within the biofilm that was available for transfer. Furthermore, we show that V. vulnificus can undergo chitin-dependent carbotype conversion following the uptake and recombination of complete cps loci from exogenous genomic DNA (gDNA). The acquisition of a partial locus was also demonstrated when internal regions of homology between the endogenous and exogenous loci existed. This suggested that the same mechanism governing the transfer of complete cps loci also contributed to their evolution by generating novel combinations of CPS biosynthesis genes. Since no evidence that cps loci were preferentially acquired during natural transformation (random transposon-tagged DNA was readily taken up in chitin transformation assays) exists, the phenomenon of chitin-induced transformation likely plays an important but general role in the evolution of this genetically promiscuous genus.
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71
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Campylobacter protein oxidation influences epithelial cell invasion or intracellular survival as well as intestinal tract colonization in chickens. J Appl Genet 2011; 51:383-93. [PMID: 20720313 DOI: 10.1007/bf03208868] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The Dsb family of redox proteins catalyzes disulfide bond formation and isomerization. Since mutations in dsb genes change the conformation and stability of many extracytoplasmic proteins, and since many virulence factors of pathogenic bacteria are extracytoplasmic, inactivation of dsb genes often results in pathogen attenuation. This study investigated the role of 2 membrane-bound oxidoreductases, DsbB and DsbI, in the Campylobacter jejuni oxidative Dsb pathway. Campylobacter mutants, lacking DsbB or DsbI or both, were constructed by allelic replacement and used in the human intestinal epithelial T84 cell line for the gentamicin protection assay (invasion assay) and chicken colonization experiments. In C. coli strain 23/1, the inactivation of the dsbB or dsbI gene separately did not significantly affect the colonization process. However, simultaneous disruption of both membrane-bound oxidoreductase genes significantly decreased the strain’s ability to colonize chicken intestines. Moreover, C. jejuni strain 81-176 with mutated dsbB or dsbI genes showed reduced invasion/intracellular survival abilities. No cells of the double mutants (dsbB⁻ dsbI⁻) of C. jejuni 81-176 were recovered from human cells after 3 h of invasion.
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72
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Di Cagno R, De Angelis M, Calasso M, Gobbetti M. Proteomics of the bacterial cross-talk by quorum sensing. J Proteomics 2011; 74:19-34. [DOI: 10.1016/j.jprot.2010.09.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 09/14/2010] [Accepted: 09/29/2010] [Indexed: 01/03/2023]
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Abstract
Bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. Biofilms protect and allow bacteria to survive and thrive in hostile environments. Bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared with their planktonic counterparts. The ability to form biofilms is now considered a universal attribute of micro-organisms. Diseases associated with biofilms require novel methods for their prevention, diagnosis and treatment; this is largely due to the properties of biofilms. Surprisingly, biofilm formation by bacterial pathogens of veterinary importance has received relatively little attention. Here, we review the current knowledge of bacterial biofilms as well as studies performed on animal pathogens.
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Gangaiah D, Liu Z, Arcos J, Kassem II, Sanad Y, Torrelles JB, Rajashekara G. Polyphosphate kinase 2: a novel determinant of stress responses and pathogenesis in Campylobacter jejuni. PLoS One 2010; 5:e12142. [PMID: 20808906 PMCID: PMC2923150 DOI: 10.1371/journal.pone.0012142] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 07/21/2010] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Inorganic polyphosphate (poly P) plays an important role in stress tolerance and virulence in many bacteria. PPK1 is the principal enzyme involved in poly P synthesis, while PPK2 uses poly P to generate GTP, a signaling molecule that serves as an alternative energy source and a precursor for various physiological processes. Campylobacter jejuni, an important cause of foodborne gastroenteritis in humans, possesses homologs of both ppk1 and ppk2. ppk1 has been previously shown to impact the pathobiology of C. jejuni. METHODOLOGY/PRINCIPAL FINDINGS Here, we demonstrate for the first time that the deletion of ppk2 in C. jejuni resulted in a significant decrease in poly P-dependent GTP synthesis, while displaying an increased intracellular ATP:GTP ratio. The Deltappk2 mutant exhibited a significant survival defect under osmotic, nutrient, aerobic, and antimicrobial stresses and displayed an enhanced ability to form static biofilms. However, the Deltappk2 mutant was not defective in poly P and ppGpp synthesis suggesting that PPK2-mediated stress tolerance is not ppGpp-mediated. Importantly, the Deltappk2 mutant was significantly attenuated in invasion and intracellular survival within human intestinal epithelial cells as well as in chicken colonization. CONCLUSIONS/SIGNIFICANCE Taken together, we have highlighted the role of PPK2 as a novel pathogenicity determinant that is critical for C. jejuni survival, adaptation, and persistence in the host environments. PPK2 is absent in humans and animals; therefore, can serve as a novel target for therapeutic intervention of C. jejuni infections.
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Affiliation(s)
- Dharanesh Gangaiah
- Food Animal Health Research Program, Ohio Agricultural Research Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, United States of America
| | - Zhe Liu
- Food Animal Health Research Program, Ohio Agricultural Research Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, United States of America
| | - Jesús Arcos
- Center for Microbial Interface Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Issmat I. Kassem
- Food Animal Health Research Program, Ohio Agricultural Research Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, United States of America
| | - Yasser Sanad
- Food Animal Health Research Program, Ohio Agricultural Research Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, United States of America
| | - Jordi B. Torrelles
- Center for Microbial Interface Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Gireesh Rajashekara
- Food Animal Health Research Program, Ohio Agricultural Research Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, United States of America
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75
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Haddock G, Mullin M, MacCallum A, Sherry A, Tetley L, Watson E, Dagleish M, Smith DGE, Everest P. Campylobacter jejuni 81-176 forms distinct microcolonies on in vitro-infected human small intestinal tissue prior to biofilm formation. MICROBIOLOGY-SGM 2010; 156:3079-3084. [PMID: 20616103 DOI: 10.1099/mic.0.039867-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Human small and large intestinal tissue was used to study the interaction of Campylobacter jejuni with its target tissue. The strain used for the study was 81-176 (+pVir). Tissue was processed for scanning and transmission electron microscopy, and by immunohistochemistry for light microscopy. Organisms adhered to the apical surface of ileal tissues at all time points in large numbers, in areas where mucus was present and in distinct groups. Microcolony formation was evident at 1-2 h, with bacteria adhering to mucus on the tissue surface and to each other by flagellar interaction. At later time points (3-4 h), biofilm formation on ileal tissue was evident. Flagellar mutants did not form microcolonies or biofilms in tissue. Few organisms were observed in colonic tissue, with organisms present but not as abundant as in the ileal tissue. This study shows that C. jejuni 81-176 can form microcolonies and biofilms on human intestinal tissue and that this may be an essential step in its ability to cause diarrhoea in man.
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Affiliation(s)
- Graham Haddock
- Department of Paediatric Surgery, Royal Hospital for Sick Children, Glasgow, UK
| | - Margaret Mullin
- Institute of Biological and Life Sciences, University of Glasgow, Glasgow, UK
| | - Amanda MacCallum
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow, UK
| | - Aileen Sherry
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow, UK
| | - Laurence Tetley
- Institute of Biological and Life Sciences, University of Glasgow, Glasgow, UK
| | | | - Mark Dagleish
- Moredun Research Institute, Penicuik, Midlothian, UK
| | - David G E Smith
- Moredun Research Institute, Penicuik, Midlothian, UK.,Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow, UK
| | - Paul Everest
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow, UK
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Haddad N, Marce C, Magras C, Cappelier JM. An overview of methods used to clarify pathogenesis mechanisms of Campylobacter jejuni. J Food Prot 2010; 73:786-802. [PMID: 20377972 DOI: 10.4315/0362-028x-73.4.786] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Thermotolerant campylobacters are the most frequent cause of bacterial infection of the lower intestine worldwide. The mechanism of pathogenesis of Campylobacter jejuni comprises four main stages: adhesion to intestinal cells, colonization of the digestive tract, invasion of targeted cells, and toxin production. In response to the high number of cases of human campylobacteriosis, various virulence study models are available according to the virulence stage being analyzed. The aim of this review is to compare the different study models used to look at human disease. Molecular biology tools used to identify genes or proteins involved in virulence mechanisms are also summarized. Despite high cost and limited availability, animal models are frequently used to study digestive disease, in particular to analyze the colonization stage. Eukaryotic cell cultures have been developed because of fewer restrictions on their use and the lower cost of these cultures compared with animal models, and this ex vivo approach makes it possible to mimic the bacterial cell-host interactions observed in natural disease cases. Models are complemented by molecular biology tools, especially mutagenesis and DNA microarray methods to identify putative virulence genes or proteins and permit their characterization. No current model seems to be ideal for studying the complete range of C. jejuni virulence. However, the models available deal with different aspects of the complex pathogenic mechanisms particular to this bacterium.
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Affiliation(s)
- N Haddad
- Unit INRA 1014 SECALIM, National Veterinary School of Nantes, Route de Gachet, Nantes cedex 3, France
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77
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Biofilm formation by Campylobacter jejuni is increased under aerobic conditions. Appl Environ Microbiol 2010; 76:2122-8. [PMID: 20139307 DOI: 10.1128/aem.01878-09] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The microaerophilic human pathogen Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in the developed world. During transmission through the food chain and the environment, the organism must survive stressful environmental conditions, particularly high oxygen levels. Biofilm formation has been suggested to play a role in the environmental survival of this organism. In this work we show that C. jejuni NCTC 11168 biofilms developed more rapidly under environmental and food-chain-relevant aerobic conditions (20% O(2)) than under microaerobic conditions (5% O(2), 10% CO(2)), although final levels of biofilms were comparable after 3 days. Staining of biofilms with Congo red gave results similar to those obtained with the commonly used crystal violet staining. The level of biofilm formation by nonmotile aflagellate strains was lower than that observed for the motile flagellated strain but nonetheless increased under aerobic conditions, suggesting the presence of flagellum-dependent and flagellum-independent mechanisms of biofilm formation in C. jejuni. Moreover, preformed biofilms shed high numbers of viable C. jejuni cells into the culture supernatant independently of the oxygen concentration, suggesting a continuous passive release of cells into the medium rather than a condition-specific active mechanism of dispersal. We conclude that under aerobic or stressful conditions, C. jejuni adapts to a biofilm lifestyle, allowing survival under detrimental conditions, and that such a biofilm can function as a reservoir of viable planktonic cells. The increased level of biofilm formation under aerobic conditions is likely to be an adaptation contributing to the zoonotic lifestyle of C. jejuni.
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Effects of sequential Campylobacter jejuni 81-176 lipooligosaccharide core truncations on biofilm formation, stress survival, and pathogenesis. J Bacteriol 2010; 192:2182-92. [PMID: 20139192 DOI: 10.1128/jb.01222-09] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Campylobacter jejuni is a highly prevalent human pathogen for which pathogenic and stress survival strategies remain relatively poorly understood. We previously found that a C. jejuni strain 81-176 mutant defective for key virulence and stress survival attributes was also hyper-biofilm and hyperreactive to the UV fluorescent dye calcofluor white (CFW). We hypothesized that screening for CFW hyperreactive mutants would identify additional genes required for C. jejuni pathogenesis properties. Surprisingly, two such mutants harbored lesions in lipooligosaccharide (LOS) genes (waaF and lgtF), indicating a complete loss of the LOS outer core region. We utilized this as an opportunity to explore the role of each LOS core-specific moiety in the pathogenesis and stress survival of this strain and thus also constructed DeltagalT and DeltacstII mutants with more minor LOS truncations. Interestingly, we found that mutants lacking the LOS outer core (DeltawaaF and DeltalgtF but not DeltagalT or DeltacstII mutants) exhibited enhanced biofilm formation. The presence of the complete outer core was also necessary for resistance to complement-mediated killing. In contrast, any LOS truncation, even that of the terminal sialic acid (DeltacstII), resulted in diminished resistance to polymyxin B. The cathelicidin LL-37 was found to be active against C. jejuni, with the LOS mutants exhibiting modest but tiled alterations in LL-37 sensitivity. The DeltawaaF mutant but not the other LOS mutant strains also exhibited a defect in intraepithelial cell survival, an aspect of C. jejuni pathogenesis that has only recently begun to be clarified. Finally, using a mouse competition model, we now provide the first direct evidence for the importance of the C. jejuni LOS in host colonization. Collectively, this study has uncovered novel roles for the C. jejuni LOS, highlights the dynamic nature of the C. jejuni cell envelope, and provides insight into the contribution of specific LOS core moieties to stress survival and pathogenesis.
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79
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van Putten JPM, van Alphen LB, Wösten MMSM, de Zoete MR. Molecular mechanisms of campylobacter infection. Curr Top Microbiol Immunol 2010; 337:197-229. [PMID: 19812984 DOI: 10.1007/978-3-642-01846-6_7] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Campylobacter jejuni is the principal bacterial foodborne pathogen. A major challenge still is to identify the virulence strategies exploited by C. jejuni. Recent genomics, proteomics, and metabolomics approaches indicate that C. jejuni displays extensive inter- and intrastrain variation. The diverse behavior enables bacterial adaptation to different environmental conditions and directs interactions with the gut mucosa. Here, we report recent progress in understanding the molecular mechanisms and functional consequences of the phenotype diversity. The results suggest that C. jejuni actively penetrates the intestinal mucus layer, secretes proteins mainly via its flagellar apparatus, is engulfed by intestinal cells, and can disrupt the integrity of the epithelial lining. C. jejuni stimulates the proinflammatory pathway and the production of a large repertoire of cytokines, chemokines, and innate effector molecules. Novel experimental infection models suggest that the activation of the innate immune response is important for the development of intestinal pathology.
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Affiliation(s)
- Jos P M van Putten
- Department of Infectious Diseases & Immunology, Utrecht University, Yalelaan 1, Utrecht, The Netherlands.
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80
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Windle HJ, Brown PA, Kelleher DP. Proteomics of bacterial pathogenicity: therapeutic implications. Proteomics Clin Appl 2010; 4:215-27. [PMID: 21137045 DOI: 10.1002/prca.200900145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 10/13/2009] [Accepted: 10/19/2009] [Indexed: 01/04/2023]
Abstract
Identification of the molecular mechanisms of host-pathogen interaction is becoming a key focus of proteomics. Analysis of these interactions holds promise for significant developments in the identification of new therapeutic strategies to combat infectious diseases, a process that will also benefit parallel improvements in molecular diagnostics, biomarker identification and drug discovery. This review highlights recent advances in functional proteomics initiatives in infectious disease with emphasis on studies undertaken within physiologically relevant parameters that enable identification of the infectious proteome rather than that of the vegetative state. Deciphering the molecular details of what constitutes physiologically relevant host-pathogen interactions remains an underdeveloped aspect of research into infectious disease. The magnitude of this deficit will be largely influenced by the ease with which model systems can be established to investigate such interactions. As the selective pressures exerted by the host on an infecting pathogen are numerous, the adequacy of certain model systems should be considered carefully.
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Affiliation(s)
- Henry J Windle
- Institute of Molecular Medicine, Trinity College, University of Dublin, Dublin, Ireland.
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81
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Gaskin DJH, van Vliet AHM. Random mutagenesis strategies for Campylobacter and Helicobacter species. Methods Mol Biol 2010; 634:37-52. [PMID: 20676974 DOI: 10.1007/978-1-60761-652-8_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Campylobacter and Helicobacter species are important pathogens in man and animals. The study of their virulence and physiology has been difficult due to the lack of tractable genetic tools, since many of the techniques established in Escherichia coli and related species were found to be non-functional in Campylobacter and Helicobacter species. The advent of functional genomics techniques in the last decade has been accompanied by the development of genetic tools, which take advantage of specific features of Campylobacter and Helicobacter, like natural transformation. This has allowed for the construction of random mutant libraries based on in vitro transposition or ligated loops followed by natural transformation and recombination, thus circumventing selection against sequences when cloning or passaging libraries through E. coli. Uses of the techniques have been in the study of motility, gene expression, and gene essentiality. In this chapter, we discuss the approaches and techniques used for the construction of random mutant libraries in both Campylobacter and Helicobacter.
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82
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Atack JM, Kelly DJ. Oxidative stress in Campylobacter jejuni: responses, resistance and regulation. Future Microbiol 2009; 4:677-90. [PMID: 19659424 DOI: 10.2217/fmb.09.44] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Campylobacter jejuni is a major food-borne human pathogen that paradoxically is an oxygen-sensitive microaerophile, yet must resist the oxidative stresses encountered both in the host and in the environment. Recent studies suggest that, perhaps surprisingly, C. jejuni contains a wide range of enzymes involved in oxidative stress defense, and this review focuses on the properties and roles of these proteins. Although the mechanisms of gene regulation are still poorly understood in C. jejuni, several regulators of the oxidative stress response have been identified and their properties are discussed here. We suggest that future studies should be directed towards identifying the role of additional and less well characterized components involved in oxidative stress resistance, as well as providing a more complete picture of the underlying sensing and regulatory mechanisms.
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Affiliation(s)
- John M Atack
- Centre for Chemical Biology, Department of Chemistry, Krebs Institute, The University of Sheffield, Sheffield, S3 7HF, UK
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83
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Rathbun KM, Thompson SA. Mutation of PEB4 alters the outer membrane protein profile of Campylobacter jejuni. FEMS Microbiol Lett 2009; 300:188-94. [PMID: 19824902 DOI: 10.1111/j.1574-6968.2009.01795.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Campylobacter jejuni is a significant cause of human gastroenteritis worldwide. In an attempt to further define bacterial factors that influence infectivity, Cj0596 was identified as playing a role in C. jejuni virulence. Cj0596 is a periplasmic chaperone that is similar to proteins involved in outer membrane protein (OMP) folding in other bacteria. Mutation of cj0596 caused an alteration in the levels of eight OMPs, compared with wild-type bacteria. Replacement of the cj0596 mutation with the wild-type cj0596 gene restored a wild-type OMP profile. The altered OMP profile in the cj0596 mutant was accompanied by significant changes in several virulence properties, including an increase in the ability to autoagglutinate, increased susceptibility to several antimicrobial agents, and increased biofilm formation. In summary, mutation of cj0596 alters the C. jejuni OMP profile and leads to changes in OMP-related phenotypes involved in C. jejuni pathogenesis.
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Affiliation(s)
- Kimberly M Rathbun
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, 1459 Laney-Walker Blvd., Augusta, GA 30912, USA
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84
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Atypical roles for Campylobacter jejuni amino acid ATP binding cassette transporter components PaqP and PaqQ in bacterial stress tolerance and pathogen-host cell dynamics. Infect Immun 2009; 77:4912-24. [PMID: 19703978 DOI: 10.1128/iai.00571-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Campylobacter jejuni is a human pathogen causing severe diarrheal disease; however, our understanding of the survival of C. jejuni during disease and transmission remains limited. Amino acid ATP binding cassette (AA-ABC) transporters in C. jejuni have been proposed as important pathogenesis factors. We have investigated a novel AA-ABC transporter system, encoded by cj0467 to cj0469, by generating targeted deletions of cj0467 (the membrane transport component) and cj0469 (the ATPase component) in C. jejuni 81-176. The analyses described here have led us to designate these genes paqP and paqQ, respectively (pathogenesis-associated glutamine [q] ABC transporter permease [P] and ATPase [Q]). We found that loss of either component resulted in amino acid uptake defects, most notably diminished glutamine uptake. Altered resistance to a series of environmental and in vivo stresses was also observed: both mutants were hyperresistant to aerobic and organic peroxide stress, and while the DeltapaqP mutant was also hyperresistant to heat and osmotic shock, the DeltapaqQ mutant was more susceptible than the wild type to the latter two stresses. The DeltapaqP and DeltapaqQ mutants also displayed a surprising but statistically significant increase in recovery from macrophages and epithelial cells in short-term intracellular survival assays. Annexin V, 4',6-diamidino-2-phenylindole (DAPI), and Western blot analyses revealed that macrophages infected with the DeltapaqP or DeltapaqQ mutant exhibited transient but significant decreases in cell death and extracellular signal-regulated kinase-mitogen-activated protein kinase activation compared to levels in wild-type-infected cells. The DeltapaqP mutant was not defective in either short-term or longer-term mouse colonization, consistent with its increased stress survival and diminished host cell damage phenotypes. Collectively, these results demonstrate a unique correlation of an AA-ABC transporter with bacterial stress tolerances and host cell responses to pathogen infection.
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85
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Jagusztyn-Krynicka EK, Łaniewski P, Wyszyńska A. Update on Campylobacter jejuni vaccine development for preventing human campylobacteriosis. Expert Rev Vaccines 2009; 8:625-45. [PMID: 19397419 DOI: 10.1586/erv.09.21] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Campylobacteriosis constitutes a serious medical and socioeconomic problem worldwide. Rapidly increasing antibiotic resistance of bacterial strains compels us to develop alternative therapeutic strategies and to search for efficient immunoprophylactic methods. The vast majority of Campylobacter infections in developed countries occur as sporadic cases, mainly caused by eating undercooked Campylobacter-contaminated poultry. The most efficient strategy of decreasing the number of human Campylobacter infections is by implementing protective vaccinations for humans and/or chickens. Despite more than 10 years of research, an effective anti-Campylobacter vaccine has not been developed. This review highlights our increasing knowledge of Campylobacter interaction with host cells and focuses on recently published data describing the efficacy of anti-Campylobacter vaccine prototypes.
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