Twenty Gram-negative, rod-shaped, slightly curved, non-spore-forming bacteria that gave a negative result in Arcobacter species-specific PCR tests but that yielded an amplicon in an Arcobacter genus-specific PCR test were isolated from 13 unrelated broiler carcasses. Numerical analysis of the profiles obtained by SDS-PAGE of whole-cell proteins clustered all isolates in a single group distinct from the other Arcobacter species. DNA–DNA hybridization among four representative strains exhibited DNA binding values above 91 %. DNA–DNA hybridization with reference strains of the current four Arcobacter species revealed binding levels below 47 %. The G+C contents ranged between 26·8 and 27·3 mol%. Pairwise comparison of 16S rRNA gene sequences revealed the mean values for similarity to the type strain of Arcobacter cryaerophilus (97·5 %), Arcobacter butzleri (96·5 %), Arcobacter skirrowii (96·0 %) and Arcobacter nitrofigilis (95·0 %). The levels of similarity to Campylobacter and Helicobacter species were below 88 and 87 %, respectively. The isolates could be distinguished from other Arcobacter species by the following biochemical tests: catalase, oxidase and urease activities; reduction of nitrate; growth at 25 and 37 °C under aerobic conditions; growth on 2–4 % (w/v) NaCl media; and susceptibility to cephalothin. These data demonstrate that the 20 isolates represent a single novel Arcobacter species, for which the name Arcobacter cibarius sp. nov. is proposed, with LMG 21996^T (=CCUG 48482^T) as the type strain.

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.

Successively slaughtered poultry flocks were sampled for Salmonella to study the relationship between gastrointestinal colonization of the birds and contamination of the carcasses after slaughter. ...

Five repetitive-element PCR (rep-PCR) techniques [primer sets ERIC1R-ERIC2 and REP1R-REP2I and primers ERIC2, BOXA1R, and (GTG) ₅ ] were evaluated for the discrimination of Salmonella enterica isolates at the serotype level. On the basis of number, even distribution over the whole fingerprint, and clarity of bands in the fingerprints, the enterobacterial repetitive intergenic consensus (ERIC) primer set and the (GTG) ₅ primer were chosen for use in the following experiments. For these two primer sets, reproducibility was tested on different lysates of five selected serotypes of Salmonella in the same PCR by using three different PCR runs. Reproducibility was poor between different PCR runs but high within the same PCR run. Furthermore, 80 different serotypes and five isolates which were not typeable by serotyping were fingerprinted. All strains were typeable by the ERIC primer set and the (GTG) ₅ primer and generated unique fingerprints, except for some strains with incomplete antigenic codes. Finally, 55 genetically different strains belonging to 10 serotypes were fingerprinted to examine the genetic diversity of the rep-PCR within serotypes. This experiment showed that one serotype did not always correlate to only one ERIC or (GTG) ₅ fingerprint but that the fingerprint heterogeneity within a serotype was limited. In epidemiological studies, ERIC- and/or (GTG) ₅ -PCR can be used to limit the number of strains that have to be serotyped. The reproducibility of isolates in one PCR run, the discriminatory power, and the genetic diversity (stability) of the fingerprint were similar for the Eric primer set and the (GTG) ₅ primer, so both are equally able to discriminate Salmonella serotypes.

Extreme habitats are not only limited to natural environments, but also exist in manmade systems, for instance, household appliances such as dishwashers. Limiting factors, such as high temperatures, high and low pHs, high NaCl concentrations, presence of detergents, and shear force from water during washing cycles, define microbial survival in this extreme system. Fungal and bacterial diversity in biofilms isolated from rubber seals of 24 different household dishwashers was investigated using next-generation sequencing. Bacterial genera such as Pseudomonas , Escherichia , and Acinetobacter , known to include opportunistic pathogens, were represented in most samples. The most frequently encountered fungal genera in these samples belonged to Candida , Cryptococcus , and Rhodotorula , also known to include opportunistic pathogenic representatives. This study showed how specific conditions of the dishwashers impact the abundance of microbial groups and investigated the interkingdom and intrakingdom interactions that shape these biofilms. The age, usage frequency, and hardness of incoming tap water of dishwashers had significant impact on bacterial and fungal community compositions. Representatives of Candida spp. were found at the highest prevalence (100%) in all dishwashers and are assumed to be one of the first colonizers in recently purchased dishwashers. Pairwise correlations in tested microbiomes showed that certain bacterial groups cooccur, as did the fungal groups. In mixed bacterial-fungal biofilms, early adhesion, contact, and interactions were vital in the process of biofilm formation, where mixed complexes of bacteria and fungi could provide a preliminary biogenic structure for the establishment of these biofilms. IMPORTANCE Worldwide demand for household appliances, such as dishwashers and washing machines, is increasing, as is the number of immunocompromised individuals. The harsh conditions in household dishwashers should prevent the growth of most microorganisms. However, our research shows that persisting polyextremotolerant groups of microorganisms in household appliances are well established under these unfavorable conditions and supported by the biofilm mode of growth. The significance of our research is in identifying the microbial composition of biofilms formed on dishwasher rubber seals, how diverse abiotic conditions affect microbiota, and which key microbial members were represented in early colonization and contamination of dishwashers, as these appliances can present a source of domestic cross-contamination that leads to broader medical impacts.