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Kaur M, Mingeot-Leclercq MP. Maintenance of bacterial outer membrane lipid asymmetry: insight into MlaA. BMC Microbiol 2024; 24:186. [PMID: 38802775 PMCID: PMC11131202 DOI: 10.1186/s12866-023-03138-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 11/29/2023] [Indexed: 05/29/2024] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria acts as an effective barrier to protect against toxic compounds. By nature, the OM is asymmetric with the highly packed lipopolysaccharide (LPS) at the outer leaflet and glycerophospholipids at the inner leaflet. OM asymmetry is maintained by the Mla system, in which is responsible for the retrograde transport of glycerophospholipids from the OM to the inner membrane. This system is comprised of six Mla proteins, including MlaA, an OM lipoprotein involved in the removal of glycerophospholipids that are mis-localized at the outer leaflet of the OM. Interestingly, MlaA was initially identified - and called VacJ - based on its role in the intracellular spreading of Shigella flexneri.Many open questions remain with respect to the Mla system and the mechanism involved in the translocation of mislocated glycerophospholipids at the outer leaflet of the OM, by MlaA. After summarizing the current knowledge on MlaA, we focus on the impact of mlaA deletion on OM lipid composition and biophysical properties of the OM. How changes in OM lipid composition and biophysical properties can impact the generation of membrane vesicles and membrane permeability is discussed. Finally, we explore whether and how MlaA might be a candidate for improving the activity of antibiotics and as a vaccine candidate.Efforts dedicated to understanding the relationship between the OM lipid composition and the mechanical strength of the bacterial envelope and, in turn, how such properties act against external stress, are needed for the design of new targets or drugs for Gram-negative infections.
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Affiliation(s)
- M Kaur
- Louvain Drug Research Institute, Université catholique de Louvain, Unité de Pharmacologie cellulaire et moléculaire, B1.73.05; 73 Av E. Mounier, Brussels, 1200, Belgium
| | - M-P Mingeot-Leclercq
- Louvain Drug Research Institute, Université catholique de Louvain, Unité de Pharmacologie cellulaire et moléculaire, B1.73.05; 73 Av E. Mounier, Brussels, 1200, Belgium.
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2
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Zhang Z, Yan Y, Pang J, Dai L, Zhang Q, Yu EW. Structural basis of DNA recognition of the Campylobacter jejuni CosR regulator. mBio 2024; 15:e0343023. [PMID: 38323832 PMCID: PMC10936212 DOI: 10.1128/mbio.03430-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/09/2024] [Indexed: 02/08/2024] Open
Abstract
Campylobacter jejuni is a foodborne pathogen commonly found in the intestinal tracts of animals. This pathogen is a leading cause of gastroenteritis in humans. Besides its highly infectious nature, C. jejuni is increasingly resistant to a number of clinically administrated antibiotics. As a consequence, the Centers for Disease Control and Prevention has designated antibiotic-resistant Campylobacter as a serious antibiotic resistance threat in the United States. The C. jejuni CosR regulator is essential to the viability of this bacterium and is responsible for regulating the expression of a number of oxidative stress defense enzymes. Importantly, it also modulates the expression of the CmeABC multidrug efflux system, the most predominant and clinically important system in C. jejuni that mediates resistance to multiple antimicrobials. Here, we report structures of apo-CosR and CosR bound with a 21 bp DNA sequence located at the cmeABC promotor region using both single-particle cryo-electron microscopy and X-ray crystallography. These structures allow us to propose a novel mechanism for CosR regulation that involves a long-distance conformational coupling and rearrangement of the secondary structural elements of the regulator to bind target DNA. IMPORTANCE Campylobacter jejuni has emerged as an antibiotic-resistant threat worldwide. CosR is an essential regulator for this bacterium and is important for Campylobacter adaptation to various stresses. Here, we describe the structural basis of CosR binding to target DNA as determined by cryo-electron microscopy and X-ray crystallography. Since CosR is a potential target for intervention, our studies may facilitate the development of novel therapeutics to combat C. jejuni infection.
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Affiliation(s)
- Zhemin Zhang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Yuqi Yan
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Jinji Pang
- Department of Veterinary Microbiology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Lei Dai
- Department of Veterinary Microbiology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Qijing Zhang
- Department of Veterinary Microbiology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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3
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Kanaan MHG. Effect of biofilm formation in a hostile oxidative stress environment on the survival of Campylobacter jejuni recovered from poultry in Iraqi markets. Vet World 2024; 17:136-142. [PMID: 38406363 PMCID: PMC10884572 DOI: 10.14202/vetworld.2024.136-142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 12/14/2023] [Indexed: 02/27/2024] Open
Abstract
Background and Aim Campylobacter jejuni is a major contributor to bacterial enteritis, a common health problem. The resistance of this microaerophilic bacterium to oxidative stress allows it to thrive under aerobic conditions. This study aimed to investigate whether the capacity of C. jejuni to form biofilms in the presence of oxidative stress contributes to the pathogen's ability to thrive in agricultural settings as well as in chicken slaughter lines. Materials and Methods Twenty identified strains originating from chicken samples (eight from caeca contents and 12 from frozen chicken carcasses) were previously isolated and identified according to standard bacteriological protocols, followed by confirmation at the species level using multiplex polymerase chain reaction assay. Crystal violet staining was used to evaluate biofilm formation by these bacteria. Two exposure periods to gaseous ozone (1 and 2 min) were used to assess resistance to oxidative damage. Results Most of the strong biofilm-forming Campylobacter strains came from imported frozen chicken meat (25%), whereas only 10% came from caeca content. After exposure to gaseous ozone at 600 mg/h for 2 min, strong biofilm-producing strains exhibited a higher survival rate with a limited reduction of up to 3 logs, whereas negative biofilm-producing strains exhibited a limited survival rate with a reduction of 6 logs. Conclusion Based on our findings, we hypothesized that the presence of C. jejuni strains capable of forming biofilms in poultry farms and/or chicken production facilities triggers a public health alarm as this bacterium seems to be able to adapt more easily to live and thrive in hostile environmental conditions.
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Affiliation(s)
- Manal H. G. Kanaan
- Department of Nursing, Technical Institute of Suwaria, Middle Technical University, Baghdad, Iraq
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4
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Santos LS, Rossi DA, Braz RF, Fonseca BB, Guidotti–Takeuchi M, Alves RN, Beletti ME, Almeida-Souza HO, Maia LP, Santos PDS, de Souza JB, de Melo RT. Roles of viable but non-culturable state in the survival of Campylobacter jejuni. Front Cell Infect Microbiol 2023; 13:1122450. [PMID: 37056707 PMCID: PMC10086134 DOI: 10.3389/fcimb.2023.1122450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/09/2023] [Indexed: 03/30/2023] Open
Abstract
Despite being considered fragile and fastidious, Campylobacter jejuni is the most prevalent cause of foodborne bacterial gastroenteritis, and chicken meat is considered the main vehicle of transmission to humans. This agent can survive adverse conditions in the form of biofilms, but extreme stress (nutritional, oxidative and thermal) promotes the acquisition of a state called viable but not culturable (VBNC). The emergence of this pathogen worldwide and the recent international requirements in its control instigated us to qualitatively and quantitatively estimate the time required for the acquisition of the VBNC form in 27 strains of C. jejuni, characterize morphological aspects, determine its adaptive and invasive potential and perform comparative metabolomic evaluation. Extreme stress promoted the complete acquisition of the VBNC form in a mean time of 26 days. Starting from an average initial count of 7.8 log CFU/mL, the first four days determined the greatest average reduction of the culturable form of 3.2 log CFU/mL. The scanning and transmission image analyses showed a transition from the typical viable form (VT) to the VBNC form, with initial acquisition of the straight rod shape, followed by loss of the flagella and subdivision into two to 11 imperfect cocci arranged in a chain and rich in cellular content, until their individual release. RT-PCR identified the presence of ciaB and p19 transcripts in the 27 cultivable C. jejuni strains, a character maintained in the VBNC form only for p19 and in 59.3% (16/27) of the VBNC strains for the ciaB gene. The average inoculation of 1.8 log CFU/mL of C. jejuni VBNC into primary chicken embryo hepatocyte cells promoted the occurrence of apoptosis processes significantly after 24 hours of contact by one of the strains tested. In C. jejuni VBNC, we detected higher expression of metabolites linked to protective and adaptation mechanisms and of volatile organic precursor compounds indicative of metabolism interruption. The oscillations in the time of acquisition of the VBNC form together with the presence of transcripts for ciaB and p19, the identification of cell lysis and metabolites that ensure the maintenance of the pathogen alert to the fact that C. jejuni VBNC remains virulent and adapted to stress, which makes evident the potential danger of this latent form, which is not detectable by official methodologies.
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Affiliation(s)
- Leticia Silva Santos
- Laboratory of Molecular Epidemiology, Federal University of Uberlandia, Uberlandia, Brazil
| | - Daise Aparecida Rossi
- Laboratory of Molecular Epidemiology, Federal University of Uberlandia, Uberlandia, Brazil
| | | | | | | | | | | | | | - Larissa Prado Maia
- Biotechnology Institute, Federal University of Uberlandia, Uberlandia, Brazil
| | | | | | - Roberta Torres de Melo
- Laboratory of Molecular Epidemiology, Federal University of Uberlandia, Uberlandia, Brazil
- *Correspondence: Roberta Torres de Melo,
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5
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Nennig M, Clément A, Longueval E, Bernardi T, Ragimbeau C, Tresse O. Metaphenotypes associated with recurrent genomic lineages of Campylobacter jejuni responsible for human infections in Luxembourg. Front Microbiol 2022; 13:901192. [PMID: 36160185 PMCID: PMC9490421 DOI: 10.3389/fmicb.2022.901192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Campylobacter jejuni is a leading cause of foodborne illnesses worldwide. Although considered fragile, this microaerophilic bacterium is able to survive in various challenging environments, which subsequently constitutes multiple sources of transmission for human infection. To test the assumption of acquiring specific features for adaptation and survival, we established a workflow of phenotypic tests related to the survival and the persistence of recurrent and sporadic strains. A representative collection of 83 strains isolated over 13 years from human, mammal, poultry, and environmental sources in Luxembourg, representing different spreading patterns (endemic, epidemic, and sporadic), was screened for survival to oxidative stresses, for acclimating to aerobic conditions (AC), and for persistence on abiotic surfaces. Using the cgMLST Oxford typing scheme for WGS data, the collection was classified into genomic lineages corresponding to host-generalist strains (lineages A and D, CC ST-21), host-specific strains (lineage B, CC ST-257 and lineage C, CC ST-464) and sporadic strains. We established that when a strain survives concentrations beyond 0.25 mM superoxide stress, it is six times more likely to survive hyperoxide stress and that a highly adherent strain is 14 times more likely to develop a biofilm. Surprisingly, more than half of the strains could acclimate to AC but this capacity does not explain the difference between recurrent genomic lineages and sporadic strains and the survival to oxidative stresses, while recurrent strains have a significantly higher adhesion/biofilm formation capacity than sporadic ones. From this work, the genomic lineages with more stable genomes could be characterized by a specific combination of phenotypes, called metaphenotypes. From the functional genomic analyses, the presence of a potentially functional T6SS in the strains of lineage D might explain the propensity of these strains to be strong biofilm producers. Our findings support the hypothesis that phenotypical abilities contribute to the spatio-temporal adaptation and survival of stable genomic lineages. It suggests a selection of better-adapted and persistent strains in challenging stress environments, which could explain the prevalence of these lineages in human infections.
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Affiliation(s)
- Morgane Nennig
- Epidemiology and Microbial Genomics, Laboratoire National de Santé, Dudelange, Luxembourg
- UMR-1280 PhAN, INRAE, Nantes, France
| | - Arnaud Clément
- BioFilm Control, Biopôle Clermont-Limagne, Saint-Beauzire, France
| | - Emmanuelle Longueval
- Epidemiology and Microbial Genomics, Laboratoire National de Santé, Dudelange, Luxembourg
| | - Thierry Bernardi
- BioFilm Control, Biopôle Clermont-Limagne, Saint-Beauzire, France
| | - Catherine Ragimbeau
- Epidemiology and Microbial Genomics, Laboratoire National de Santé, Dudelange, Luxembourg
- *Correspondence: Catherine Ragimbeau,
| | - Odile Tresse
- UMR-1280 PhAN, INRAE, Nantes, France
- Odile Tresse,
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6
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Insights into the Virulence of Campylobacter jejuni Associated with Two-Component Signal Transduction Systems and Single Regulators. MICROBIOLOGY RESEARCH 2022. [DOI: 10.3390/microbiolres13020016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Campylobacter jejuni is one of the major aetiologies of diarrhoea. Understanding the processes and virulence factors contributing to C. jejuni fitness is a cornerstone for developing mitigation strategies. Two-component signal transduction systems, known as two-component systems (TCSs), along with single regulators with no obvious cognate histidine kinase, help pathogens in interacting with their environments, but the available literature on C. jejuni is limited. A typical TCS possesses histidine kinase and response regulator proteins. The objective of this review was to provide insights into the virulence of C. jejuni associated with TCSs and single regulators. Despite limited research, TCSs are important contributors to the pathogenicity of C. jejuni by influencing motility (FlgSR), colonisation (DccRS), nutrient acquisition (PhosSR and BumSR), and stress response (RacRS). Of the single regulators, CbrR and CosR are involved in bile resistance and oxidative stress response, respectively. Cross-talks among TCSs complicate the full elucidation of their molecular mechanisms. Although progress has been made in characterising C. jejuni TCSs, shortfalls such as triggering signals, inability to induce mutations in some genes, or developing suitable in vivo models are still being encountered. Further research is expected to shed light on the unexplored sides of the C. jejuni TCSs, which may allow new drug discoveries and better control strategies.
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Lynch CT, Buttimer C, Epping L, O'Connor J, Walsh N, McCarthy C, O'Brien D, Vaughan C, Semmler T, Bolton D, Coffey A, Lucey B. Phenotypic and genetic analyses of two Campylobacter fetus isolates from a patient with relapsed prosthetic valve endocarditis. Pathog Dis 2021; 79:6486444. [PMID: 34962980 DOI: 10.1093/femspd/ftab055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/24/2021] [Indexed: 11/12/2022] Open
Abstract
Campylobacter fetus can cause intestinal and systemic disease in humans and are well established veterinary and economic pathogens. We report the complete genomic sequences of two C. fetus subsp. fetus (Cff) isolates recovered in 2017 (CITCf01) and 2018 (CITCf02) from a case of recurrent prosthetic valve endocarditis. Both were capable of growth aerobically. Their genomes were found to be highly conserved and syntenic with 99.97% average nucleotide identity (ANI) while differences in their respective sap loci defined the temporal separation of their genomes. Based on core genome phylogeny and ANI of 83 Cff genomes belonging to the previously described human-associated Cff lineage, CITCf01 and CITCf02 grouped in a clade of eleven sequence type (ST)3 Cff (including the Cff type strain NCTC 10842T). CITCf01 and CITCf02 were marked for their lack of unique genomic features when compared to isolates within the subspecies and the type strain in particular. We identified point mutations in oxidative stress response genes, among others, that may contribute to aerobiosis. We report a case of Cff causing relapsed prosthetic valve endocarditis and we highlight the sap island as a polymorphic site within the genetically stable ST3 lineage, central to pathogenicity.
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Affiliation(s)
- Caoimhe T Lynch
- Department of Biological Sciences, Munster Technological University, Rossa Ave, Bishopstown, Cork, Ireland
| | - Colin Buttimer
- APC Microbiome Ireland, University College Cork, College Road, Cork, Ireland
| | - Lennard Epping
- Genome Sequencing and Genomic Epidemiology, Robert Koch Institute, Nordufer 20, Berlin, Germany
| | - James O'Connor
- Department of Microbiology, Grenville Place, Mercy University Hospital, Cork, Ireland
| | - Niamh Walsh
- Department of Biological Sciences, Munster Technological University, Rossa Ave, Bishopstown, Cork, Ireland
| | - Conor McCarthy
- Department of Biological Sciences, Munster Technological University, Rossa Ave, Bishopstown, Cork, Ireland
| | - Deirdre O'Brien
- Department of Microbiology, Grenville Place, Mercy University Hospital, Cork, Ireland
| | - Carl Vaughan
- Department of Cardiology, Grenville Place, Mercy University Hospital, Cork, Ireland
| | - Torsten Semmler
- Genome Sequencing and Genomic Epidemiology, Robert Koch Institute, Nordufer 20, Berlin, Germany
| | - Declan Bolton
- Food Safety Department, Teagasc Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland
| | - Aidan Coffey
- Department of Biological Sciences, Munster Technological University, Rossa Ave, Bishopstown, Cork, Ireland.,APC Microbiome Ireland, University College Cork, College Road, Cork, Ireland
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Rossa Ave, Bishopstown, Cork, Ireland
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8
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Park M, Hwang S, Ryu S, Jeon B. CosR Regulation of perR Transcription for the Control of Oxidative Stress Defense in Campylobacter jejuni. Microorganisms 2021; 9:microorganisms9061281. [PMID: 34208393 PMCID: PMC8231278 DOI: 10.3390/microorganisms9061281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 12/17/2022] Open
Abstract
Oxidative stress resistance is an important mechanism to sustain the viability of oxygen-sensitive microaerophilic Campylobacter jejuni. In C. jejuni, gene expression associated with oxidative stress defense is modulated by PerR (peroxide response regulator) and CosR (Campylobacter oxidative stress regulator). Iron also plays an important role in the regulation of oxidative stress, as high iron concentrations reduce the transcription of perR. However, little is known about how iron affects the transcription of cosR. The level of cosR transcription was increased when the defined media MEMα (Minimum Essential Medium) was supplemented with ferrous (Fe2+) and ferric (Fe3+) iron and the Mueller-Hinton (MH) media was treated with an iron chelator, indicating that iron upregulates cosR transcription. However, other divalent cationic ions, such as Zn2+, Cu2+, Co2+, and Mn2+, did not affect cosR transcription, suggesting that cosR transcription is regulated specifically by iron. Interestingly, the level of perR transcription was increased when CosR was overexpressed. The positive regulation of perR transcription by CosR was observed both in the presence or in the absence of iron. The results of the electrophoretic mobility shift assay showed that CosR directly binds to the perR promoter. DNase I footprinting assays revealed that the CosR binding site in the perR promoter overlaps with the PerR box. In the study, we demonstrated that cosR transcription is increased in iron-rich conditions, and CosR positively regulates the transcription of PerR, another important regulator of oxidative stress defense in C. jejuni. These results provide new insight into how C. jejuni regulates oxidative stress defense by coordinating the transcription of perR and cosR in response to iron.
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Affiliation(s)
- Myungseo Park
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Sunyoung Hwang
- Department of Food and Animal Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
- Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
- Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Center for Food Bioconvergence, Seoul National University, Seoul 08826, Korea
- Correspondence: (S.R.); (B.J.)
| | - Byeonghwa Jeon
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN 55455, USA;
- Correspondence: (S.R.); (B.J.)
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9
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Duqué B, Rezé S, Rossero A, Membré JM, Guillou S, Haddad N. Quantification of Campylobacter jejuni gene expression after successive stresses mimicking poultry slaughtering steps. Food Microbiol 2021; 98:103795. [PMID: 33875223 DOI: 10.1016/j.fm.2021.103795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/05/2021] [Accepted: 03/23/2021] [Indexed: 12/31/2022]
Abstract
Broiler meat is considered as the most important source of the foodborne pathogen Campylobacter jejuni. Exposure to stress conditions encountered during the slaughtering process may induce bacterial adaptation mechanisms, and enhance or decrease pathogen resistance to subsequent stress. This adaptation may result from changes in bacterial gene expression. This study aims to accurately quantify the expression of selected C. jejuni genes after stresses inspired from the poultry slaughtering process. RT-qPCR was used to quantify gene expression of 44 genes in three strains after successive heat and cold stresses. Main results indicated that 26 genes out of 44 were differentially expressed following the successive thermal stresses. Three clusters of genes were differentially expressed according to the strain and the stress condition. Up-regulated genes mainly included genes involved in the heat shock response, whereas down-regulated genes belonged to metabolic pathways (such as lipid, amino-acid metabolisms). However, four genes were similarly overexpressed in the three strains; they might represent indicators of the thermal stress response at the species scale. Advances in the molecular understanding of the stress response of pathogenic bacteria, such as Campylobacter, in real-life processing conditions will make it possible to identify technological levers and better mitigate the microbial risk.
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Affiliation(s)
- Benjamin Duqué
- SECALIM, INRAE, Oniris, Université Bretagne Loire, 44307, Nantes, France
| | - Sandrine Rezé
- SECALIM, INRAE, Oniris, Université Bretagne Loire, 44307, Nantes, France
| | - Albert Rossero
- SECALIM, INRAE, Oniris, Université Bretagne Loire, 44307, Nantes, France
| | | | - Sandrine Guillou
- SECALIM, INRAE, Oniris, Université Bretagne Loire, 44307, Nantes, France
| | - Nabila Haddad
- SECALIM, INRAE, Oniris, Université Bretagne Loire, 44307, Nantes, France.
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10
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Baarda BI, Zielke RA, Le Van A, Jerse AE, Sikora AE. Neisseria gonorrhoeae MlaA influences gonococcal virulence and membrane vesicle production. PLoS Pathog 2019; 15:e1007385. [PMID: 30845186 PMCID: PMC6424457 DOI: 10.1371/journal.ppat.1007385] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 03/19/2019] [Accepted: 02/11/2019] [Indexed: 02/07/2023] Open
Abstract
The six-component maintenance of lipid asymmetry (Mla) system is responsible for retrograde transport of phospholipids, ensuring the barrier function of the Gram-negative cell envelope. Located within the outer membrane, MlaA (VacJ) acts as a channel to shuttle phospholipids from the outer leaflet. We identified Neisseria gonorrhoeae MlaA (ngo2121) during high-throughput proteomic mining for potential therapeutic targets against this medically important human pathogen. Our follow-up phenotypic microarrays revealed that lack of MlaA results in a complex sensitivity phenome. Herein we focused on MlaA function in cell envelope biogenesis and pathogenesis. We demonstrate the existence of two MlaA classes among 21 bacterial species, characterized by the presence or lack of a lipoprotein signal peptide. Purified truncated N. gonorrhoeae MlaA elicited antibodies that cross-reacted with a panel of different Neisseria. Little is known about MlaA expression; we provide the first evidence that MlaA levels increase in stationary phase and under anaerobiosis but decrease during iron starvation. Lack of MlaA resulted in higher cell counts during conditions mimicking different host niches; however, it also significantly decreased colony size. Antimicrobial peptides such as polymyxin B exacerbated the size difference while human defensin was detrimental to mutant viability. Consistent with the proposed role of MlaA in vesicle biogenesis, the ΔmlaA mutant released 1.7-fold more membrane vesicles. Comparative proteomics of cell envelopes and native membrane vesicles derived from ΔmlaA and wild type bacteria revealed enrichment of TadA–which recodes proteins through mRNA editing–as well as increased levels of adhesins and virulence factors. MlaA-deficient gonococci significantly outcompeted (up to 16-fold) wild-type bacteria in the murine lower genital tract, suggesting the growth advantage or increased expression of virulence factors afforded by inactivation of mlaA is advantageous in vivo. Based on these results, we propose N. gonorrhoeae restricts MlaA levels to modulate cell envelope homeostasis and fine-tune virulence. The Gram-negative outer membrane is a formidable barrier, primarily because of its asymmetric composition. A layer of lipopolysaccharide is exposed to the external environment and phospholipids are on the internal face of the outer membrane. MlaA is part of a bacterial system that prevents phospholipid accumulation within the lipopolysaccharide layer. If MlaA is removed, membrane asymmetry is disrupted and bacteria become more vulnerable to certain antimicrobials. Neisseria gonorrhoeae causes millions of infections worldwide annually. A growing number are resistant to available antibiotics. Improving our understanding of gonococcal pathogenicity and basic biological processes is required to facilitate the discovery of new weapons against gonorrhea. We investigated the role of MlaA in N. gonorrhoeae and found that when MlaA was absent, bacteria were more sensitive to antibiotics and human defensins. However, the mutant bacteria produced more membrane vesicles–packages of proteins wrapped in membrane material. Mutant vesicles and cell envelopes were enriched in proteins that contribute to disease. These alterations significantly increased mutant fitness during experimental infection of the female mouse genital tract. Our results provide new insights into the processes N. gonorrhoeae uses to fine-tune its ability to stay fit in the hostile environment of the genital tract.
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Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
| | - Adriana Le Van
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Ann E. Jerse
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America
- * E-mail:
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11
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Wheeler NE, Blackmore T, Reynolds AD, Midwinter AC, Marshall J, French NP, Savoian MS, Gardner PP, Biggs PJ. Genomic correlates of extraintestinal infection are linked with changes in cell morphology in Campylobacter jejuni. Microb Genom 2019; 5:e000251. [PMID: 30777818 PMCID: PMC6421344 DOI: 10.1099/mgen.0.000251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/16/2018] [Indexed: 12/12/2022] Open
Abstract
Campylobacter jejuni is the most common cause of bacterial diarrheal disease in the world. Clinical outcomes of infection can range from asymptomatic infection to life-threatening extraintestinal infections. This variability in outcomes for infected patients has raised questions as to whether genetic differences between C. jejuni isolates contribute to their likelihood of causing severe disease. In this study, we compare the genomes of ten C. jejuni isolates that were implicated in extraintestinal infections with reference gastrointestinal isolates, in order to identify unusual patterns of sequence variation associated with infection outcome. We identified a collection of genes that display a higher burden of uncommon mutations in invasive isolates compared with gastrointestinal close relatives, including some that have been previously linked to virulence and invasiveness in C. jejuni. Among the top genes identified were mreB and pgp1, which are both involved in determining cell shape. Electron microscopy confirmed morphological differences in isolates carrying unusual sequence variants of these genes, indicating a possible relationship between extraintestinal infection and changes in cell morphology.
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Affiliation(s)
- Nicole E. Wheeler
- Center for Genomic Pathogen Surveillance, Wellcome Sanger Institute, Hinxton, UK
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | | | - Angela D. Reynolds
- EpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Anne C. Midwinter
- EpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Jonathan Marshall
- EpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Nigel P. French
- EpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Palmerston North, New Zealand
| | - Matthew S. Savoian
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Paul P. Gardner
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, New Zealand.
| | - Patrick J. Biggs
- EpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- New Zealand Genomics Ltd (NZGL – as Massey Genome Service) Massey University, Palmerston North, New Zealand
- Allan Wilson Centre for Molecular Ecology and Evolution, Massey University, Palmerston North, New Zealand
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12
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Modulation of Haemophilus influenzae interaction with hydrophobic molecules by the VacJ/MlaA lipoprotein impacts strongly on its interplay with the airways. Sci Rep 2018; 8:6872. [PMID: 29720703 PMCID: PMC5932069 DOI: 10.1038/s41598-018-25232-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 04/13/2018] [Indexed: 01/02/2023] Open
Abstract
Airway infection by nontypeable Haemophilus influenzae (NTHi) associates to chronic obstructive pulmonary disease (COPD) exacerbation and asthma neutrophilic airway inflammation. Lipids are key inflammatory mediators in these disease conditions and consequently, NTHi may encounter free fatty acids during airway persistence. However, molecular information on the interplay NTHi-free fatty acids is limited, and we lack evidence on the importance of such interaction to infection. Maintenance of the outer membrane lipid asymmetry may play an essential role in NTHi barrier function and interaction with hydrophobic molecules. VacJ/MlaA-MlaBCDEF prevents phospholipid accumulation at the bacterial surface, being the only system involved in maintaining membrane asymmetry identified in NTHi. We assessed the relationship among the NTHi VacJ/MlaA outer membrane lipoprotein, bacterial and exogenous fatty acids, and respiratory infection. The vacJ/mlaA gene inactivation increased NTHi fatty acid and phospholipid global content and fatty acyl specific species, which in turn increased bacterial susceptibility to hydrophobic antimicrobials, decreased NTHi epithelial infection, and increased clearance during pulmonary infection in mice with both normal lung function and emphysema, maybe related to their shared lung fatty acid profiles. Altogether, we provide evidence for VacJ/MlaA as a key bacterial factor modulating NTHi survival at the human airway upon exposure to hydrophobic molecules.
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Lima WG, Alves MC, Cruz WS, Paiva MC. Chromosomally encoded and plasmid-mediated polymyxins resistance in Acinetobacter baumannii: a huge public health threat. Eur J Clin Microbiol Infect Dis 2018. [PMID: 29524060 DOI: 10.1007/s10096-018-3223-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen associated with nosocomial and community infections of great clinical relevance. Its ability to rapidly develop resistance to antimicrobials, especially carbapenems, has re-boosted the prescription and use of polymyxins. However, the emergence of strains resistant to these antimicrobials is becoming a critical issue in several regions of the world because very few of currently available antibiotics are effective in these cases. This review summarizes the most up-to-date knowledge about chromosomally encoded and plasmid-mediated polymyxins resistance in A. baumannii. Different mechanisms are employed by A. baumannii to overcome the antibacterial effects of polymyxins. Modification of the outer membrane through phosphoethanolamine addition, loss of lipopolysaccharide, symmetric rupture, metabolic changes affecting osmoprotective amino acids, and overexpression of efflux pumps are involved in this process. Several genetic elements modulate these mechanisms, but only three of them have been described so far in A. baumannii clinical isolates such as mutations in pmrCAB, lpxACD, and lpsB. Elucidation of genotypic profiles and resistance mechanisms are necessary for control and fight against resistance to polymyxins in A. baumannii, thereby protecting this class for future treatment.
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Affiliation(s)
- William Gustavo Lima
- Laboratory of Medical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Rua Sebastião Gonçalves Coelho, 400, Divinopolis, Minas Gerais, 35501-293, Brazil.
| | - Mara Cristina Alves
- Laboratory of Laboratorial Diagnostic and Clinical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Divinopolis, MG, Brazil
| | - Waleska Stephanie Cruz
- Laboratory of Molecular and Celular Biology, Alto Paraopeba Campus, Federal University of São João del-Rei, Ouro Branco, MG, Brazil
| | - Magna Cristina Paiva
- Laboratory of Laboratorial Diagnostic and Clinical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Divinopolis, MG, Brazil
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14
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Abstract
The function and extracellular location of cell envelope proteins make them attractive candidates for developing vaccines against bacterial diseases, including challenging drug-resistant pathogens, such as Neisseria gonorrhoeae A proteomics-driven reverse vaccinology approach has delivered multiple gonorrhea vaccine candidates; however, the biological functions of many of them remain to be elucidated. Herein, the functions of six gonorrhea vaccine candidates-NGO2121, NGO1985, NGO2054, NGO2111, NGO1205, and NGO1344-in cell envelope homeostasis were probed using phenotype microarrays under 1,056 conditions and a ΔbamE mutant (Δngo1780) as a reference of perturbed outer membrane integrity. Optimal growth conditions for an N. gonorrhoeae phenotype microarray assay in defined liquid medium were developed, which can be useful in other applications, including rapid and thorough antimicrobial susceptibility assessment. Our studies revealed 91 conditions having uniquely positive or negative effects on one of the examined mutants. A cluster analysis of 37 and 57 commonly beneficial and detrimental compounds, respectively, revealed three separate phenotype groups: NGO2121 and NGO1985; NGO1344 and BamE; and the trio of NGO1205, NGO2111, and NGO2054, with the last protein forming an independent branch of this cluster. Similar phenotypes were associated with loss of these vaccine candidates in the highly antibiotic-resistant WHO X strain. Based on their extensive sensitivity phenomes, NGO1985 and NGO2121 appear to be the most promising vaccine candidates. This study establishes the principle that phenotype microarrays can be successfully applied to a fastidious bacterial organism, such as N. gonorrhoeae IMPORTANCE Innovative approaches are required to develop vaccines against prevalent and neglected sexually transmitted infections, such as gonorrhea. Herein, we have utilized phenotype microarrays in the first such investigation into Neisseria gonorrhoeae to probe the function of proteome-derived vaccine candidates in cell envelope homeostasis. Information gained from this screening can feed the vaccine candidate decision tree by providing insights into the roles these proteins play in membrane permeability, integrity, and overall N. gonorrhoeae physiology. The optimized screening protocol can be applied in investigations into the function of other hypothetical proteins of N. gonorrhoeae discovered in the expanding number of whole-genome sequences, in addition to revealing phenotypic differences between clinical and laboratory strains.
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15
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Turonova H, Haddad N, Hernould M, Chevret D, Pazlarova J, Tresse O. Profiling of Campylobacter jejuni Proteome in Exponential and Stationary Phase of Growth. Front Microbiol 2017; 8:913. [PMID: 28572800 PMCID: PMC5435804 DOI: 10.3389/fmicb.2017.00913] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 05/04/2017] [Indexed: 12/25/2022] Open
Abstract
Campylobacter jejuni has been reported as a major cause of bacterial food-borne enteritides in developed countries during the last decade. Despite its fastidious growth requirements, including low level of oxygen and high level of CO2, this pathogen is able to persist in the environment without permanent loss of its viability and virulence. As C. jejuni is not able to multiply outside a host, the cells spend significant amount of time in stationary phase of growth. The entry into the stationary phase is often correlated to resistance to various stresses in bacteria. The switching between exponential and stationary phases is frequently mediated by the regulator sigma S (RpoS). However, this factor is absent in C. jejuni and molecular mechanisms responsible for transition of cells to the stationary phase remain elusive. In this work, proteomic profiles of cells from exponential and stationary phases were compared using 2-D electrophoresis (2DE) fingerprinting combined with mass spectrometry analysis and qRT-PCR. The identified proteins, whose expression differed between the two phases, are mostly involved in protein biosynthesis, carbon metabolism, stress response and motility. Altered expression was observed also in the pleiotropic regulator CosR that was over-expressed during stationary phase. A shift between transcript and protein level evolution of CosR throughout the growth of C. jejuni was observed using qRT-PCR and (2DE). From these data, we hypothesized that CosR could undergo a negative autoregulation in stationary phase. A consensus sequence resulting from promoter sequence alignment of genes potentially regulated by CosR, including its own upstream region, among C. jejuni strains is proposed. To verify experimentally the potential autoregulation of CosR at the DNA level, electrophoretic mobility shift assay was performed with DNA fragments of CosR promoter region and rCosR. Different migration pattern of the promoter fragments indicates the binding capacity of CosR, suggesting its auto-regulation potential.
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Affiliation(s)
- Hana Turonova
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and TechnologyPrague, Czechia
| | - Nabila Haddad
- SECALIM UMR1014, Institut National de la Recherche AgronomiqueNantes, France
| | - Mathieu Hernould
- SECALIM UMR1014, Institut National de la Recherche AgronomiqueNantes, France
| | - Didier Chevret
- UMR1319 MICALIS, Plateforme d'Analyse Protéomique de Paris Sud-Ouest, Institut National de la Recherche AgronomiqueJouy-en-Josas, France
| | - Jarmila Pazlarova
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and TechnologyPrague, Czechia
| | - Odile Tresse
- SECALIM UMR1014, Institut National de la Recherche AgronomiqueNantes, France
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16
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Flint A, Stintzi A, Saraiva LM. Oxidative and nitrosative stress defences of Helicobacter and Campylobacter species that counteract mammalian immunity. FEMS Microbiol Rev 2016; 40:938-960. [PMID: 28201757 PMCID: PMC5091033 DOI: 10.1093/femsre/fuw025] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/29/2016] [Accepted: 07/02/2016] [Indexed: 12/18/2022] Open
Abstract
Helicobacter and Campylobacter species are Gram-negative microaerophilic host-associated heterotrophic bacteria that invade the digestive tract of humans and animals. Campylobacter jejuni is the major worldwide cause of foodborne gastroenteritis in humans, while Helicobacter pylori is ubiquitous in over half of the world's population causing gastric and duodenal ulcers. The colonisation of the gastrointestinal system by Helicobacter and Campylobacter relies on numerous cellular defences to sense the host environment and respond to adverse conditions, including those imposed by the host immunity. An important antimicrobial tool of the mammalian innate immune system is the generation of harmful oxidative and nitrosative stresses to which pathogens are exposed during phagocytosis. This review summarises the regulators, detoxifying enzymes and subversion mechanisms of Helicobacter and Campylobacter that ultimately promote the successful infection of humans.
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Affiliation(s)
- Annika Flint
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Alain Stintzi
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica, NOVA, Av. da República, 2780-157 Oeiras, Portugal
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Bronnec V, Turoňová H, Bouju A, Cruveiller S, Rodrigues R, Demnerova K, Tresse O, Haddad N, Zagorec M. Adhesion, Biofilm Formation, and Genomic Features of Campylobacter jejuni Bf, an Atypical Strain Able to Grow under Aerobic Conditions. Front Microbiol 2016; 7:1002. [PMID: 27446042 PMCID: PMC4927563 DOI: 10.3389/fmicb.2016.01002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/13/2016] [Indexed: 12/29/2022] Open
Abstract
Campylobacter jejuni is the leading cause of bacterial enteritis in Europe. Human campylobacteriosis cases are frequently associated to the consumption of contaminated poultry meat. To survive under environmental conditions encountered along the food chain, i.e., from poultry digestive tract its natural reservoir to the consumer's plate, this pathogen has developed adaptation mechanisms. Among those, biofilm lifestyle has been suggested as a strategy to survive in the food environment and under atmospheric conditions. Recently, the clinical isolate C. jejuni Bf has been shown to survive and grow under aerobic conditions, a property that may help this strain to better survive along the food chain. The aim of this study was to evaluate the adhesion capacity of C. jejuni Bf and its ability to develop a biofilm. C. jejuni Bf can adhere to abiotic surfaces and to human epithelial cells, and can develop biofilm under both microaerobiosis and aerobiosis. These two conditions have no influence on this strain, unlike results obtained with the reference strain C. jejuni 81-176, which harbors only planktonic cells under aerobic conditions. Compared to 81-176, the biofilm of C. jejuni Bf is more homogenous and cell motility at the bottom of biofilm was not modified whatever the atmosphere used. C. jejuni Bf whole genome sequence did not reveal any gene unique to this strain, suggesting that its unusual property does not result from acquisition of new genetic material. Nevertheless some genetic particularities seem to be shared only between Bf and few others strains. Among the main features of C. jejuni Bf genome we noticed (i) a complete type VI secretion system important in pathogenicity and environmental adaptation; (ii) a mutation in the oorD gene involved in oxygen metabolism; and (iii) the presence of an uncommon insertion of a 72 amino acid coding sequence upstream from dnaK, which is involved in stress resistance. Therefore, the atypical behavior of this strain under aerobic atmosphere may result from the combination of insertions and mutations. In addition, the comparison of mRNA transcript levels of several genes targeted through genome analysis suggests the modification of regulatory processes in this strain.
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Affiliation(s)
| | - Hana Turoňová
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and MicrobiologyPrague, Czech Republic
| | | | - Stéphane Cruveiller
- CNRS-UMR 8030 and Commissariat à l’Energie Atomique et aux Energies Alternatives CEA/DRF/IG/Genoscope LABGeMEvry, France
| | | | - Katerina Demnerova
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and MicrobiologyPrague, Czech Republic
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18
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Koolman L, Whyte P, Burgess C, Bolton D. Virulence gene expression, adhesion and invasion of Campylobacter jejuni exposed to oxidative stress (H2O2). Int J Food Microbiol 2016; 220:33-8. [DOI: 10.1016/j.ijfoodmicro.2016.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/04/2016] [Accepted: 01/06/2016] [Indexed: 11/24/2022]
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19
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Rodrigues RC, Pocheron AL, Hernould M, Haddad N, Tresse O, Cappelier JM. Description of Campylobacter jejuni Bf, an atypical aero-tolerant strain. Gut Pathog 2015; 7:30. [PMID: 26594244 PMCID: PMC4653858 DOI: 10.1186/s13099-015-0077-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/05/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Campylobacter jejuni is a leading cause of bacterial enteritis worldwide. This microaerophilic bacterium can survive in aerobic environments, suggesting it has protective mechanisms against oxidative stress. The clinical C. jejuni Bf strain is characterized by an increased resistance to oxygen. This study aimed to characterize the behavior of the clinical C. jejuni Bf strain under an aerobic atmosphere and in response to ROS-promoter agents. METHODS Growth was studied in both aerobic and microaerobic conditions using classic cultivable methods. Electronic microscopy and mreB gene expression were used to evaluate the morphology of this strain under aerobic conditions. The survival under oxidative stress was tested in the presence of different concentrations of hydrogen peroxide (H2O2) and paraquat (PQ). RESULTS The results showed that C. jejuni Bf strain can grow aerobically, unlike other strains of C. jejuni tested. Cells of C. jejuni Bf exposed to oxidative stress presented changes in morphology and the gene mreB, responsible for maintaining the bacillary cell morphology, was down-expressed. In aerobically acclimated conditions, C. jejuni Bf exhibited a higher survival rate of 52 % in the presence of H2O2 (1 mM) compared to the reference strain NCTC 11168. Concentrations above 1 mM PQ were lethal for the reference strain but not for C. jejuni Bf. CONCLUSIONS Taken together, these data highlight the resistance to oxidative stress conditions of C. jejuni Bf, indicating that this microorganism seems more adapted to survival in hostile environmental conditions.
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Affiliation(s)
- Ramila Cristiane Rodrigues
- />ONIRIS National College of Veterinary Medicine, Food Science and Engineering, Route de Gachet - La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France
- />Institut National de la Recherche Agronomique (INRA), Rue de la Geraudière, 44000 Nantes, France
| | - Anne-Lise Pocheron
- />ONIRIS National College of Veterinary Medicine, Food Science and Engineering, Route de Gachet - La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France
- />Institut National de la Recherche Agronomique (INRA), Rue de la Geraudière, 44000 Nantes, France
| | - Mathieu Hernould
- />ONIRIS National College of Veterinary Medicine, Food Science and Engineering, Route de Gachet - La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France
- />Institut National de la Recherche Agronomique (INRA), Rue de la Geraudière, 44000 Nantes, France
| | - Nabila Haddad
- />ONIRIS National College of Veterinary Medicine, Food Science and Engineering, Route de Gachet - La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France
- />Institut National de la Recherche Agronomique (INRA), Rue de la Geraudière, 44000 Nantes, France
| | - Odile Tresse
- />ONIRIS National College of Veterinary Medicine, Food Science and Engineering, Route de Gachet - La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France
- />Institut National de la Recherche Agronomique (INRA), Rue de la Geraudière, 44000 Nantes, France
| | - Jean-Michel Cappelier
- />ONIRIS National College of Veterinary Medicine, Food Science and Engineering, Route de Gachet - La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France
- />Institut National de la Recherche Agronomique (INRA), Rue de la Geraudière, 44000 Nantes, France
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20
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Varsaki A, Murphy C, Barczynska A, Jordan K, Carroll C. The acid adaptive tolerance response in Campylobacter jejuni induces a global response, as suggested by proteomics and microarrays. Microb Biotechnol 2015. [PMID: 26221965 PMCID: PMC4621450 DOI: 10.1111/1751-7915.12302] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Campylobacter jejuni CI 120 is a natural isolate obtained during poultry processing and has the ability to induce an acid tolerance response (ATR) to acid + aerobic conditions in early stationary phase. Other strains tested they did not induce an ATR or they induced it in exponential phase. Campylobacter spp. do not contain the genes that encode the global stationary phase stress response mechanism. Therefore, the aim of this study was to identify genes that are involved in the C. jejuni CI 120 early stationary phase ATR, as it seems to be expressing a novel mechanism of stress tolerance. Two-dimensional gel electrophoresis was used to examine the expression profile of cytosolic proteins during the C. jejuni CI 120 adaptation to acid + aerobic stress and microarrays to determine the genes that participate in the ATR. The results indicate induction of a global response that activated a number of stress responses, including several genes encoding surface components and genes involved with iron uptake. The findings of this study provide new insights into stress tolerance of C. jejuni, contribute to a better knowledge of the physiology of this bacterium and highlight the diversity among different strains.
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Affiliation(s)
- Athanasia Varsaki
- Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Caroline Murphy
- Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland.,Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | - Alicja Barczynska
- Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Kieran Jordan
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | - Cyril Carroll
- Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
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21
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Kim JC, Oh E, Kim J, Jeon B. Regulation of oxidative stress resistance in Campylobacter jejuni, a microaerophilic foodborne pathogen. Front Microbiol 2015; 6:751. [PMID: 26284041 PMCID: PMC4518328 DOI: 10.3389/fmicb.2015.00751] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/08/2015] [Indexed: 12/31/2022] Open
Abstract
Campylobacter jejuni is one of the leading bacterial causes of human gastroenteritis. Due to the increasing rates of human campylobacteriosis, C. jejuni is considered as a serious public health concern worldwide. C. jejuni is a microaerophilic, fastidious bacterium. C. jejuni must overcome a wide range of stress conditions during foodborne transmission to humans, such as food preservation and processing conditions, and even in infection of the gastrointestinal tracts of humans. Particularly, this microaerophilic foodborne pathogen must survive in the atmospheric conditions prior to the initiation of infection. C. jejuni possesses unique regulatory mechanisms for oxidative stress resistance. Lacking OxyR and SoxRS that are highly conserved in other Gram-negative foodborne pathogens, C. jejuni modulates the expression of genes involved in oxidative stress resistance mainly via the peroxide resistance regulator and Campylobacter oxidative stress regulator. Based on recent findings of ours and others, in this review, we described how C. jejuni regulates the expression of oxidative stress defense.
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Affiliation(s)
| | | | | | - Byeonghwa Jeon
- School of Public Health, University of Alberta, EdmontonAB, Canada
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22
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Macé S, Haddad N, Zagorec M, Tresse O. Influence of measurement and control of microaerobic gaseous atmospheres in methods for Campylobacter growth studies. Food Microbiol 2015; 52:169-76. [PMID: 26338132 DOI: 10.1016/j.fm.2015.07.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/19/2015] [Accepted: 07/22/2015] [Indexed: 10/23/2022]
Abstract
Campylobacter is the leading cause of bacterial enteritis in the world. For this reason, this pathogen is widely studied. As a microaerophilic and capnophilic microorganism, this foodborne pathogen requires an atmosphere with reduced oxygen (O2) and elevated carbon dioxide (CO2) concentrations for its optimal growth in vitro. According to the procedure for Campylobacter spp. isolation and cultivation from food products and environmental samples, European and American standards recommend gas proportions of 5% O2 and 10% CO2, complemented with nitrogen (N2). However, in the literature, the reported proportion of O2 for microaerobic growth conditions of Campylobacter spp. can range from 2.5% to 15% and the reason for this variation is usually not explained. The use of different gas generating systems and media to detect and to grow Campylobacter from foodstuff and the lack of information about gas producing systems are the main sources of the loss of consistancy between data. In this review, the relevance, strengths and weaknesses of these methods and their impact on Campylobacter biology are discussed. In conclusion the minimum information concerning microaerobic gaseous atmospheres are suggested in order to better harmonize data obtained from research studies for a better understanding of Campylobacter features.
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Affiliation(s)
- Sabrina Macé
- INRA, UMR 1014 Secalim, Nantes, F-44307, France; LUNAM Université, Oniris, Nantes, F-44307, France
| | - Nabila Haddad
- INRA, UMR 1014 Secalim, Nantes, F-44307, France; LUNAM Université, Oniris, Nantes, F-44307, France
| | - Monique Zagorec
- INRA, UMR 1014 Secalim, Nantes, F-44307, France; LUNAM Université, Oniris, Nantes, F-44307, France
| | - Odile Tresse
- INRA, UMR 1014 Secalim, Nantes, F-44307, France; LUNAM Université, Oniris, Nantes, F-44307, France.
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23
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Turonova H, Briandet R, Rodrigues R, Hernould M, Hayek N, Stintzi A, Pazlarova J, Tresse O. Biofilm spatial organization by the emerging pathogen Campylobacter jejuni: comparison between NCTC 11168 and 81-176 strains under microaerobic and oxygen-enriched conditions. Front Microbiol 2015. [PMID: 26217332 PMCID: PMC4499754 DOI: 10.3389/fmicb.2015.00709] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
During the last years, Campylobacter has emerged as the leading cause of bacterial foodborne infections in developed countries. Described as an obligate microaerophile, Campylobacter has puzzled scientists by surviving a wide range of environmental oxidative stresses on foods farm to retail, and thereafter intestinal transit and oxidative damage from macrophages to cause human infection. In this study, confocal laser scanning microscopy (CLSM) was used to explore the biofilm development of two well-described Campylobacter jejuni strains (NCTC 11168 and 81-176) prior to or during cultivation under oxygen-enriched conditions. Quantitative and qualitative appraisal indicated that C. jejuni formed finger-like biofilm structures with an open ultrastructure for 81-176 and a multilayer-like structure for NCTC 11168 under microaerobic conditions (MAC). The presence of motile cells within the biofilm confirmed the maturation of the C. jejuni 81-176 biofilm. Acclimation of cells to oxygen-enriched conditions led to significant enhancement of biofilm formation during the early stages of the process. Exposure to these conditions during biofilm cultivation induced an even greater biofilm development for both strains, indicating that oxygen demand for biofilm formation is higher than for planktonic growth counterparts. Overexpression of cosR in the poorer biofilm-forming strain, NCTC 11168, enhanced biofilm development dramatically by promoting an open ultrastructure similar to that observed for 81-176. Consequently, the regulator CosR is likely to be a key protein in the maturation of C. jejuni biofilm, although it is not linked to oxygen stimulation. These unexpected data advocate challenging studies by reconsidering the paradigm of fastidious requirements for C. jejuni growth when various subpopulations (from quiescent to motile cells) coexist in biofilms. These findings constitute a clear example of a survival strategy used by this emerging human pathogen.
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Affiliation(s)
- Hana Turonova
- SECALIM UMR1014, Institut National de la Recherche Agronomique Nantes, France ; LUNAM Université, Oniris, Université de Nantes Nantes, France ; Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Czech Republic
| | - Romain Briandet
- MICALIS UMR1319, Institut National de la Recherche Agronomique Massy, France
| | - Ramila Rodrigues
- SECALIM UMR1014, Institut National de la Recherche Agronomique Nantes, France ; LUNAM Université, Oniris, Université de Nantes Nantes, France
| | | | - Nabil Hayek
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa Ottawa, ON, Canada
| | - Alain Stintzi
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa Ottawa, ON, Canada
| | - Jarmila Pazlarova
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Czech Republic
| | - Odile Tresse
- SECALIM UMR1014, Institut National de la Recherche Agronomique Nantes, France ; LUNAM Université, Oniris, Université de Nantes Nantes, France
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Koolman L, Whyte P, Burgess C, Bolton D. Distribution of virulence-associated genes in a selection of Campylobacter isolates. Foodborne Pathog Dis 2015; 12:424-32. [PMID: 25826607 DOI: 10.1089/fpd.2014.1883] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
This study tested 24 Campylobacter isolates for the presence of 35 virulence genes using the polymerase chain reaction. The target genes included those involved in motility (flaA, flaB, flhA, flhB, flgB, flgE2, fliM, fliY), chemotaxis (cheA, cheB, cheR, cheW, cheY, cheZ), cell adhesion (cadF, dnaJ, jlpA, pldA, racR, virB11), invasion (iamA, ciaB, ceuE), cytotoxin production (cdtA, cdtB, cdtC, wlaN), capsule (kpsM), multidrug and bile resistance (cmeA, cmeB, cmeC), stress response/survival (katA, sodB), and the iron uptake system (cfrA, fur). The motility genes (with the exception of flaB), the CmeABC efflux system, cdtABC genes, and the sodB gene were commonly distributed among Campylobacter strains while the virB11 and wlaN genes were rarely detected. Interestingly, the findings suggest that flaB is not essential for full motility and C. coli lacking the flhA gene may be highly invasive. This study provides additional information on the distribution of Campylobacter virulence factors and the effect of their presence/absence on adhesion and invasion. It will inform future studies designed to elucidate the exact mechanisms of pathogenesis in Campylobacter.
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Affiliation(s)
- Leonard Koolman
- 1 Food Safety Department, Teagasc Food Research Centre , Ashtown, Dublin, Ireland
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25
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Bronowski C, James CE, Winstanley C. Role of environmental survival in transmission of Campylobacter jejuni. FEMS Microbiol Lett 2014; 356:8-19. [PMID: 24888326 DOI: 10.1111/1574-6968.12488] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/20/2014] [Accepted: 05/24/2014] [Indexed: 11/29/2022] Open
Abstract
Campylobacter species are the most common cause of bacterial gastroenteritis, with C. jejuni responsible for the majority of these cases. Although it is clear that livestock, and particularly poultry, are the most common source, it is likely that the natural environment (soil and water) plays a key role in transmission, either directly to humans or indirectly via farm animals. It has been shown using multilocus sequence typing that some clonal complexes (such as ST-45) are more frequently isolated from environmental sources such as water, suggesting that strains vary in their ability to survive in the environment. Although C. jejuni are fastidious microaerophiles generally unable to grow in atmospheric levels of oxygen, C. jejuni can adapt to survival in the environment, exhibiting aerotolerance and starvation survival. Biofilm formation, the viable but nonculturable state, and interactions with other microorganisms can all contribute to survival outside the host. By exploiting high-throughput technologies such as genome sequencing and RNA Seq, we are well placed to decipher the mechanisms underlying the variations in survival between strains in environments such as soil and water and to better understand the role of environmental persistence in the transmission of C. jejuni directly or indirectly to humans.
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Affiliation(s)
- Christina Bronowski
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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26
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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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27
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Kassem II, Khatri M, Sanad YM, Wolboldt M, Saif YM, Olson JW, Rajashekara G. The impairment of methylmenaquinol:fumarate reductase affects hydrogen peroxide susceptibility and accumulation in Campylobacter jejuni. Microbiologyopen 2014; 3:168-81. [PMID: 24515965 PMCID: PMC3996566 DOI: 10.1002/mbo3.158] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 12/07/2013] [Accepted: 12/26/2013] [Indexed: 12/18/2022] Open
Abstract
The methylmenaquinol:fumarate reductase (Mfr) of Campylobacter jejuni is a periplasmic respiratory (redox) protein that contributes to the metabolism of fumarate and displays homology to succinate dehydrogenase (Sdh). Since chemically oxidized redox-enzymes, including fumarate reductase and Sdh, contribute to the generation of oxidative stress in Escherichia coli, we assessed the role of Mfr in C. jejuni after exposure to hydrogen peroxide (H2 O2 ). Our results show that a Mfr mutant (∆mfrA) strain was less susceptible to H2 O2 as compared to the wildtype (WT). Furthermore, the H2 O2 concentration in the ∆mfrA cultures was significantly higher than that of WT after exposure to the oxidant. In the presence of H2 O2 , catalase (KatA) activity and katA expression were significantly lower in the ∆mfrA strain as compared to the WT. Exposure to H2 O2 resulted in a significant decrease in total intracellular iron in the ∆mfrA strain as compared to WT, while the addition of iron to the growth medium mitigated H2 O2 susceptibility and accumulation in the mutant. The ∆mfrA strain was significantly more persistent in RAW macrophages as compared to the WT. Scanning electron microscopy showed that infection with the ∆mfrA strain caused prolonged changes to the macrophages' morphology, mainly resulting in spherical-shaped cells replete with budding structures and craters. Collectively, our results suggest a role for Mfr in maintaining iron homeostasis in H2 O2 stressed C. jejuni, probably via affecting the concentrations of intracellular iron.
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Affiliation(s)
- Issmat I Kassem
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio
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28
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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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29
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Bratz K, Gölz G, Riedel C, Janczyk P, Nöckler K, Alter T. Inhibitory effect of high-dosage zinc oxide dietary supplementation on Campylobacter coli
excretion in weaned piglets. J Appl Microbiol 2013; 115:1194-202. [DOI: 10.1111/jam.12307] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/12/2013] [Accepted: 07/16/2013] [Indexed: 11/30/2022]
Affiliation(s)
- K. Bratz
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
| | - G. Gölz
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
| | - C. Riedel
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
| | - P. Janczyk
- Federal Institute for Risk Assessment; Berlin Germany
| | - K. Nöckler
- Federal Institute for Risk Assessment; Berlin Germany
| | - T. Alter
- Institute of Food Hygiene; Freie Universität Berlin; Berlin Germany
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30
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Bauer S, Endres M, Lange M, Schmidt T, Schumbrutzki C, Sickmann A, Beier D. Novel function assignment to a member of the essential HP1043 response regulator family of epsilon-proteobacteria. Microbiology (Reading) 2013; 159:880-889. [DOI: 10.1099/mic.0.066548-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Susanne Bauer
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Michelle Endres
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Manuel Lange
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Theresa Schmidt
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Cornelia Schumbrutzki
- Leibnitz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Str. 6B, D-44227 Dortmund, Germany
| | - Albert Sickmann
- Leibnitz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Str. 6B, D-44227 Dortmund, Germany
| | - Dagmar Beier
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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31
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Transcriptional regulation of the CmeABC multidrug efflux pump and the KatA catalase by CosR in Campylobacter jejuni. J Bacteriol 2012; 194:6883-91. [PMID: 23065977 DOI: 10.1128/jb.01636-12] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
CosR is an essential response regulator in Campylobacter jejuni, a major food-borne pathogen causing enteritis worldwide. A transcriptomic analysis performed in this study discovered 93 genes whose transcriptional levels were changed >2-fold due to the repression of CosR expression by antisense peptide nucleic acid. The identified CosR-regulated genes are involved in various cellular functions, such as energy production, protein synthesis and folding, flagellum biogenesis, and lipid metabolism. Interestingly, 17 of the 93 CosR-regulated genes (18.3%) are predicted essential genes, indicating that CosR may participate in the regulation of vital biological processes in C. jejuni. In particular, CosR knockdown increased the transcriptional levels of cmeA, cmeB, and cmeC genes, whose protein product (CmeABC) is an important determinant conferring multidrug resistance in Campylobacter. Negative regulation of cmeABC by CosR was verified by quantitative real-time PCR (qRT-PCR) and P(cmeABC)::lacZ assay. The results of electrophoretic mobility shift assays (EMSAs) and DNase I footprinting assays demonstrated that CosR directly binds to the cmeABC promoter. Another notable finding is that CosR regulates the transcription of katA, the sole catalase gene in C. jejuni. Further characterization with qRT-PCR, the catalase enzyme assay, EMSA, and DNase I footprinting assays successfully demonstrated that CosR affects the katA transcription and the catalase activity by direct interactions with the katA promoter. The findings in this study clearly demonstrated that CosR regulates resistance mechanisms in C. jejuni by controlling the expression of genes involved in oxidative stress defense and extrusion of toxic compounds out of the cell.
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Sulaeman S, Hernould M, Schaumann A, Coquet L, Bolla JM, Dé E, Tresse O. Enhanced adhesion of Campylobacter jejuni to abiotic surfaces is mediated by membrane proteins in oxygen-enriched conditions. PLoS One 2012; 7:e46402. [PMID: 23029510 PMCID: PMC3460892 DOI: 10.1371/journal.pone.0046402] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 08/31/2012] [Indexed: 11/19/2022] Open
Abstract
Campylobacter jejuni is responsible for the major foodborne bacterial enteritis in humans. In contradiction with its fastidious growth requirements, this microaerobic pathogen can survive in aerobic food environments, suggesting that it must employ a variety of protection mechanisms to resist oxidative stress. For the first time, C. jejuni 81-176 inner and outer membrane subproteomes were analyzed separately using two-dimensional protein electrophoresis (2-DE) of oxygen-acclimated cells and microaerobically grown cells. LC-MS/MS analyses successfully identified 42 and 25 spots which exhibited a significantly altered abundance in the IMP-enriched fraction and in the OMP-enriched fraction, respectively, in response to oxidative conditions. These spots corresponded to 38 membrane proteins that could be grouped into different functional classes: (i) transporters, (ii) chaperones, (iii) fatty acid metabolism, (iv) adhesion/virulence and (v) other metabolisms. Some of these proteins were up-regulated at the transcriptional level in oxygen-acclimated cells as confirmed by qRT-PCR. Downstream analyses revealed that adhesion of C. jejuni to inert surfaces and swarming motility were enhanced in oxygen-acclimated cells or paraquat-stressed cells, which could be explained by the higher abundance of membrane proteins involved in adhesion and biofilm formation. The virulence factor CadF, over-expressed in the outer membrane of oxygen-acclimated cells, contributes to the complex process of C. jejuni adhesion to inert surfaces as revealed by a reduction in the capability of C. jejuni 81-176 ΔCadF cells compared to the isogenic strain.Taken together, these data demonstrate that oxygen-enriched conditions promote the over-expression of membrane proteins involved in both the biofilm initiation and virulence of C. jejuni.
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Affiliation(s)
- Sheiam Sulaeman
- INRA UMR1014 SECALIM, Nantes, France
- LUNAM Université, Oniris, Université de Nantes, Nantes, France
| | - Mathieu Hernould
- INRA UMR1014 SECALIM, Nantes, France
- LUNAM Université, Oniris, Université de Nantes, Nantes, France
| | - Annick Schaumann
- Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, UMR 6270 and FR 3038 CNRS, IFRMP23, Mont-Saint-Aignan, France
| | - Laurent Coquet
- Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, UMR 6270 and FR 3038 CNRS, IFRMP23, Mont-Saint-Aignan, France
| | - Jean-Michel Bolla
- UMR-MD1, Université de Aix-Marseille, IRBA, Facultés de Médecine et de Pharmacie, Marseille, France
| | - Emmanuelle Dé
- Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, UMR 6270 and FR 3038 CNRS, IFRMP23, Mont-Saint-Aignan, France
| | - Odile Tresse
- INRA UMR1014 SECALIM, Nantes, France
- LUNAM Université, Oniris, Université de Nantes, Nantes, France
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Drozd M, Gangaiah D, Liu Z, Rajashekara G. Contribution of TAT system translocated PhoX to Campylobacter jejuni phosphate metabolism and resilience to environmental stresses. PLoS One 2011; 6:e26336. [PMID: 22028859 PMCID: PMC3197622 DOI: 10.1371/journal.pone.0026336] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 09/25/2011] [Indexed: 12/12/2022] Open
Abstract
Campylobacter jejuni is a common gastrointestinal pathogen that colonizes food animals; it is transmitted via fecal contamination of food, and infections in immune-compromised people are more likely to result in serious long-term illness. Environmental phosphate is likely an important sensor of environmental fitness and the ability to obtain extracellular phosphate is central to the bacteria's core metabolic responses. PhoX is the sole alkaline phosphatase in C. jejuni, a substrate of the TAT transport system. Alkaline phosphatases mediate the hydrolytic removal of inorganic phosphate (Pi) from phospho-organic compounds and thereby contribute significantly to the polyphosphate kinase 1 (ppk1) mediated formation of poly P, a molecule that regulates bacterial response to stresses and virulence. Similarly, deletion of the tatC gene, a key component of the TAT system, results in diverse phenotypes in C. jejuni including reduced stress tolerance and in vivo colonization. Therefore, here we investigated the contribution of phoX in poly P synthesis and in TAT-system mediated responses. The phoX deletion mutant showed significant decrease (P<0.05) in poly P accumulation in stationary phase compared to the wild-type, suggesting that PhoX is a major contributor to the inorganic phosphate pool in the cell which is essential for poly P synthesis. The phoX deletion is sufficient for a nutrient stress defect similar to the defect previously described for the ΔtatC mutant. Additionally, the phoX deletion mutant has increased resistance to certain antimicrobials. The ΔphoX mutant was also moderately defective in invasion and intracellular survival within human intestinal epithelial cells as well as in chicken colonization. Further, the ΔphoX mutant produced increased biofilm that can be rescued with 1 mM inorganic phosphate. The qRT-PCR of the ΔphoX mutant revealed transcriptional changes that suggest potential mechanisms for the increased biofilm phenotype.
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Affiliation(s)
- Mary Drozd
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, United States of America
| | - Dharanesh Gangaiah
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, United States of America
| | - Zhe Liu
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, United States of America
| | - Gireesh Rajashekara
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, United States of America
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34
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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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35
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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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36
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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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Identification of essential genes in C. jejuni genome highlights hyper-variable plasticity regions. Funct Integr Genomics 2011; 11:241-57. [PMID: 21344305 DOI: 10.1007/s10142-011-0214-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 01/31/2011] [Accepted: 02/02/2011] [Indexed: 10/18/2022]
Abstract
A microarray transposon-based tracking approach was used to identify Campylobacter jejuni genes which are required for cell growth at 37°C, under a microaerophilic atmosphere and on a rich Mueller-Hinton medium. A transposon-based mutant library, comprised of 7,201 individual mutants was constructed, representing 4.48× coverage of the genome. An analysis of genes lacking a transposon insertion revealed 195 essential gene candidates. The function of these genes represent many of the expected core functions of the cell, such as energy metabolism, macromolecule and cofactor biosynthesis, cell structural proteins as well as basic cell processes. Forty-nine hypothetical proteins were also identified, further underlining the importance of currently unknown proteins and pathways within C. jejuni. Unlike other bacteria, the essential genes were not uniformly distributed along the chromosome with three main regions lacking essential genes. These particular regions corresponded to known hyper-variable plasticity regions of C. jejuni genome indicating, as expected, that these regions are dispensable in any given C. jejuni strain. Overall, this work identified dispensable and essential genes in C. jejuni that will ultimately lead to a better understanding of Campylobacter physiology.
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Profound differences in the transcriptome of Campylobacter jejuni grown in two different, widely used, microaerobic atmospheres. Res Microbiol 2011; 162:410-8. [PMID: 21320592 DOI: 10.1016/j.resmic.2011.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 01/19/2011] [Indexed: 11/23/2022]
Abstract
It was noted that quantitative and qualitative differences occurred between the growth of Campylobacter in microaerobic atmospheres provided by a gas replacement jar and that in a modular atmosphere controlled system cabinet, despite the fact that oxygen levels were comparable. Hydrogen was, however, only present in the replacement mixture (3%). Investigations were therefore carried out to examine any accompanying physiological or transcriptional differences. Growth curves and motility studies using Campylobacter jejuni HPC5 showed that cultures growing in the cabinet were impaired, but only in the early stages of growth compared to growth in the jar. However, transcriptome studies highlighted profound changes in the transcript profiles of exponential cultures grown in the cabinet compared to the jar, including genes indicative of oxidative stress. Genes involved in detoxification, synthesis and modification of macromolecules, probable prophage genes and genes associated with inhibition of natural transformation showed relative increases in expression in the cabinet. Conversely, genes that function in energy metabolism, chaperones, heat shock and motility were increased in the jar, which was indicative of balanced growth. This work highlights the need to carefully annotate the different methods of atmosphere generation in the description of experiments in microarray databases; the assessment of these experimental details is crucial to overcome difficulties in comparing transcriptomic studies of campylobacter cultures between different laboratories.
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Alazzam B, Bonnassie-Rouxin S, Dufour V, Ermel G. MCLMAN, a new minimal medium for Campylobacter jejuni NCTC 11168. Res Microbiol 2011; 162:173-9. [DOI: 10.1016/j.resmic.2010.09.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 09/19/2010] [Indexed: 11/29/2022]
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Adhesion ability of Campylobacter jejuni to Ht-29 cells increases with the augmentation of oxidant agent concentration. Curr Microbiol 2010; 61:500-5. [PMID: 20419374 DOI: 10.1007/s00284-010-9644-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 03/26/2010] [Indexed: 10/19/2022]
Abstract
Campylobacter jejuni (C. jejuni) is a leading cause of human enteritis worldwide and the most frequently reported zoonotic agent in the European Union. Despite the fact that C. jejuni is a microaerobic bacteria, known as a fragile one, it is able to survive through adverse conditions such as oxidative stress. The purpose of this study was first to test the oxidative stress resistance in 22 C. jejuni strains of various origins, and to compare adhesive and invasive abilities of four selected strains in the intestinal cell line Ht-29. Secondly, the effect of an oxidative stress on C. jejuni adhesion to Ht-29 cells was investigated. Results show that all the tested strains were able to survive after a 24-h incubation period in broth containing 10 μM of paraquat. From 12.5 μM of paraquat, bacterial strains exhibit different behaviour, and only three strains are able to survive at 25 μM of paraquat. In addition, this study revealed that the number of bound bacteria to epithelial cells increases with augmentation of paraquat concentration, suggesting a link between oxidative stress survival of C. jejuni and virulence on Ht-29 cells.
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Palyada K, Sun YQ, Flint A, Butcher J, Naikare H, Stintzi A. Characterization of the oxidative stress stimulon and PerR regulon of Campylobacter jejuni. BMC Genomics 2009; 10:481. [PMID: 19835633 PMCID: PMC2772861 DOI: 10.1186/1471-2164-10-481] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 10/18/2009] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND During gut colonization, the enteric pathogen Campylobacter jejuni must surmount the toxic effects of reactive oxygen species produced by its own metabolism, the host immune system, and intestinal microflora. Elucidation of C. jejuni oxidative stress defense mechanisms is critical for understanding Campylobacter pathophysiology. RESULTS The mechanisms of oxidative stress defense in C. jejuni were characterized by transcriptional profiling and phenotypic analysis of wild-type and mutant strains. To define the regulon of the peroxide-sensing regulator, PerR, we constructed an isogenic DeltaperR mutant and compared its transcriptome profile with that of the wild-type strain. Transcriptome profiling identified 104 genes that belonged to the PerR regulon. PerR appears to regulate gene expression in a manner that both depends on and is independent of the presence of iron and/or H2O2. Mutation of perR significantly reduced motility. A phenotypic analysis using the chick colonization model showed that the DeltaperR mutant exhibited attenuated colonization behavior. An analysis of changes in the transcriptome induced by exposure to H2O2, cumene hydroperoxide, or menadione revealed differential expression of genes belonging to a variety of biological pathways, including classical oxidative stress defense systems, heat shock response, DNA repair and metabolism, fatty acid biosynthesis, and multidrug efflux pumps. Mutagenic and phenotypic studies of the superoxide dismutase SodB, the alkyl-hydroxyperoxidase AhpC, and the catalase KatA, revealed a role for these proteins in oxidative stress defense and chick gut colonization. CONCLUSION This study reveals an interplay between PerR, Fur, iron metabolism and oxidative stress defense, and highlights the role of these elements in C. jejuni colonization of the chick cecum and/or subsequent survival.
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Affiliation(s)
- Kiran Palyada
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078, USA.
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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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Klančnik A, Guzej B, Jamnik P, Vučković D, Abram M, Možina SS. Stress response and pathogenic potential of Campylobacter jejuni cells exposed to starvation. Res Microbiol 2009; 160:345-52. [DOI: 10.1016/j.resmic.2009.05.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 04/30/2009] [Accepted: 05/04/2009] [Indexed: 10/20/2022]
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