Interest in arcobacters in veterinary and human public health has increased since the first report of the isolation of arcobacters from food of animal origin. Since then, studies worldwide have reported the occurrence of arcobacters on food and in food production animals and have highlighted possible transmission, especially of Arcobacter butzleri, to the human population. In humans, arcobacters are associated with enteritis and septicemia. To assess their clinical relevance for humans and animals, evaluation of potential virulence factors is required. However, up to now, little has been known about the mechanisms of pathogenicity. Because of their close phylogenetic affiliation to the food-borne pathogen Campylobacter and their similar clinical manifestations, the presence of nine putative Campylobacter virulence genes (cadF, ciaB, cj1349, hecA, hecB, irgA, mviN, pldA, and tlyA) previously identified in the recent Arcobacter butzleri ATCC 49616 genome sequence was determined in a large set of human and animal Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii strains after the development of rapid and accurate PCR assays and confirmed by sequencing and dot blot hybridization.A rcobacters are increasingly being isolated from a wide range of food products all over the world. These Gram-negative bacteria have been classified into the family Campylobacteraceae (35), although a recent annotation of the Arcobacter butzleri genome suggests a closer phylogenetic relation to Sulfurimonas denitrificans and Wolinella succinogenes, both members of the Helicobacteraceae, as well as to the deep-sea vent Epsilonproteobacteria members Sulfurovum and Nitratiruptor (26). At present, 13 Arcobacter species have been characterized, of which 6 were isolated from mammals. In humans, A. butzleri is predominantly associated with enteritis and septicemia (24,30,46), though Arcobacter cryaerophilus and Arcobacter skirrowii have also been isolated from diarrheal stool specimens (21,33,44). The other three species, Arcobacter cibarius (15), Arcobacter thereius (14), and Arcobacter trophiarum (4) are present in farm animals and on food of animal origin but have not yet been isolated from human specimens.Contaminated drinking water is identified as a major source of human Arcobacter infection in developing regions (1), whereas in industrialized countries, infections are assumed to be food-borne. Close contact with pets and person-to-person transmission are the other potential risk factors (9, 36). Arcobacters seem to be commonly present on food of animal origin, with the highest prevalence reported for poultry followed by pork and beef (38,42). The origin of the contamination on poultry products is still debated (39), but for pork and beef, feces transmitted during the slaughter process is regarded as the initial source of contamination (40, 44).The A. butzleri ATCC 49616 genome revealed that this strain has putative virulence determinants such as genes cadF and cj1349, coding for fibronectin binding proteins; the invasi...

No abstract

In the course of a longitudinal study elucidating the dynamics of Arcobacter populations in pigs, 16 isolates of Gram-reaction-negative, rod-shaped, slightly curved, non-spore-forming bacteria were grouped by amplified fragment length polymorphism analysis into a distinct phenon within the genus Arcobacter. Fragments were generated for all isolates in a genus-specific PCR assay, but no amplicon was obtained in a species-specific multiplex-PCR test. Numerical analysis of the whole-cell protein profiles also showed that all isolates clustered in a single group that was distinct from related members of the genus Arcobacter. DNA-DNA hybridizations between two representative strains, designated 64 T and 122, of the isolates obtained exhibited a mean DNA-DNA relatedness of 72 %. DNA-DNA hybridizations between strains 64 T and 122 and reference strains of other animal-related bacteria of the genus Arcobacter revealed binding values of 47 % or less. The DNA G+C contents of the two representative strains were 28.5 and 28.4 mol%, respectively, and analysis of three marker genes identified Arcobacter cryaerophilus, A. thereius, A. cibarius and A. skirrowii as their closest phylogenetic neighbours. Strains 64 T and 122 could be distinguished from other members of the genus Arcobacter by means of biochemical tests for catalase and urease activities, nitrate reduction, indoxyl acetate hydrolysis, lack of growth at 37 6C, growth in 2 % (w/v) NaCl, growth on 0.1 % sodium deoxycholate and non-supplemented Campylobacter charcoal-deoxycholate base medium and resistance to cephalothin (32 mg l "1 ) and cefoperazone (64 mg l "1 ). Additionally, a PCR assay was developed for the detection and identification of strains 64 T and 122, which represent a novel species of the genus Arcobacter, for which the name Arcobacter trophiarum sp. nov. is proposed. The type strain is strain 64 T (5LMG 25534 T 5CCUG 59229 T ).In the late 1970s, Ellis et al. (1977Ellis et al. ( , 1978 reported on the isolation of Campylobacter-like organisms from the internal organs of aborted porcine and bovine fetuses. These bacteria differed from previously described species of the genus Campylobacter in their ability to grow in air and at lower temperatures (Neill et al., 1979;Vandamme et al., 1992b). In 1991, the genus Arcobacter was proposed as a second genus within the family Campylobacteraceae to encompass those bacteria formerly known as aerotolerant campylobacters (Vandamme et al., 1991). At the time of writing, nine species have been described in this genus, four of which are apparently only present in environmental matrices with the remaining five species being human or animal associated.Arcobacter nitrofigilis, A. halophilus, A. mytili, A. marinus and a number of as-yet unclassified organisms, including 'Candidatus Arcobacter sulfidicus', have been isolated from sources such as coastal seawater, shellfish, sea sediment, salt-water lakes, water from underground cavities of oil wells and various kinds of sludge (Collado et al., 2009;Donachie et al., 2005;Ki...

No abstract

No abstract