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Tanoeiro L, Oleastro M, Nunes A, Marques AT, Duarte SV, Gomes JP, Matos APA, Vítor JMB, Vale FF. Cryptic Prophages Contribution for Campylobacter jejuni and Campylobacter coli Introgression. Microorganisms 2022; 10:microorganisms10030516. [PMID: 35336092 PMCID: PMC8955182 DOI: 10.3390/microorganisms10030516] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 11/23/2022] Open
Abstract
Campylobacter coli and C. jejuni, the causing agents of campylobacteriosis, are described to be undergoing introgression events, i.e., the transference of genetic material between different species, with some isolates sharing almost a quarter of its genome. The participation of phages in introgression events and consequent impact on host ecology and evolution remain elusive. Three distinct prophages, named C. jejuni integrated elements 1, 2, and 4 (CJIE1, CJIE2, and CJIE4), are described in C. jejuni. Here, we identified two unreported prophages, Campylobacter coli integrated elements 1 and 2 (CCIE1 and CCIE2 prophages), which are C. coli homologues of CJIE1 and CJIE2, respectively. No induction was achieved for both prophages. Conversely, induction assays on CJIE1 and CJIE2 point towards the inducibility of these prophages. CCIE2-, CJIE1-, and CJIE4-like prophages were identified in a Campylobacter spp. population of 840 genomes, and phylogenetic analysis revealed clustering in three major groups: CJIE1-CCIE1, CJIE2-CCIE2, and CJIE4, clearly segregating prophages from C. jejuni and C. coli, but not from human- and nonhuman-derived isolates, corroborating the flowing between animals and humans in the agricultural context. Punctual bacteriophage host-jumps were observed in the context of C. jejuni and C. coli, and although random chance cannot be fully discarded, these observations seem to implicate prophages in evolutionary introgression events that are modulating the hybridization of C. jejuni and C. coli species.
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Affiliation(s)
- Luís Tanoeiro
- Pathogen Genome Bioinformatics and Computational Biology, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (L.T.); (A.T.M.); (J.M.B.V.)
| | - Mónica Oleastro
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1600-609 Lisboa, Portugal;
| | - Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1600-609 Lisboa, Portugal; (A.N.); (J.P.G.)
| | - Andreia T. Marques
- Pathogen Genome Bioinformatics and Computational Biology, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (L.T.); (A.T.M.); (J.M.B.V.)
| | - Sílvia Vaz Duarte
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health Dr. Ricardo Jorge, 1600-609 Lisboa, Portugal;
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, 1600-609 Lisboa, Portugal; (A.N.); (J.P.G.)
| | - António Pedro Alves Matos
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Cooperativa de Ensino Superior Egas Moniz, Quinta da Granja, 2829-511 Caparica, Portugal;
| | - Jorge M. B. Vítor
- Pathogen Genome Bioinformatics and Computational Biology, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (L.T.); (A.T.M.); (J.M.B.V.)
| | - Filipa F. Vale
- Pathogen Genome Bioinformatics and Computational Biology, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisboa, Portugal; (L.T.); (A.T.M.); (J.M.B.V.)
- Correspondence: or
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Zampara A, Sørensen MCH, Gencay YE, Grimon D, Kristiansen SH, Jørgensen LS, Kristensen JR, Briers Y, Elsser-Gravesen A, Brøndsted L. Developing Innolysins Against Campylobacter jejuni Using a Novel Prophage Receptor-Binding Protein. Front Microbiol 2021; 12:619028. [PMID: 33597938 PMCID: PMC7882524 DOI: 10.3389/fmicb.2021.619028] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/11/2021] [Indexed: 11/13/2022] Open
Abstract
Campylobacter contaminated poultry remains the major cause of foodborne gastroenteritis worldwide, calling for novel antibacterials. We previously developed the concept of Innolysin composed of an endolysin fused to a phage receptor binding protein (RBP) and provided the proof-of-concept that Innolysins exert bactericidal activity against Escherichia coli. Here, we have expanded the Innolysin concept to target Campylobacter jejuni. As no C. jejuni phage RBP had been identified so far, we first showed that the H-fiber originating from a CJIE1-like prophage of C. jejuni CAMSA2147 functions as a novel RBP. By fusing this H-fiber to phage T5 endolysin, we constructed Innolysins targeting C. jejuni (Innolysins Cj). Innolysin Cj1 exerts antibacterial activity against diverse C. jejuni strains after in vitro exposure for 45 min at 20°C, reaching up to 1.30 ± 0.21 log reduction in CAMSA2147 cell counts. Screening of a library of Innolysins Cj composed of distinct endolysins for growth inhibition, allowed us to select Innolysin Cj5 as an additional promising antibacterial candidate. Application of either Innolysin Cj1 or Innolysin Cj5 on chicken skin refrigerated to 5°C and contaminated with C. jejuni CAMSA2147 led to 1.63 ± 0.46 and 1.18 ± 0.10 log reduction of cells, respectively, confirming that Innolysins Cj can kill C. jejuni in situ. The receptor of Innolysins Cj remains to be identified, however, the RBP component (H-fiber) recognizes a novel receptor compared to lytic phages binding to capsular polysaccharide or flagella. Identification of other unexplored Campylobacter phage RBPs may further increase the repertoire of new Innolysins Cj targeting distinct receptors and working as antibacterials against Campylobacter.
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Affiliation(s)
- Athina Zampara
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Yilmaz Emre Gencay
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dennis Grimon
- Department of Biotechnology, Ghent University, Ghent, Belgium
| | | | | | | | - Yves Briers
- Department of Biotechnology, Ghent University, Ghent, Belgium
| | | | - Lone Brøndsted
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
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Abstract
Thermophilic Campylobacter, in particular Campylobacter jejuni, C. coli and C. lari are the main relevant Campylobacter species for human infections. Due to their high capacity of genetic exchange by horizontal gene transfer (HGT), rapid adaptation to changing environmental and host conditions contribute to successful spreading and persistence of these foodborne pathogens. However, extensive HGT can exert dangerous side effects for the bacterium, such as the incorporation of gene fragments leading to disturbed gene functions. Here we discuss mechanisms of HGT, notably natural transformation, conjugation and bacteriophage transduction and limiting regulatory strategies of gene transfer. In particular, we summarize the current knowledge on how the DNA macromolecule is exchanged between single cells. Mechanisms to stimulate and to limit HGT obviously coevolved and maintained an optimal balance. Chromosomal rearrangements and incorporation of harmful mutations are risk factors for survival and can result in drastic loss of fitness. In Campylobacter, the restricted recognition and preferential uptake of free DNA from relatives are mediated by a short methylated DNA pattern and not by a classical DNA uptake sequence as found in other bacteria. A class two CRISPR-Cas system is present but also other DNases and restriction-modification systems appear to be important for Campylobacter genome integrity. Several lytic and integrated bacteriophages have been identified, which contribute to genome diversity. Furthermore, we focus on the impact of gene transfer on the spread of antibiotic resistance genes (resistome) and persistence factors. We discuss remaining open questions in the HGT field, supposed to be answered in the future by current technologies like whole-genome sequencing and single-cell approaches.
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Affiliation(s)
- Julia Carolin Golz
- Department of Biological Safety, National Reference Laboratory for Campylobacter, German Federal Institute for Risk Assessment (BfR), Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Kerstin Stingl
- Department of Biological Safety, National Reference Laboratory for Campylobacter, German Federal Institute for Risk Assessment (BfR), Diedersdorfer Weg 1, 12277, Berlin, Germany.
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Clark CG, Chen CY, Berry C, Walker M, McCorrister SJ, Chong PM, Westmacott GR. Comparison of genomes and proteomes of four whole genome-sequenced Campylobacter jejuni from different phylogenetic backgrounds. PLoS One 2018; 13:e0190836. [PMID: 29293692 PMCID: PMC5749857 DOI: 10.1371/journal.pone.0190836] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/20/2017] [Indexed: 12/13/2022] Open
Abstract
Whole genome sequencing (WGS) has been used to assess the phylogenetic relationships, virulence and metabolic differences, and the relationship between gene carriage and host or niche differentiation among populations of C. jejuni isolates. We previously characterized the presence and expression of CJIE4 prophage proteins in four C. jejuni isolates using WGS and comparative proteomics analysis, but the isolates were not assessed further. In this study we compare the closed, finished genome sequences of these isolates to the total proteome. Genomes of the four isolates differ in phage content and location, plasmid content, capsular polysaccharide biosynthesis loci, a type VI secretion system, orientation of the ~92 kb invertible element, and allelic differences. Proteins with 99% sequence identity can be differentiated using isobaric tags for relative and absolute quantification (iTRAQ) comparative proteomic methods. GO enrichment analysis and the type of artefacts produced in comparative proteomic analysis depend on whether proteins are encoded in only one isolate or common to all isolates, whether different isolates have different alleles of the proteins analyzed, whether conserved and variable regions are both present in the protein group analyzed, and on how the analysis is done. Several proteins encoded by genes with very high levels of sequence identity in all four isolates exhibited preferentially higher protein expression in only one of the four isolates, suggesting differential regulation among the isolates. It is possible to analyze comparative protein expression in more distantly related isolates in the context of WGS data, though the results are more complex to interpret than when isolates are clonal or very closely related. Comparative proteomic analysis produced log2 fold expression data suggestive of regulatory differences among isolates, indicating that it may be useful as a hypothesis generation exercise to identify regulated proteins and regulatory pathways for more detailed analysis.
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Affiliation(s)
- Clifford G. Clark
- Division of Enteric Diseases, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- * E-mail:
| | - Chih-yu Chen
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
- Bioinformatics Core, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Chrystal Berry
- Division of Enteric Diseases, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Matthew Walker
- Division of Enteric Diseases, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Stuart J. McCorrister
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Patrick M. Chong
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Garrett R. Westmacott
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
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Skarp CPA, Akinrinade O, Nilsson AJE, Ellström P, Myllykangas S, Rautelin H. Comparative genomics and genome biology of invasive Campylobacter jejuni. Sci Rep 2015; 5:17300. [PMID: 26603914 PMCID: PMC4658567 DOI: 10.1038/srep17300] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 10/28/2015] [Indexed: 12/28/2022] Open
Abstract
Campylobacter jejuni is a major pathogen in bacterial gastroenteritis worldwide and can cause bacteremia in severe cases. C. jejuni is highly structured into clonal lineages of which the ST677CC lineage has been overrepresented among C. jejuni isolates derived from blood. In this study, we characterized the genomes of 31 C. jejuni blood isolates and 24 faecal isolates belonging to ST677CC in order to study the genome biology related to C. jejuni invasiveness. We combined the genome analyses with phenotypical evidence on serum resistance which was associated with phase variation of wcbK; a GDP-mannose 4,6-dehydratase involved in capsular biosynthesis. We also describe the finding of a Type III restriction-modification system unique to the ST-794 sublineage. However, features previously considered to be related to pathogenesis of C. jejuni were either absent or disrupted among our strains. Our results refine the role of capsule features associated with invasive disease and accentuate the possibility of methylation and restriction enzymes in the potential of C. jejuni to establish invasive infections. Our findings underline the importance of studying clinically relevant well-characterized bacterial strains in order to understand pathogenesis mechanisms important in human infections.
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Affiliation(s)
- C. P. A. Skarp
- Department of Medical Sciences, Clinical Microbiology, Uppsala
University, Uppsala, Sweden
| | - O. Akinrinade
- Institute of Clinical Medicine, University of Helsinki,
Helsinki, Finland
- Institute of Biomedicine, University of Helsinki,
Helsinki, Finland
| | - A. J. E. Nilsson
- Department of Medical Sciences, Clinical Microbiology, Uppsala
University, Uppsala, Sweden
| | - P. Ellström
- Department of Medical Sciences, Clinical Microbiology, Uppsala
University, Uppsala, Sweden
| | - S. Myllykangas
- Institute of Biomedicine, University of Helsinki,
Helsinki, Finland
| | - H. Rautelin
- Department of Medical Sciences, Clinical Microbiology, Uppsala
University, Uppsala, Sweden
- Department of Bacteriology and Immunology, University of
Helsinki, Helsinki, Finland
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Clark CG, Chong PM, McCorrister SJ, Mabon P, Walker M, Westmacott GR. DNA sequence heterogeneity of Campylobacter jejuni CJIE4 prophages and expression of prophage genes. PLoS One 2014; 9:e95349. [PMID: 24756024 PMCID: PMC3995785 DOI: 10.1371/journal.pone.0095349] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/26/2014] [Indexed: 12/03/2022] Open
Abstract
Campylobacter jejuni carry temperate bacteriophages that can affect the biology or virulence of the host bacterium. Known effects include genomic rearrangements and resistance to DNA transformation. C. jejuni prophage CJIE1 shows sequence variability and variability in the content of morons. Homologs of the CJIE1 prophage enhance both adherence and invasion to cells in culture and increase the expression of a specific subset of bacterial genes. Other C. jejuni temperate phages have so far not been well characterized. In this study we describe investigations into the DNA sequence variability and protein expression in a second prophage, CJIE4. CJIE4 sequences were obtained de novo from DNA sequencing of five C. jejuni isolates, as well as from whole genome sequences submitted to GenBank by other research groups. These CJIE4 DNA sequences were heterogenous, with several different insertions/deletions (indels) in different parts of the prophage genome. Two variants of a 3–4 kb region inserted within CJIE4 had different gene content that distinguished two major conserved CJIE4 prophage families. Additional indels were detected throughout the prophage. Detection of proteins in the five isolates characterized in our laboratory in isobaric Tags for Relative and Absolute Quantitation (iTRAQ) experiments indicated that prophage proteins within each of the two large indel variants were expressed during growth of the bacteria on Mueller Hinton agar plates. These proteins included the extracellular DNase associated with resistance to DNA transformation and prophage repressor proteins. Other proteins associated with known or suspected roles in prophage biology were also expressed from CJIE4, including capsid protein, the phage integrase, and MazF, a type II toxin-antitoxin system protein. Together with the results previously obtained for the CJIE1 prophage these results demonstrate that sequence variability and expression of moron genes are both general properties of temperate bacteriophages in C. jejuni.
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Affiliation(s)
- Clifford G. Clark
- Enterics Diseases, Bacteriology and Enterics, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
- * E-mail:
| | - Patrick M. Chong
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Stuart J. McCorrister
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Philip Mabon
- Bioinformatics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Matthew Walker
- Enterics Diseases, Bacteriology and Enterics, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Garrett R. Westmacott
- Mass Spectrometry and Proteomics Core Facility, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
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Clark CG, Chong PM, McCorrister SJ, Simon P, Walker M, Lee DM, Nguy K, Cheng K, Gilmour MW, Westmacott GR. The CJIE1 prophage of Campylobacter jejuni affects protein expression in growth media with and without bile salts. BMC Microbiol 2014; 14:70. [PMID: 24641125 PMCID: PMC4004267 DOI: 10.1186/1471-2180-14-70] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 03/10/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The presence of Campylobacter jejuni temperate bacteriophages has increasingly been associated with specific biological effects. It has recently been demonstrated that the presence of the prophage CJIE1 is associated with increased adherence and invasion of C. jejuni isolates in cell culture assays. RESULTS Quantitative comparative proteomics experiments were undertaken using three closely related isolates with CJIE1 and one isolate without CJIE1 to determine whether there was a corresponding difference in protein expression levels. Initial experiments indicated that about 2% of the total proteins characterized were expressed at different levels in isolates with or without the prophage. Some of these proteins regulated by the presence of CJIE1 were associated with virulence or regulatory functions. Additional experiments were conducted using C. jejuni isolates with and without CJIE1 grown on four different media: Mueller Hinton (MH) media containing blood; MH media containing 0.1% sodium deoxycholate, which is thought to result in increased expression of virulence proteins; MH media containing 2.5% Oxgall; and MHwithout additives. These experiments provided further evidence that CJIE1 affected protein expression, including virulence-associated proteins. They also demonstrated a general bile response involving a majority of the proteome and clearly showed the induction of almost all proteins known to be involved with iron acquisition. The data have been deposited to the ProteomeXchange with identifiers PXD000798, PXD000799, PXD000800, and PXD000801. CONCLUSION The presence of the CJIE1 prophage was associated with differences in protein expression levels under different conditions. Further work is required to determine what genes are involved in causing this phenomenon.
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Affiliation(s)
- Clifford G Clark
- Enterics Research Section, Bacteriology and Enterics Program, National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington St, Winnipeg, Manitoba R3E 3R2, Canada.
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Janež N, Loc-Carrillo C. Use of phages to control Campylobacter spp. J Microbiol Methods 2013; 95:68-75. [PMID: 23830848 DOI: 10.1016/j.mimet.2013.06.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 06/22/2013] [Accepted: 06/25/2013] [Indexed: 01/21/2023]
Abstract
The use of phages to control pathogenic bacteria has been investigated since they were first discovered in the beginning of the 1900s. Over the last century we have slowly gained an in-depth understanding of phage biology including which phage properties are desirable when considering phage as biocontrol agents and which phage characteristics to potentially avoid. Campylobacter infections are amongst the most frequently encountered foodborne bacterial infections around the world. Handling and consumption of raw or undercooked poultry products have been determined to be the main route of transmission. The ability to use phages to target these bacteria has been studied for more than a decade and although we have made progress towards deciphering how best to use phages to control Campylobacter associated with poultry production, there is still much work to be done. This review outlines methods to improve the isolation of these elusive phages, as well as methods to identify desirable characteristics needed for a successful outcome. It also highlights the body of research undertaken so far and what criteria to consider when doing in-vivo studies, especially because some in-vitro studies have not been found to translate into to phage efficacy in-vivo.
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Affiliation(s)
- Nika Janež
- Laboratory of Bio-Analytics, Center of Excellence for Biosensors, Instrumentation and Process Control, Solkan, Slovenia
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Clark CG, Grant CCR, Pollari F, Marshall B, Moses J, Tracz DM, Gilmour MW. Effects of the Campylobacter jejuni CJIE1 prophage homologs on adherence and invasion in culture, patient symptoms, and source of infection. BMC Microbiol 2012; 12:269. [PMID: 23167543 PMCID: PMC3519530 DOI: 10.1186/1471-2180-12-269] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/12/2012] [Indexed: 09/03/2023] Open
Abstract
Background Prophages of enteric bacteria are frequently of key importance for the biology, virulence, or host adaptation of their host. Some C. jejuni isolates carry homologs of the CJIE1 (CMLP 1) prophage that carry cargo genes potentially involved in virulence. Possible role(s) of CJIE1 homologs in the biology and virulence of C. jejuni were therefore investigated by using in vitro cell culture assays and by assessing the association of C. jejuni isolates with and without these prophages with patients’ symptoms, with source, and with clonal lineages within the C. jejuni population. Results Four C. jejuni isolates, three carrying the CJIE1-like prophage and one without, were tested in cell culture assays for adherence and invasion. Both adherence and invasion of C. jejuni to cells in culture were increased by the presence of the CJIE1-family prophage. Differences in motility and growth rate did not appear to be responsible. The CJIE1 prophage was present in 23% of isolates from human and non-human sources combined that were obtained through sentinel-site surveillance, and the distribution of CJIE1 in this population showed modest clonal associations. There was no correlation between the presence of the CJIE1 prophage in C. jejuni and patient symptoms, although there was some statistical support for lower rates of abdominal pain and fever when the prophage was present. Little evidence was found for a role of the prophage in host adaptation or host specificity. Conclusion These biological effects suggest that the presence of the prophage may be a marker for differential virulence of some C. jejuni isolates. Ongoing research into the effects of the prophage on protein expression may provide additional insights into the roles the prophage may play in the biology of its host bacterium.
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Affiliation(s)
- Clifford G Clark
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba, R3E 3R2, Canada.
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