title: Campylobacter fetus Subspecies Contain Conserved Type IV Secretion Systems on Multiple Genomic Islands and Plasmids.
abstract: The features contributing to differences in pathogenicity of the Campylobacter fetus subspecies are unknown. Putative factors involved in pathogenesis are located in genomic islands that encode a type IV secretion system (T4SS) and fic domain (filamentation induced by cyclic AMP) proteins, which may disrupt host cell processes. In the genomes of 27 C. fetus strains, three phylogenetically-different T4SS-encoding regions (T4SSs) were identified: one was located in both the chromosome and in extra-chromosomal plasmids; one was located exclusively in the chromosome; and one exclusively in extra-chromosomal plasmids. We observed that C. fetus strains can contain multiple T4SSs and that homologous T4SSs can be present both in chromosomal genomic islands (GI) and on plasmids in the C. fetus strains. The GIs of the chromosomally located T4SS differed mainly by the presence of fic genes, insertion sequence elements and phage-related or hypothetical proteins. Comparative analysis showed that T4SS sequences, inserted in the same locations, were conserved in the studied C. fetus genomes. Using phylogenetic analysis of the T4SSs, it was shown that C. fetus may have acquired the T4SS regions from other Campylobacter species by horizontal gene transfer. The identified T4SSs and fic genes were found in Cff and Cfv strains, although the presence of T4SSs and fic genes were significantly associated with Cfv strains. The T4SSs and fic genes could not be associated with S-layer serotypes or geographical origin of the strains.
authors.affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.|WHO Collaborating Centre for Campylobacter / OIE Reference Laboratory for Campylobacteriosis, Utrecht, The Netherlands.
authors.forename: Linda van der
authors.initials: Lv
authors.lastname: Graaf-van Bloois
authors.affiliation: Produce Safety and Microbiology Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Albany, California, United States of America.
authors.forename: William G
authors.initials: WG
authors.lastname: Miller
authors.affiliation: Produce Safety and Microbiology Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Albany, California, United States of America.
authors.forename: Emma
authors.initials: E
authors.lastname: Yee
authors.affiliation: Institute of Pathology, Medical University of Graz, Graz, Austria.
authors.forename: Gregor
authors.initials: G
authors.lastname: Gorkiewicz
authors.affiliation: School of Medicine and Dentistry, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Forbes
authors.affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.|WHO Collaborating Centre for Campylobacter / OIE Reference Laboratory for Campylobacteriosis, Utrecht, The Netherlands.
authors.forename: Aldert L
authors.initials: AL
authors.lastname: Zomer
authors.affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.|WHO Collaborating Centre for Campylobacter / OIE Reference Laboratory for Campylobacteriosis, Utrecht, The Netherlands.|Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Jaap A
authors.initials: JA
authors.lastname: Wagenaar
authors.affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.|WHO Collaborating Centre for Campylobacter / OIE Reference Laboratory for Campylobacteriosis, Utrecht, The Netherlands.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Duim
mesh_terms: D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics; D002168:Campylobacter fetus / Q000235:genetics / Q000502:physiology*; D016680:Genome, Bacterial; D010802:Phylogeny; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins