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Sabine Kienesberger - One of the best experts on this subject based on the ideXlab platform.
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comparative genome analysis of campylobacter Fetus subspecies revealed horizontally acquired genetic elements important for virulence and niche specificity
PLOS ONE, 2014Co-Authors: Sabine Kienesberger, Hanna Sprenger, Stella Wolfgruber, Bettina Halwachs, Gerhard G Thallinger, Guillermo I Perezperez, Martin J. BlaserAbstract:Campylobacter Fetus are important animal and human pathogens and the two major subspecies differ strikingly in pathogenicity. C. Fetus subsp. venerealis is highly niche-adapted, mainly infecting the genital tract of cattle. C. Fetus subsp. Fetus has a wider host-range, colonizing the genital- and intestinal-tract of animals and humans. We report the complete genomic sequence of C. Fetus subsp. venerealis 84-112 and comparisons to the genome of C. Fetus subsp. Fetus 82-40. Functional analysis of genes predicted to be involved in C. Fetus virulence was performed. The two subspecies are highly syntenic with 92% sequence identity but C. Fetus subsp. venerealis has a larger genome and an extra-chromosomal element. Aside from apparent gene transfer agents and hypothetical proteins, the unique genes in both subspecies comprise two known functional groups: lipopolysaccharide production, and type IV secretion machineries. Analyses of lipopolysaccharide-biosynthesis genes in C. Fetus isolates showed linkage to particular pathotypes, and mutational inactivation demonstrated their roles in regulating virulence and host range. The comparative analysis presented here broadens knowledge of the genomic basis of C. Fetus pathogenesis and host specificity. It further highlights the importance of surface-exposed structures to C. Fetus pathogenicity and demonstrates how evolutionary forces optimize the fitness and host-adaptation of these pathogens.
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a genomic island defines subspecies specific virulence features of the host adapted pathogen campylobacter Fetus subsp venerealis
Journal of Bacteriology, 2010Co-Authors: Gregor Gorkiewicz, Sabine Kienesberger, Caroline Schober, Sylvia R Scheicher, Christian Gully, Rudolf Zechner, Ellen L ZechnerAbstract:The pathogen Campylobacter Fetus comprises two subspecies, C. Fetus subsp. Fetus and C. Fetus subsp. venerealis. Although these taxa are highly related on the genome level, they are adapted to distinct hosts and tissues. C. Fetus subsp. Fetus infects a diversity of hosts, including humans, and colonizes the gastrointestinal tract. In contrast, C. Fetus subsp. venerealis is largely restricted to the bovine genital tract, causing epidemic abortion in these animals. In light of their close genetic relatedness, the specific niche preferences make the C. Fetus subspecies an ideal model system to investigate the molecular basis of host adaptation. In this study, a subtractive-hybridization approach was applied to the genomes of the subspecies to identify different genes potentially underlying this specificity. The comparison revealed a genomic island uniquely present in C. Fetus subsp. venerealis that harbors several genes indicative of horizontal transfer and that encodes the core components necessary for bacterial type IV secretion. Macromolecular transporters of this type deliver effector molecules to host cells, thereby contributing to virulence in various pathogens. Mutational inactivation of the putative secretion system confirmed its involvement in the pathogenicity of C. Fetus subsp. venerealis.
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development of experimental genetic tools for campylobacter Fetus
Applied and Environmental Microbiology, 2007Co-Authors: Sabine Kienesberger, Gregor Gorkiewicz, Sylvia R Scheicher, Martina M Joainig, Eva Leitner, Ellen L ZechnerAbstract:Molecular analysis of the virulence mechanisms of the emerging pathogen Campylobacter Fetus has been hampered by the lack of genetic tools. We report the development and functional analysis of Escherichia coli-Campylobacter shuttle vectors that are appropriate for C. Fetus. Some vectors were constructed based on the known Campylobacter coli plasmid pIP1455 replicon, which confers a wide host range in Campylobacter spp. Versatility in directing gene expression was achieved by introducing a strong C. Fetus promoter. The constructions carry features necessary and sufficient to detect the expression of phenotypic markers, including molecular reporter genes in both subspecies of C. Fetus, while retaining function in C. jejuni. The capacity to express several gene products from different vectors in a single host can be advantageous but requires distinct plasmid replicons. To this end, replication features derived from a cryptic plasmid of C. Fetus subsp. venerealis strain 4111/108, designated pCFV108, were adapted for a compatible series of constructions. The substitution of the C. coli replication elements reduced vector size while apparently limiting the host range to C. Fetus. The complementation of a ciprofloxacin-resistant mutant phenotype via vector-driven gyrA expression was verified. Cocultivation demonstrated that shuttle vectors based on the pCFV108 replicon were compatible with pIP1455 replication functions, and the stable maintenance of two plasmids in a C. Fetus subsp. venerealis host over several months was observed. The application of both vector types will facilitate the investigation of the genetics and cellular interactions of the emerging pathogen C. Fetus.
Jaap A. Wagenaar - One of the best experts on this subject based on the ideXlab platform.
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Comparative Genomics of Campylobacter Fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages
Genome biology and evolution, 2016Co-Authors: Maarten J. Gilbert, William G. Miller, Emma Yee, Aldert Zomer, Linda Van Der Graaf-van Bloois, Collette Fitzgerald, Ken J. Forbes, Guillaume Méric, Samuel K. Sheppard, Jaap A. WagenaarAbstract:Campylobacter Fetus currently comprises three recognized subspecies, which display distinct host association. Campylobacter Fetus subsp. Fetus and C Fetus subsp. venerealis are both associated with endothermic mammals, primarily ruminants, whereas C Fetus subsp. testudinum is primarily associated with ectothermic reptiles. Both C. Fetus subsp. testudinum and C. Fetus subsp. Fetus have been associated with severe infections, often with a systemic component, in immunocompromised humans. To study the genetic factors associated with the distinct host dichotomy in C. Fetus, whole-genome sequencing and comparison of mammal- and reptile-associated C Fetus was performed. The genomes of C Fetus subsp. testudinum isolated from either reptiles or humans were compared with elucidate the genetic factors associated with pathogenicity in humans. Genomic comparisons showed conservation of gene content and organization among C Fetus subspecies, but a clear distinction between mammal- and reptile-associated C Fetus was observed. Several genomic regions appeared to be subspecies specific, including a putative tricarballylate catabolism pathway, exclusively present in C Fetus subsp. testudinum strains. Within C Fetus subsp. testudinum, sapA, sapB, and sapAB type strains were observed. The recombinant locus iamABC (mlaFED) was exclusively associated with invasive C Fetus subsp. testudinum strains isolated from humans. A phylogenetic reconstruction was consistent with divergent evolution in host-associated strains and the existence of a barrier to lateral gene transfer between mammal- and reptile-associated C Fetus Overall, this study shows that reptile-associated C Fetus subsp. testudinum is genetically divergent from mammal-associated C Fetus subspecies.
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campylobacter Fetus infections in humans exposure and disease
Clinical Infectious Diseases, 2014Co-Authors: Jaap A. Wagenaar, Martin J. Blaser, Robert V. Tauxe, Marcel A P Van Bergen, D G Newell, Jos P M Van PuttenAbstract:Campylobacter Fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided insight into sources. Source attribution of sporadic cases through case-control interviews has not been reported. The reservoirs for C. Fetus are mainly cattle and sheep. Products from these animals are suspected as sources for human infections. Campylobacter Fetus is rarely isolated from food, albeit selective isolation methods used in food microbiology are not suited for its detection. We hypothesize that the general population is regularly exposed to C. Fetus through foods of animal origin, cross-contaminated foodstuffs, and perhaps other, as yet unidentified, routes. Campylobacter Fetus infection should be suspected particularly in patients with nonspecific febrile illness who are immunocompromised or who may have been occupationally exposed to ruminants.
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Fetus
2014Co-Authors: Mary E. Patrick, Maarten J. Gilbert, Jaap A. Wagenaar, Martin J. Blaser, Robert V. Tauxe, Collette FitzgeraldAbstract:a newly proposed subspecies of C. Fetus with markers of reptile origin. We summarize epidemiologic information for 9 humans infected with this bacterium. All cases were in men, most of whom were of Asian origin. Infection might have been related to exposure to Asian foods or reptiles. Campylobacter spp. are the most common cause of bacterial gastrointestinal illness in humans. C. jejuni is the most common species and accounts for>88 % of reported cases in the United States (1). C. Fetus is an uncommonly reported species that typically affects immunocompromised, pregnant, or elderly persons and causes severe infections, including bacteremia and meningitis (2). Two subspecies of C. Fetus have been described: C. Fetus subsp. Fetus and C. Fetus subsp. venerealis (3). C. Fetus subsp. Fetus has been isolated from intestinal tracts of sheep and cattle and from tissues from sporadic abortions in these species. C. Fetus subsp. venerealis is restricted to cattle and causes bovine genital campylobacteriosis (4). Although C. Fetus subsp. venerealis has been isolated from humans (5), its role in human disease is uncertain; most cases of C. Fetus infection are caused by C. Fetus subsp. Fetus. In 1984, C. Fetus was isolated from feces of a reptile, a Florida box turtle (Terrapene carolina bauri) that was kept as a pet (6). C. Fetus has also been isolated from feces of a healthy western hognose snake (Heterodon nasicus) and a blotched blue-tongue lizard (Tiliqua nigrolutea) tha
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evaluation of molecular assays for identification campylobacter Fetus species and subspecies and development of a c Fetus specific real time pcr assay
Journal of Microbiological Methods, 2013Co-Authors: L Van Bloois, M A P Van Bergen, A G De Boer, Birgitta Duim, T Schmidt, Jaap A. WagenaarAbstract:article i nfo Phenotypicdifferentiation between Campylobacter Fetus (C. Fetus)subspeciesFetus and C. Fetussubspecies venerealis is hampered by poor reliability and reproducibility of biochemical assays. AFLP (amplified fragment length poly- morphism) and MLST (multilocus sequence typing) are the molecular standards for C. Fetus subspecies identifica- tion, but these methods are laborious and expensive. Several PCR assays for C. Fetus subspecies identification have been described, but a reliable comparison of these assays is lacking. The aim of this study was to evaluate the most practical and routinely implementable published PCR assays designed for C. Fetus species and subspecies identification. The sensitivity and specifi city of the assays were calcu- lated by using an extensively characterized and diverse collection of C. Fetus strains. AFLP and MLST identification were used as reference. Two PCR assays were able to identify C. Fetus strains correctly at species level. The C. Fetus speciesidentification target, gene nahE, of one PCR assay was used to develop a real-timePCR assay with 100% sen- sitivity and 100% specificity, but the development of a subspecies venerealis specific real-time PCR (ISCfe1) failed due to sequence variation of the target insertion sequence and prevalence in otherCampylobacter species. None of the published PCR assays was able to identify C. Fetus strains correctly at subspecies level. Molecular analysis by AFLP or MLST is still recommended to identify C. Fetus isolates at subspecies level.
Gregor Gorkiewicz - One of the best experts on this subject based on the ideXlab platform.
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a genomic island defines subspecies specific virulence features of the host adapted pathogen campylobacter Fetus subsp venerealis
Journal of Bacteriology, 2010Co-Authors: Gregor Gorkiewicz, Sabine Kienesberger, Caroline Schober, Sylvia R Scheicher, Christian Gully, Rudolf Zechner, Ellen L ZechnerAbstract:The pathogen Campylobacter Fetus comprises two subspecies, C. Fetus subsp. Fetus and C. Fetus subsp. venerealis. Although these taxa are highly related on the genome level, they are adapted to distinct hosts and tissues. C. Fetus subsp. Fetus infects a diversity of hosts, including humans, and colonizes the gastrointestinal tract. In contrast, C. Fetus subsp. venerealis is largely restricted to the bovine genital tract, causing epidemic abortion in these animals. In light of their close genetic relatedness, the specific niche preferences make the C. Fetus subspecies an ideal model system to investigate the molecular basis of host adaptation. In this study, a subtractive-hybridization approach was applied to the genomes of the subspecies to identify different genes potentially underlying this specificity. The comparison revealed a genomic island uniquely present in C. Fetus subsp. venerealis that harbors several genes indicative of horizontal transfer and that encodes the core components necessary for bacterial type IV secretion. Macromolecular transporters of this type deliver effector molecules to host cells, thereby contributing to virulence in various pathogens. Mutational inactivation of the putative secretion system confirmed its involvement in the pathogenicity of C. Fetus subsp. venerealis.
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development of experimental genetic tools for campylobacter Fetus
Applied and Environmental Microbiology, 2007Co-Authors: Sabine Kienesberger, Gregor Gorkiewicz, Sylvia R Scheicher, Martina M Joainig, Eva Leitner, Ellen L ZechnerAbstract:Molecular analysis of the virulence mechanisms of the emerging pathogen Campylobacter Fetus has been hampered by the lack of genetic tools. We report the development and functional analysis of Escherichia coli-Campylobacter shuttle vectors that are appropriate for C. Fetus. Some vectors were constructed based on the known Campylobacter coli plasmid pIP1455 replicon, which confers a wide host range in Campylobacter spp. Versatility in directing gene expression was achieved by introducing a strong C. Fetus promoter. The constructions carry features necessary and sufficient to detect the expression of phenotypic markers, including molecular reporter genes in both subspecies of C. Fetus, while retaining function in C. jejuni. The capacity to express several gene products from different vectors in a single host can be advantageous but requires distinct plasmid replicons. To this end, replication features derived from a cryptic plasmid of C. Fetus subsp. venerealis strain 4111/108, designated pCFV108, were adapted for a compatible series of constructions. The substitution of the C. coli replication elements reduced vector size while apparently limiting the host range to C. Fetus. The complementation of a ciprofloxacin-resistant mutant phenotype via vector-driven gyrA expression was verified. Cocultivation demonstrated that shuttle vectors based on the pCFV108 replicon were compatible with pIP1455 replication functions, and the stable maintenance of two plasmids in a C. Fetus subsp. venerealis host over several months was observed. The application of both vector types will facilitate the investigation of the genetics and cellular interactions of the emerging pathogen C. Fetus.
Ellen L Zechner - One of the best experts on this subject based on the ideXlab platform.
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a genomic island defines subspecies specific virulence features of the host adapted pathogen campylobacter Fetus subsp venerealis
Journal of Bacteriology, 2010Co-Authors: Gregor Gorkiewicz, Sabine Kienesberger, Caroline Schober, Sylvia R Scheicher, Christian Gully, Rudolf Zechner, Ellen L ZechnerAbstract:The pathogen Campylobacter Fetus comprises two subspecies, C. Fetus subsp. Fetus and C. Fetus subsp. venerealis. Although these taxa are highly related on the genome level, they are adapted to distinct hosts and tissues. C. Fetus subsp. Fetus infects a diversity of hosts, including humans, and colonizes the gastrointestinal tract. In contrast, C. Fetus subsp. venerealis is largely restricted to the bovine genital tract, causing epidemic abortion in these animals. In light of their close genetic relatedness, the specific niche preferences make the C. Fetus subspecies an ideal model system to investigate the molecular basis of host adaptation. In this study, a subtractive-hybridization approach was applied to the genomes of the subspecies to identify different genes potentially underlying this specificity. The comparison revealed a genomic island uniquely present in C. Fetus subsp. venerealis that harbors several genes indicative of horizontal transfer and that encodes the core components necessary for bacterial type IV secretion. Macromolecular transporters of this type deliver effector molecules to host cells, thereby contributing to virulence in various pathogens. Mutational inactivation of the putative secretion system confirmed its involvement in the pathogenicity of C. Fetus subsp. venerealis.
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development of experimental genetic tools for campylobacter Fetus
Applied and Environmental Microbiology, 2007Co-Authors: Sabine Kienesberger, Gregor Gorkiewicz, Sylvia R Scheicher, Martina M Joainig, Eva Leitner, Ellen L ZechnerAbstract:Molecular analysis of the virulence mechanisms of the emerging pathogen Campylobacter Fetus has been hampered by the lack of genetic tools. We report the development and functional analysis of Escherichia coli-Campylobacter shuttle vectors that are appropriate for C. Fetus. Some vectors were constructed based on the known Campylobacter coli plasmid pIP1455 replicon, which confers a wide host range in Campylobacter spp. Versatility in directing gene expression was achieved by introducing a strong C. Fetus promoter. The constructions carry features necessary and sufficient to detect the expression of phenotypic markers, including molecular reporter genes in both subspecies of C. Fetus, while retaining function in C. jejuni. The capacity to express several gene products from different vectors in a single host can be advantageous but requires distinct plasmid replicons. To this end, replication features derived from a cryptic plasmid of C. Fetus subsp. venerealis strain 4111/108, designated pCFV108, were adapted for a compatible series of constructions. The substitution of the C. coli replication elements reduced vector size while apparently limiting the host range to C. Fetus. The complementation of a ciprofloxacin-resistant mutant phenotype via vector-driven gyrA expression was verified. Cocultivation demonstrated that shuttle vectors based on the pCFV108 replicon were compatible with pIP1455 replication functions, and the stable maintenance of two plasmids in a C. Fetus subsp. venerealis host over several months was observed. The application of both vector types will facilitate the investigation of the genetics and cellular interactions of the emerging pathogen C. Fetus.
Martin J. Blaser - One of the best experts on this subject based on the ideXlab platform.
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campylobacter Fetus infections in humans exposure and disease
Clinical Infectious Diseases, 2014Co-Authors: Jaap A. Wagenaar, Martin J. Blaser, Robert V. Tauxe, Marcel A P Van Bergen, D G Newell, Jos P M Van PuttenAbstract:Campylobacter Fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided insight into sources. Source attribution of sporadic cases through case-control interviews has not been reported. The reservoirs for C. Fetus are mainly cattle and sheep. Products from these animals are suspected as sources for human infections. Campylobacter Fetus is rarely isolated from food, albeit selective isolation methods used in food microbiology are not suited for its detection. We hypothesize that the general population is regularly exposed to C. Fetus through foods of animal origin, cross-contaminated foodstuffs, and perhaps other, as yet unidentified, routes. Campylobacter Fetus infection should be suspected particularly in patients with nonspecific febrile illness who are immunocompromised or who may have been occupationally exposed to ruminants.
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Fetus
2014Co-Authors: Mary E. Patrick, Maarten J. Gilbert, Jaap A. Wagenaar, Martin J. Blaser, Robert V. Tauxe, Collette FitzgeraldAbstract:a newly proposed subspecies of C. Fetus with markers of reptile origin. We summarize epidemiologic information for 9 humans infected with this bacterium. All cases were in men, most of whom were of Asian origin. Infection might have been related to exposure to Asian foods or reptiles. Campylobacter spp. are the most common cause of bacterial gastrointestinal illness in humans. C. jejuni is the most common species and accounts for>88 % of reported cases in the United States (1). C. Fetus is an uncommonly reported species that typically affects immunocompromised, pregnant, or elderly persons and causes severe infections, including bacteremia and meningitis (2). Two subspecies of C. Fetus have been described: C. Fetus subsp. Fetus and C. Fetus subsp. venerealis (3). C. Fetus subsp. Fetus has been isolated from intestinal tracts of sheep and cattle and from tissues from sporadic abortions in these species. C. Fetus subsp. venerealis is restricted to cattle and causes bovine genital campylobacteriosis (4). Although C. Fetus subsp. venerealis has been isolated from humans (5), its role in human disease is uncertain; most cases of C. Fetus infection are caused by C. Fetus subsp. Fetus. In 1984, C. Fetus was isolated from feces of a reptile, a Florida box turtle (Terrapene carolina bauri) that was kept as a pet (6). C. Fetus has also been isolated from feces of a healthy western hognose snake (Heterodon nasicus) and a blotched blue-tongue lizard (Tiliqua nigrolutea) tha
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comparative genome analysis of campylobacter Fetus subspecies revealed horizontally acquired genetic elements important for virulence and niche specificity
PLOS ONE, 2014Co-Authors: Sabine Kienesberger, Hanna Sprenger, Stella Wolfgruber, Bettina Halwachs, Gerhard G Thallinger, Guillermo I Perezperez, Martin J. BlaserAbstract:Campylobacter Fetus are important animal and human pathogens and the two major subspecies differ strikingly in pathogenicity. C. Fetus subsp. venerealis is highly niche-adapted, mainly infecting the genital tract of cattle. C. Fetus subsp. Fetus has a wider host-range, colonizing the genital- and intestinal-tract of animals and humans. We report the complete genomic sequence of C. Fetus subsp. venerealis 84-112 and comparisons to the genome of C. Fetus subsp. Fetus 82-40. Functional analysis of genes predicted to be involved in C. Fetus virulence was performed. The two subspecies are highly syntenic with 92% sequence identity but C. Fetus subsp. venerealis has a larger genome and an extra-chromosomal element. Aside from apparent gene transfer agents and hypothetical proteins, the unique genes in both subspecies comprise two known functional groups: lipopolysaccharide production, and type IV secretion machineries. Analyses of lipopolysaccharide-biosynthesis genes in C. Fetus isolates showed linkage to particular pathotypes, and mutational inactivation demonstrated their roles in regulating virulence and host range. The comparative analysis presented here broadens knowledge of the genomic basis of C. Fetus pathogenesis and host specificity. It further highlights the importance of surface-exposed structures to C. Fetus pathogenicity and demonstrates how evolutionary forces optimize the fitness and host-adaptation of these pathogens.