Abstract
Arcobacter species are highly abundant in sewage where they often comprise approximately 5–11% of the bacterial community. Oligotyping of sequences amplified from the V4V5 region of the 16S rRNA gene revealed Arcobacter populations from different cities were similar and dominated by 1–3 members, with extremely high microdiversity in the minor members. Overall, nine subgroups within the Arcobacter genus accounted for >80% of the total Arcobacter sequences in all samples analyzed. The distribution of oligotypes varied by both sample site and temperature, with samples from the same site generally being more similar to each other than other sites. Seven oligotypes matched with 100% identity to characterized Arcobacter species, but the remaining 19 abundant oligotypes appear to be unknown species. Sequences representing the two most abundant oligotypes matched exactly to the reference strains for A. cryaerophilus group 1B (CCUG 17802) and group 1A (CCUG 17801T), respectively. Oligotype 1 showed generally lower relative abundance in colder samples and higher relative abundance in warmer samples; the converse was true for Oligotype 2. Ten other oligotypes had significant positive or negative correlations between temperature and proportion in samples as well. The oligotype that corresponded to A. butzleri, the Arcobacter species most commonly isolated by culturing in sewage studies, was only the eleventh most abundant oligotype. This work suggests that Arcobacter populations within sewer infrastructure are modulated by temperature. Furthermore, current culturing methods used for identification of Arcobacter fail to identify some abundant members of the community and may underestimate the presence of species with affinities for growth at lower temperatures. Understanding the ecological factors that affect the survival and growth of Arcobacter spp. in sewer infrastructure may better inform the risks associated with these emerging pathogens.
Highlights
The genus Arcobacter, described by Vandamme et al (1992), belongs to the family Campylobacteraceae within the epsilonProteobacteria
SAMPLE ENVIRONMENTAL FACTORS AND DISTRIBUTION OF OLIGOTYPES AMONG SAMPLES The percentage of the total bacterial community that mapped to the genus Arcobacter ranged between 0.8 and 19.6% for most samples, and 27/37 samples had more than 5% Arcobacter
Alignments of the nearly complete (>1400 bp) 16S rRNA gene of Arcobacter reference strains (Figure S1) allowed the calculation of the Shannon entropy within the V4V5 region compared to the other variable regions; entropy within the V4V5 amplicon sequences is shown as well
Summary
The genus Arcobacter, described by Vandamme et al (1992), belongs to the family Campylobacteraceae within the epsilonProteobacteria. The genus Arcobacter currently contains 18 species (Levican et al, 2013a; Sasi Jyothsna et al, 2013) isolated from diverse environments (water, plant roots, food) and hosts (humans, poultry, pigs, shellfish) (Collado and Figueras, 2011). Three Arcobacter species, A. butzleri, A. cryaerophilus, and A. skirrowii, have emerged in recent years as potential human pathogens (Collado and Figueras, 2011). The development of new DNA-based screening methods for clinical samples shows that arcobacters can often be mistaken for Campylobacter spp., and the potential human pathogenicity of these microbes is likely underestimated as is their role in water- and food-borne disease (Collado and Figueras, 2011; Figueras et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
