Butzleri Strains Research Articles

The Immunopathogenic Potential of Arcobacter butzleri - Lessons from a Meta-Analysis of Murine Infection Studies.

BackgroundOnly limited information is available about the immunopathogenic properties of Arcobacter infection in vivo. Therefore, we performed a meta-analysis of published data in murine infection models to compare the pathogenic potential of Arcobacter butzleri with Campylobacter jejuni and commensal Escherichia coli as pathogenic and harmless reference bacteria, respectively.Methodology / Principal FindingsGnotobiotic IL-10-/- mice generated by broad-spectrum antibiotic compounds were perorally infected with A. butzleri (strains CCUG 30485 or C1), C. jejuni (strain 81-176) or a commensal intestinal E. coli strain. Either strain stably colonized the murine intestines upon infection. At day 6 postinfection (p.i.), C. jejuni infected mice only displayed severe clinical sequelae such as wasting bloody diarrhea. Gross disease was accompanied by increased numbers of colonic apoptotic cells and distinct immune cell populations including macrophages and monocytes, T and B cells as well as regulatory T cells upon pathogenic infection. Whereas A. butzleri and E. coli infected mice were clinically unaffected, respective colonic immune cell numbers increased in the former, but not in the latter, and more distinctly upon A. butzleri strain CCUG 30485 as compared to C1 strain infection. Both, A. butzleri and C. jejuni induced increased secretion of pro-inflammatory cytokines such as IFN-γ, TNF, IL-6 and MCP-1 in large, but also small intestines. Remarkably, even though viable bacteria did not translocate from the intestines to extra-intestinal compartments, systemic immune responses were induced in C. jejuni, but also A. butzleri infected mice as indicated by increased respective pro-inflammatory cytokine concentrations in serum samples at day 6 p.i.Conclusion / SignificanceA. butzleri induce less distinct pro-inflammatory sequelae as compared to C. jejuni, but more pronounced local and systemic immune responses than commensal E. coli in a strain-dependent manner. Hence, data point towards that A. butzleri is more than a commensal in vertebrate hosts.

Arcobacter butzleri survives within trophozoite of Acanthamoeba castellanii

The survival of three Arcobacter butzleri strains inside Acanthamoeba castellanii was assessed using axenic cultures of A. castellanii that were inoculated with the tested strains and incubated at 26°C under aerobic conditions for 240h. The behavior of bacteria in contact with amoebae was monitored using phase contrast microscopy. The bacterial survival rate within amoebae was assessed through counting colony forming units, using the gentamicin protection assay. All A. butzleri strains were able to survive during 240h within the amoebae, thus suggesting that (i) A. butzleri resists the amoebic digestion processes at least for the analyzed time; (ii) that A. castellanii could serve as an environmental reservoir for this bacterium, probably acting as a transmission vehicle for A. butzleri.

Toll-Like Receptor-4 Dependent Intestinal Gene Expression During Arcobacter Butzleri Infection of Gnotobiotic Il-10 Deficient Mice.

We have previously shown that Arcobacter butzleri infection induces Toll-like receptor (TLR) -4 dependent immune responses in perorally infected gnotobiotic IL-10–/– mice. Here, we analyzed TLR-4-dependent expression of genes encoding inflammatory mediators and matrix-degrading gelatinases MMP-2 and -9 in the small and large intestines of gnotobiotic TLR-4-deficient IL-10–/– mice that were perorally infected with A. butzleri strains CCUG 30485 or C1, of human and chicken origin, respectively. At day 6 following A. butzleri infection, colonic mucin-2 mRNA, as integral part of the intestinal mucus layer, was downregulated in the colon, but not ileum, of IL-10–/– but not TLR-4–/– IL-10–/– mice. CCUG 30485 strain-infected TLR-4-deficient IL-10–/– mice displayed less distinctly upregulated IFN-γ, IL-17A, and IL-1β mRNA levels in ileum and colon, which was also true for colonic IL-22. These changes were accompanied by upregulated colonic MMP-2 and ileal MMP-9 mRNA exclusively in IL-10–/– mice. In conclusion, TLR-4 is essentially involved in A. butzleri mediated modulation of gene expression in the intestines of gnotobiotic IL-10–/– mice.

Intestinal Expression of Genes Encoding Inflammatory Mediators and Gelatinases During Arcobacter Butzleri Infection of Gnotobiotic Il-10 Deficient Mice.

We have previously shown that Arcobacter butzleri induces intestinal, extra-intestinal, and systemic immune responses in perorally infected gnotobiotic IL-10–/– mice in a strain-dependent fashion. Here, we present a comprehensive survey of small and large intestinal expression profiles of inflammatory and regulatory mediators as well as of the matrix-degrading gelatinases MMP-2 and MMP-9 following murine A. butzleri infection. Gnotobiotic IL-10–/– mice were infected with A. butzleri strains CCUG 30485 or C1 of human and chicken origin, respectively. At day 6 following A. butzleri infection, mucin-2 mRNA, an integral part of the intestinal mucus layer, was downregulated in the colon, whereas TNF and IL-23p19 mRNA were upregulated in the ileum. Furthermore, IFN-γ, IL-17A, IL-1β, and IL-22 mRNA were upregulated in both colonic and ileal ex vivo biopsies at day 6 post strain CCUG 30485 infection. These changes were accompanied by downregulated colonic MMP-9 levels, whereas both MMP-2 and MMP-9 mRNA were upregulated in the ileum. In conclusion, these data indicate that A. butzleri infection induces changes in the expression of genes involved in pro-inflammatory and regulatory immune responses as well as in tissue degradation.

Antimicrobial susceptibility testing of Arcobacter butzleri and Arcobacter cryaerophilus strains isolated from Belgian patients.

To evaluate the feasibility of different methods for susceptibility testing of human Arcobacter isolates, to assess susceptibility to antibiotics commonly used to treat diarrhoeal illness and to obtain MIC distribution data. One-hundred-and-six unique Arcobacter strains were collected during an epidemiological study on pathogens in gastroenteritis. Strains were identified by multiplex PCR and PCR-RFLP, and characterized by PFGE. Susceptibility to ampicillin, erythromycin, tetracycline, doxycycline, gentamicin and ciprofloxacin was determined using gradient strip and disc diffusion methodology. Optimal conditions for growth and incubation were tested. Azithromycin was tested with gradient strip diffusion on a subset of 40 strains. Sequence analysis of the quinolone resistance-determining region of gyrA was performed for a subset of 18 strains. Based on gradient diffusion results, most Arcobacter strains were susceptible to gentamicin (99%) and tetracycline (89%). Erythromycin (78%), ciprofloxacin (72%) and doxycycline (76%) retained moderate activity against Arcobacter spp. Only 9% of the strains were susceptible to ampicillin. Most Arcobacter butzleri strains were susceptible to ciprofloxacin (87%), whereas half of the Arcobacter cryaerophilus isolates (51%) showed high-level resistance (MIC >32 mg/L). MIC50 values were comparable for both macrolide antibiotics. Ciprofloxacin-resistant strains possessed an identical mutation in gyrA. Overall, categorical agreement between gradient and disc diffusion results was 60%. Gradient diffusion showed superior readability. Gradient diffusion methodology is preferred for routine susceptibility testing. Acquired resistance to fluoroquinolones was observed in A. cryaerophilus. Macrolides are not first-choice empirical antibiotics for Arcobacter infections. Tetracyclines can be suggested for treatment of documented Arcobacter-related gastrointestinal infections.

Toll-Like Receptor-4 Dependent Small Intestinal Immune Responses Following Murine Arcobacter Butzleri Infection.

Sporadic cases of gastroenteritis have been attributed to Arcobacter butzleri infection, but information about the underlying immunopathological mechanisms is scarce. We have recently shown that experimental A. butzleri infection induces intestinal, extraintestinal and systemic immune responses in gnotobiotic IL-10–/– mice. The aim of the present study was to investigate the immunopathological role of Toll-like Receptor-4, the receptor for lipopolysaccharide and lipooligosaccharide of Gram-negative bacteria, during murine A. butzleri infection. To address this, gnotobiotic IL-10–/– mice lacking TLR-4 were generated by broad-spectrum antibiotic treatment and perorally infected with two different A. butzleri strains isolated from a patient (CCUG 30485) or fresh chicken meat (C1), respectively. Bacteria of either strain stably colonized the ilea of mice irrespective of their genotype at days 6 and 16 postinfection. As compared to IL-10–/– control animals, TLR-4–/– IL-10–/– mice were protected from A. butzleri-induced ileal apoptosis, from ileal influx of adaptive immune cells including T lymphocytes, regulatory T-cells and B lymphocytes, and from increased ileal IFN-γ secretion. Given that TLR-4-signaling is essential for A. butzleri-induced intestinal inflammation, we conclude that bacterial lipooligosaccharide or lipopolysaccharide compounds aggravate intestinal inflammation and may thus represent major virulence factors of Arcobacter. Future studies need to further unravel the molecular mechanisms of TLR-4-mediated A. butzleri-host interactions.

Survey of small intestinal and systemic immune responses following murine Arcobacter butzleri infection

BackgroundArcobacter (A.) butzleri has been described as causative agent for sporadic cases of human gastroenteritis with abdominal pain and acute or prolonged watery diarrhea. In vitro studies revealed distinct adhesive, invasive and cytotoxic properties of A. butzleri. Information about the underlying immunopathological mechanisms of infection in vivo, however, are scarce. The aim of this study was to investigate the immunopathological properties of two different A.butzleri strains in a well-established murine infection model.ResultsGnotobiotic IL-10−/− mice, in which the intestinal microbiota was depleted by broad-spectrum antibiotic treatment, were perorally infected with two different A. butzleri strains isolated from a diseased patient (CCUG 30485) or fresh chicken meat (C1), respectively. Eventhough bacteria of either strain could stably colonize the intestinal tract at day 6 and day 16 postinfection (p.i.), mice did not exert infection induced symptoms such as diarrhea or wasting. In small intestines of infected mice, however, increased numbers of apoptotic cells could be detected at day 16, but not day 6 following infection with either strain. A strain-dependent influx of distinct immune cell populations such as T and B cells as well as of regulatory T cells could be observed upon A. butzleri infection which was accompanied by increased small intestinal concentrations of pro-inflammatory cytokines such as TNF, IFN-γ, MCP-1 and IL-6. Remarkably, inflammatory responses following A. butzleri infection were not restricted to the intestinal tract, given that the CCUG 30485 strain induced systemic immune responses as indicated by increased IFN-γ concentrations in spleens at day 6, but not day 16 following infection.ConclusionUpon peroral infection A. butzleri stably colonized the intestinal tract of gnotobiotic IL-10−/− mice. The dynamics of distinct local and systemic inflammatory responses could be observed in a strain-dependent fashion pointing towards an immunopathogenic potential of A. butzleri in vivo. These results indicate that gnotobiotic IL-10−/− mice are well suited to further investigate the molecular mechanisms underlying arcobacteriosis in vivo.

Arcobacter butzleri Induce Colonic, Extra-Intestinal and Systemic Inflammatory Responses in Gnotobiotic IL-10 Deficient Mice in a Strain-Dependent Manner.

BackgroundThe immunopathological impact of human Arcobacter (A.) infections is under current debate. Episodes of gastroenteritis with abdominal pain and acute or prolonged watery diarrhea were reported for A. butzleri infected patients. Whereas adhesive, invasive and cytotoxic capacities have been described for A. butzleri in vitro, only limited information is available about the immunopathogenic potential and mechanisms of infection in vivo.Methodology/Principal FindingsGnotobiotic IL-10-/- mice were generated by broad-spectrum antibiotic treatment and perorally infected with the A. butzleri strains CCUG 30485 and C1 shown to be invasive in cell culture assays. Bacterial colonization capacities, clinical conditions, intestinal, extra-intestinal and systemic immune responses were monitored at day six and 16 postinfection (p.i.). Despite stable intestinal A. butzleri colonization at high loads, gnotobiotic IL-10-/- mice were virtually unaffected and did not display any overt symptoms at either time point. Notably, A. butzleri infection induced apoptosis of colonic epithelial cells which was paralleled by increased abundance of proliferating cells. Furthermore A. butzleri infection caused a significant increase of distinct immune cell populations such as T and B cells, regulatory T cells, macrophages and monocytes in the colon which was accompanied by elevated colonic TNF, IFN-γ, nitric oxide (NO), IL-6, IL-12p70 and MCP-1 concentrations. Strikingly, A. butzleri induced extra-intestinal and systemic immune responses as indicated by higher NO concentrations in kidney and increased TNF, IFN-γ, IL-12p70 and IL-6 levels in serum samples of infected as compared to naive mice. Overall, inflammatory responses could be observed earlier in the course of infection by the CCUG 30485 as compared to the C1 strain.Conclusion/SignificancePeroral A. butzleri infection induced not only intestinal but also extra-intestinal and systemic immune responses in gnotobiotic IL-10-/- mice in a strain-dependent manner. These findings point towards an immunopathogenic potential of A. butzleri in vertebrate hosts.

Prevalence of ten putative virulence genes in the emerging foodborne pathogen Arcobacter isolated from food products

Arcobacter spp. are considered to be emerging food- and waterborne pathogens for both humans and animals. However, their virulence mechanisms are still poorly understood. In this study the presence of ten virulence genes (cadF, ciaB, cj1349, hecA, hecB, mviN, pldA, irgA, tlyA and iroE) was assessed in a set of 47 strains of Arcobacter butzleri, 10 of Arcobacter cryaerophilus and 1 Arcobacter skirrowii strain recovered from different food products (pork, chicken, beef, milk, clams and mussels). Overall, the genes cadF, ciaB, cj1349, mviN, pldA and tlyA were detected in all A. butzleri and A. skirrowii strains. Lower detection rates were observed for irgA, iroE, hecA and hecB. The genes hecB and iroE were detected neither in A. cryaerophilus nor in A. skirrowii. The genes hecA and irgA were not detected in A. skirrowii. It was noteworthy that the genes hecA and hecB were significantly (P < 0.05) highly detected in A. butzleri strains isolated from clams compared with strains isolated from milk and chicken. Therefore, our findings underline clams as a source of A. butzleri strains with high prevalence of putative virulence genes. This could be hazardous to human health, especially because these bivalves are usually consumed raw or undercooked.

Development of a comparative genomic fingerprinting assay for rapid and high resolution genotyping of Arcobacter butzleri.

BackgroundMolecular typing methods are critical for epidemiological investigations, facilitating disease outbreak detection and source identification. Study of the epidemiology of the emerging human pathogen Arcobacter butzleri is currently hampered by the lack of a subtyping method that is easily deployable in the context of routine epidemiological surveillance. In this study we describe a comparative genomic fingerprinting (CGF) method for high-resolution and high-throughput subtyping of A. butzleri. Comparative analysis of the genome sequences of eleven A. butzleri strains, including eight strains newly sequenced as part of this project, was employed to identify accessory genes suitable for generating unique genetic fingerprints for high-resolution subtyping based on gene presence or absence within a strain.ResultsA set of eighty-three accessory genes was used to examine the population structure of a dataset comprised of isolates from various sources, including human and non-human animals, sewage, and river water (n=156). A streamlined assay (CGF40) based on a subset of 40 genes was subsequently developed through marker optimization. High levels of profile diversity (121 distinct profiles) were observed among the 156 isolates in the dataset, and a high Simpson’s Index of Diversity (ID) observed (ID > 0.969) indicate that the CGF40 assay possesses high discriminatory power. At the same time, our observation that 115 isolates in this dataset could be assigned to 29 clades with a profile similarity of 90% or greater indicates that the method can be used to identify clades comprised of genetically similar isolates.ConclusionsThe CGF40 assay described herein combines high resolution and repeatability with high throughput for the rapid characterization of A. butzleri strains. This assay will facilitate the study of the population structure and epidemiology of A. butzleri.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-015-0426-4) contains supplementary material, which is available to authorized users.

Arcobacter butzleri induces a pro-inflammatory response in THP-1 derived macrophages and has limited ability for intracellular survival

Recent case reports have identified Arcobacter (A.) butzleri to be another emerging pathogen of the family Campylobacteraceae causing foodborne diseases. However, little is known about its interaction with the human immune system. As macrophages act as first defense against bacterial infections, we studied for the first time the impact of A. butzleri on human macrophages using THP-1 derived macrophages as an in vitro infection model. Our investigations considered the inflammatory response, intracellular survival and activation of caspases as potential virulence mechanisms employed by A. butzleri. Induction of IL-1α, IL-1ß, IL-6, IL-8, IL-12ß and TNFα demonstrated a pro-inflammatory response of infected macrophages towards A. butzleri. gentamycin protection assays revealed the ability of A. butzleri strains to survive and resist the hostile environment of phagocytic immune cells for up to 22h. Moreover, initial activation of intitiator- (CASP8) as well as effector caspases (CASP3/7) was observed without the onset of DNA damage, suggesting a potential counter regulation. Intriguingly, we recognized distinct strain specific differences in invasion and survival capabilities. This suggests the existence of isolate dependent phenotype variations and different virulence potentials as known for other intestinal pathogens such as Salmonella enterica ssp.

Survival of Arcobacter butzleri in Apple and Pear Purees

AbstractThis study examined the survival of Arcobacter butzleri in apple and pear purees. The apple and pear purees were prepared by following a previous study and these were spiked with 6.90–7.44 log10 cfu/g of A. butzleri ATCC49616, A. butzleri CAU076046 and A. butzleri CAU080180, respectively. The number of bacteria, pH value, sugar contents and water activity of apple and pear purees stored at 4 and 20C for 48 h were measured. The population of all strains significantly decreased in apple and pear purees at 8, 12, 24 and 48 h (P &lt; 0.01). Each A. butzleri strain was reduced by 7 log10 cfu/g after 24–48 h in apple or pear purees at 4C. A. butzleri strain CAU080180 was not detected within 12 h and the others were not detected at 20C within 24–48 h. A. butzleri CAU076046 was more resistant in the purees than the other two strains. No significant difference in the pH values, sugar content or water activity was observed between 0 and 48 h. We demonstrated that the number of A. butzleri significantly decreased in apple and pear purees.Practical ApplicationsArcobacter butzleri causes gastroenteritis in children, elderly and immunocompromised patients. The contamination of A. butzleri occurred not only in meats but also in vegetable or fruits. This study demonstrated that A. butzleri was reduced in the apple or pear purees during storage. The combination of pH, organic acids and flavonoids synergistically inhibit the survival of A. butzleri in purees.

Presence of virulence genes, adhesion and invasion ofArcobacter butzleri

The pathogenic potential of Arcobacter butzleri isolates was investigated by detecting the presence of putative virulence genes and analysing the adhesive and invasive capabilities in cell cultures of human cell lines. The presence of ten putative virulence genes in 52 A. butzleri isolates was determined by PCR. The genes ciaB, mviN, pldA, tlyA, cj1349 and cadF were detected in all, whilst irgA (15%), iroE (60%), hecB (44%) and hecA (13%) were detected only in few A. butzleri isolates. On HT-29 cells, four of six isolates adhered to and three of them were able to invade, whilst all six isolates adhered to and invaded Caco-2 cells with higher degrees. The genes ciaB, cadF and cj1349 of all six isolates were sequenced, but no considerable changes of the amino acids in putative functional domains were observed. Selected A. butzleri isolates adhere to and invade HT-29 and Caco-2 cells, which emphasize their human pathogenic potential. The efficiency of invasion depends on the eukaryotic cell line and individual bacterial strain used. We could not show any functional correlation between the amino acid sequence of CadF, CiaB or Cj1349 and the adhesive and invasive phenotype. We have shown that some A. butzleri strains invade various cell lines. This underlines their pathogenic potential and hints at their relevance in human disease.

Fourier Transform Infrared Spectroscopy as a Novel Approach for Analyzing the Biochemical Effects of Anionic Surfactants on a Surfactant-Degrading Arcobacter Butzleri Strain

Anionic surfactant-biodegrading capability of an Arcobacter butzleri strain was analyzed under aerobic conditions. The A. butzleri isolate displayed efficient surfactant-biodegrading capacity for sodium dodecyl sulfate (SDS) at concentrations of up to 100 mg/L in 6 days, corresponding to 99.0% removal efficiency. Fourier transform infrared spectroscopy was applied to observe the effects of varying concentrations of SDS on the biochemistry of bacterial cells. Results suggest that protein secondary structures were altered in bacterial cells at sufficiently high SDS concentrations, concurrent with SDS biodegradation.

Genetic diversity, antibiotic resistance and biofilm-forming ability of Arcobacter butzleri isolated from poultry and environment from a Portuguese slaughterhouse

The genus Arcobacter is an emerging pathogen associated with several clinical symptoms. This genus is widely distributed and has been isolated from environmental, animal, food and human samples, where poultry is considered the major source. In this study, forty three Arcobacter butzleri strains isolated from poultry and environment of a Portuguese slaughterhouse, were characterized by pulsed field gel electrophoresis (PFGE) and assessed for antimicrobial susceptibility and ability to form biofilms. PFGE patterns obtained using restriction enzymes SmaI and SacII revealed high genetic diversity, with 32 distinct PFGE patterns. Most of A. butzleri isolates presented multiple antimicrobial resistance, exhibiting four different resistance profiles. All 43 isolates were susceptible to gentamicin and 2.3% were resistant to chloramphenicol, in contrast to twenty four (55.8%) that were resistant to ciprofloxacin. Among 36 selected isolates, 26 strains presented biofilm-forming ability, which was dependent on the atmosphere and initial inoculum density.Overall, the results showed that A. butzleri displays a high genetic diversity, and presents resistance to several antibiotics, which together with its biofilm formation ability may represent a potential hazard for foodborne infections and a considerable risk for human health.

Enhancing adherence of Arcobacter butzleri after serial intraperitoneal passages in mice

We investigated the possibility of enhancing the adherence capacity of four low-adherent Arcobacter butzleri strains after serial intraperitoneal passage (i.p.) in mice. All the strains enhanced their adherence capacity after the first passage, increasing their adhesion rates after each passage. These results suggest that i.p. passage enhances the expression of adherence in A. butzleri strains.

Antimicrobial susceptibilities of various Arcobacter species

To determine the antimicrobial susceptibilities of various Arcobacter strains isolated from domestic geese, which have great potential for the transmission of arcobacters to humans and animals by contamination of water sources. Materials and methods: A total of 16 Arcobacter strains including A. cryaerophilus (7), A. skirrowii (7), and A. butzleri (2) were examined for their susceptibilities to 20 antibiotics using a disk-diffusion method. Results: All Arcobacter isolates tested were resistant to cloxacillin, cefazolin, optochin, vancomycin, and fusidic acid, and most were susceptible to oxytetracycline, chloramphenicol (except for A. butzleri), nitrofurantoin, amikacin, enrofloxacin, ofloxacin, erythromycin, ampicillin sulbactam, and amoxicillin (except for A. butzleri). All A. skirrowii and most A. cryaerophilus isolates were susceptible to amoxicillin/clavulanic acid. All 3 A. butzleri strains tested were resistant to cephalothin, while most A. skirrowii strains and 3 strains of A. cryaerophilus were susceptible to this antibiotic. Both isolates of A. butzleri were susceptible to rifampicin. Variable results were obtained for the other antibiotics used in this study. Conclusion: The incidence of antibiotic susceptibility in arcobacters varied among species, which suggests that suitable antibiotic(s) should be selected for the treatment of infectious disease(s) and/or when developing selective media for the isolation of a wide range of Arcobacter species.

Growth and survival at chiller temperatures of Arcobacter butzleri

Arcobacter butzleri is prevalent on chicken products. Arcobacter spp. are generally isolated in only low numbers from the chicken gut, so chicken carcasses may be contaminated by A. butzleri that proliferate in the slaughterhouse environment. To address this issue, we examined the behaviour of A. butzleri ATCC 49616 and newly isolated A. butzleri strains under conditions likely to prevail in the slaughterhouse environment using a chicken meat juice medium (CMJ). CMJ supported growth of A. butzleri at 15 °C, the recognised minimal growth temperature of this organism, and at 10 °C. At 5 °C, CMJ enhanced survival of A. butzleri as compared with survival in Brain Heart Infusion with less than a one log reduction after 77 days incubation. Lastly, we examined the ability of A. butzleri to form biofilms and found that the organism produces biofilm at temperatures ranging from 5 to 37 °C. Given the ability to survive, multiply and form biofilm under chilled conditions A. butzleri appears well suited for establishment in food processing and slaughterhouse environments.

Dogs as carriers of the emerging pathogen Arcobacter

Dogs and cats living in a household have previously been identified as a risk factor for human infection with Campylobacter and Helicobacter. In this study, carried out between July 2006 to September 2007, feces and oral swabs from 267 dogs and 61 cats were examined for the presence of the emerging pathogen Arcobacter. Isolates, obtained by an Arcobacter selective isolation procedure, were identified with an Arcobacter species-specific multiplex-PCR and characterized by modified enterobacterial repetitive intergenic concensus PCR. No arcobacters were isolated from cats. Five dogs excreted arcobacters in the feces and two other dogs carried arcobacters in the mouth. In the follow-up, one dog excreted the same Arcobacter butzleri strain for at least 1 week. Six dogs carried each an unique A. cryaerophilus strain although three of them lived in the same family. Therefore, beside the consumption of food and water, contact with dogs is another potential source of Arcobacter infection.

The complete genome sequence and analysis of the epsilonproteobacterium Arcobacter butzleri.

Background Arcobacter butzleri is a member of the epsilon subdivision of the Proteobacteria and a close taxonomic relative of established pathogens, such as Campylobacter jejuni and Helicobacter pylori. Here we present the complete genome sequence of the human clinical isolate, A. butzleri strain RM4018.Methodology/Principal Findings Arcobacter butzleri is a member of the Campylobacteraceae, but the majority of its proteome is most similar to those of Sulfuromonas denitrificans and Wolinella succinogenes, both members of the Helicobacteraceae, and those of the deep-sea vent Epsilonproteobacteria Sulfurovum and Nitratiruptor. In addition, many of the genes and pathways described here, e.g. those involved in signal transduction and sulfur metabolism, have been identified previously within the epsilon subdivision only in S. denitrificans, W. succinogenes, Sulfurovum, and/or Nitratiruptor, or are unique to the subdivision. In addition, the analyses indicated also that a substantial proportion of the A. butzleri genome is devoted to growth and survival under diverse environmental conditions, with a large number of respiration-associated proteins, signal transduction and chemotaxis proteins and proteins involved in DNA repair and adaptation. To investigate the genomic diversity of A. butzleri strains, we constructed an A. butzleri DNA microarray comprising 2238 genes from strain RM4018. Comparative genomic indexing analysis of 12 additional A. butzleri strains identified both the core genes of A. butzleri and intraspecies hypervariable regions, where <70% of the genes were present in at least two strains.Conclusion/SignificanceThe presence of pathways and loci associated often with non-host-associated organisms, as well as genes associated with virulence, suggests that A. butzleri is a free-living, water-borne organism that might be classified rightfully as an emerging pathogen. The genome sequence and analyses presented in this study are an important first step in understanding the physiology and genetics of this organism, which constitutes a bridge between the environment and mammalian hosts.