Investigation of arcobacters in meat and faecal samples of clinically healthy cattle in Turkey

AIMS: To investigate the presence of Arcobacter spp. in minced beef meat (n = 97) and rectal faecal samples (n = 200) collected from cattle immediately after slaughter at a local abattoir in Turkey. METHODS AND RESULTS: Meat samples were examined using three different isolation procedures (CAT-supplemented media, de Boer arcobacter isolation method and membrane filtration method), but only one method (CAT-supplemented media) was employed for faecal samples. The isolated Arcobacter strains were identified by genus- and species-(multiplex) specific PCR assays. Arcobacter spp. were isolated from 5 and 9.5% of meat and faecal samples respectively. Although the only Arcobacter sp. found in meat samples was Arcobacter butzleri, all three pathogenic species--A. butzleri, A. cryaerophilus and A. skirrowii--were detected in the rectal swabs. No Arcobacter was isolated when the de Boer method was used for minced meat samples but the same five meat samples were found positive for arcobacters when CAT-supplemented media and membrane filtration method were used. CONCLUSIONS: The membrane filtration method was found to be superior to the CAT-supplemented media, because it led to a reduction in competing microflora. However, the necessity for one filter and medium for each sample makes this method somewhat expensive. The multiplex-PCR (m-PCR) assay shortened significantly the time required for the identification of Arcobacter spp. and also removed the possibility of false positive results due to other campylobacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reports the isolation of Arcobacter spp. in cattle for the first time in Turkey. The m-PCR assay enables the identification and differentiation of all arcobacters simultaneously in one-step PCR.     

Differentiation of Arcobacter species by numerical analysis of AFLP profiles and description of a novel Arcobacter from pig abortions and turkey faeces

AIMS: To evaluate the efficacy of amplified fragment length polymorphism (AFLP)-based genetic profiling for taxonomic and epidemiological analyses of diverse Arcobacter species. METHODS AND RESULTS: Seventy-two isolates of A. butzleri, A. cryaerophilus, A. skirrowii and A. nitrofigilis, and a previously unclassified porcine abortion strain were studied. AFLP profiling was performed using a BglII-Csp6I-based protocol previously used to characterize Campylobacter species. Duplicate profiles of 20 isolates were 93.25% similar, indicating high reproducibility. Numerical analysis of all 72 strains revealed five phenons at the 29% similarity level, four of which represented each of the known species studied. The remaining phenon was further characterized by phenotypic and 16S rDNA sequence analyses, the results of which indicated it to be a novel Arcobacter species. The genetically distinct subgroups of A. cryaerophilus were differentiated at the 39.5% similarity level. For strain typing, 62 distinct types were defined, with evidence of clonal lineages within A. butzleri, A. cryaerophilus and A. skirrowii. CONCLUSIONS: AFLP profiling is an effective means of determining taxonomic and strain relationships for arcobacters. SIGNIFICANCE AND IMPACT OF THE STUDY: First use of AFLP profiling for diverse Arcobacter species; indication of clonality in A. butzleri, A. cryaerophilus and A. skirrowii; potentially novel Arcobacter taxon identified.     

The survival of three strains of Arcobacter butzleri in the presence of lemon, orange and bergamot essential oils and their components in vitro and on food

AIMS: To test the effect of oils and vapours of lemon, sweet orange and bergamot and their components against three Arcobacter butzleri strains. METHODS AND RESULTS: The disc diffusion method was used to screen the oils and vapours against three strains of A. butzleri. In vitro bergamot was the most inhibitory essential oil (EO) and both citral and linalool were effective. On cabbage leaf, the water isolate was the least susceptible to bergamot EO, citral and linalool (1-2 log reduction), with the chicken isolate being the most susceptible (6-8 log reduction). However, the latter appeared not to be susceptible to vapours over 24 h although type strain and water isolate populations reduced by 8 logs. On chicken skin, the effectiveness of the oils was reduced compared with that on cabbage leaf. CONCLUSIONS: Bergamot was the most effective of the oils tested and linalool the most effective component. All strains tested were less susceptible in food systems than in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: Arcobacter isolates vary in their response to EO suggesting that the results of type strain studies should be interpreted with caution. Bergamot EO has the potential for the inhibition of this 'emerging' pathogen.     

Survival capacity in water of Arcobacter species under different temperature conditions

Aims:  To assess the survival capacity in vitro of arcobacters in water at temperatures applied in the food industry.
Methods and Results:  Four strains of each Arcobacter species were inoculated in potable water and water with 1% organic material and stored at 4, 7, 20, 52, 56 and 60°C. Samples were taken at known time points and the numbers of bacteria were determined on Arcobacter -selective medium. All Arcobacter species remained viable for a temperature-dependent period of time, although Arcobacter butzleri displayed a significant longer survival and heat resistance . No significant intraspecies differences were detected, resulting in no definite identification of origin or strain dependency. The survival period for all species was prolonged in the presence of the organic material only for the low temperatures.
Conclusions:  The present study demonstrates that water can act as a reservoir and as a potential source of Arcobacter contamination to humans and animals.
Significance and Impact of the Study:  This study assessed for the first time the survival of all human-related Arcobacter species in water. Particularly A. butzleri showed to be the most robust species with regard to temperature which is interesting as that species is often found in human clinical specimens.     

Shedding of Campylobacter spp. in Finnish cattle on dairy farms

Aims:  The aim of this study was to determine variation of prevalence throughout a year, colonization levels and genotypes of Campylobacter jejuni in Finnish dairy cattle herds.
Methods and Results:  Faecal samples and tank milk samples from three dairy cattle herds were taken five times, and swab samples from drinking troughs once during a 1-year sampling period. The samples were enriched in Bolton broth and subsequently spread on mCCDA. Isolates were then subtyped by pulsed-field gel electrophoresis using SmaI. Campylobacter jejuni was detected in 169 of the 340 faecal samples and in one drinking trough sample. Prevalences between herds and sampling times varied widely. The faecal levels of C. jejuni were mainly low. Between one and four SmaI subtypes were identified from each herd per sampling. Two SmaI subtypes persisted in two of the herds throughout the study.
Conclusions:  Dairy cattle can be a long-term reservoir of C. jejuni subtypes similar to clinical isolates. Differences in the colonization potential among C. jejuni strains as well as in the resistance to campylobacter colonization among animals are possible.
Significance and Impact of the Study:  The study provides data on contamination dynamics, colonization levels and the persistence of C. jejuni in dairy cattle.     

Under the microscope: Arcobacter

This review describes characteristics of the genus Arcobacter. Unlike its close phenotypically related neighbour Campylobacter, Arcobacter is not currently a major public health concern, but is considered as an emerging human pathogen, and is of significance towards animal health. This review focuses on the public health significance, culturing and typing, reservoirs, and antimicrobial studies of Arcobacter. Collectively, increasing knowledge in these areas will help to develop measures, which can be used to control this emerging pathogen.     

The structure of the carbohydrate backbone of the lipooligosaccharide from the halophilic bacterium Arcobacter halophilus

A novel oligosaccharide was isolated and identified from the lipooligosaccharide fraction of the halophilic marine bacterium Arcobacter halophilus. The complete structure was achieved by chemical analysis, 2D NMR spectroscopy, and MALDI mass spectrometry as the following:

α-Glc-(1→7)-α-Hep-(1→5)-α-Kdo4P-(2→6)-β-GlcN4P-(1→6)-α-GlcN1P.     

Immunochemical characterization of a haemagglutinating antigen of Arcobacter spp.

Abstract The Arcobacter haemagglutinin has been identified by Western immunoblot to be an immunogenic protein of about 20 kDa. The haemagglutinating activity is sensitive to proteolytic enzyme digestion and heat treatment of 80 °C and above. The Arcobacter haemagglutinin is possibly a lectin-like molecule binding to erythrocytes via a glycan receptor containing d-galactose as part of its structure.     

Novel uncultured Epsilonproteobacteria dominate a filamentous sulphur mat from the 13 degrees N hydrothermal vent field, East Pacific Rise

Rapid growth of microbial sulphur mats have repeatedly been observed during oceanographic cruises to various deep-sea hydrothermal vent sites. The microorganisms involved in the mat formation have not been phylogenetically characterized, although the production of morphologically similar sulphur filaments by a Arcobacter strain coastal marine has been documented. An in situ collector deployed for 5 days at the 13 degrees N deep-sea hydrothermal vent site on the East Pacific Rise (EPR) was rapidly colonized by a filamentous microbial mat. Microscopic and chemical analyses revealed that the mat consisted of a network of microorganisms embedded in a mucous sulphur-rich matrix. Molecular surveys based on 16S rRNA gene and aclB genes placed all the environmental clone sequences within the Epsilonproteobacteria. Although few 16S rRNA gene sequences were affiliated with that of cultured organisms, the majority was related to uncultured representatives of the Arcobacter group (< or = 95% sequence similarity). A probe designed to target all of the identified lineages hybridized with more than 95% of the mat community. Simultaneous hybridizations with the latter probe and a probe specific to Arcobacter spp. confirmed the numerical dominance of Arcobacter-like bacteria. This study provides the first example of the prevalence and ecological significance of free-living Arcobacter at deep-sea hydrothermal vents.