Abstract
Campylobacter infections are the leading cause of bacterial gastroenteritis. In Europe, over 246,000 cases are confirmed annually. Infections are often transmitted via contaminated food, such as poultry products, but water may be the source of infection as well. The aim of this study was to characterise a selection of Campylobacter jejuni human isolates, together with a water isolate, from a waterborne outbreak in Norway in 2019, including human isolates from early, mid-, and late epidemic. The isolates were characterised with whole-genome sequencing, analysing the expression of putative virulence genes and demonstrating the pathogenic potential in an in vitro adhesion model using HT-29 cells. All isolates belonged to the multilocus sequence type 1701 and ST45 clonal complex. In the genomic analysis, the water isolate clustered somewhat separately from the human isolates. There was some variation between the human isolates, but the water isolate seemed to display the greatest pathogenic potential, demonstrated by the highest levels of virulence gene expression, adhesion to epithelial cells and IL-8 induction. These results suggest that the water isolate of the study has potential to cause human infections, and that some bacterial changes due to host or environmental adaptation, may occur during a waterborne Campylobacter epidemic. This is, to the best of our knowledge, the first study on C. jejuni isolates from a waterborne outbreak, including both human isolates and a water isolate, characterised with genomic and phenotypic approaches.
Highlights
According to the World Health Organization (WHO), foodborne illness poses a global public health challenge, as each year 600 million cases of illness is caused by consuming unsafe food or water (World Health Organization, 2015)
This study characterised human isolates and a water isolate from a waterborne outbreak of C. jejuni, which occurred in Askøy, an island northwest of Bergen, Norway during the summer of 2019
There are currently more than 10,000 sequence types (STs) that have been typed according to the multilocus sequence typing (MLST) system
Summary
According to the World Health Organization (WHO), foodborne illness poses a global public health challenge, as each year 600 million cases of illness is caused by consuming unsafe food or water (World Health Organization, 2015). Campylobacter spp., which cause campylobacteriosis, a diarrhoeal disease in humans, is the most frequently reported foodborne illness in the European Union (EU) creating a financial burden of approximately 2.4 billion euro annually [European Food. C. jejuni (80%–90%) and C. coli (5%–10%) are the two predominant species causing gastrointestinal infections in humans (Blaser, 1997). The most likely source for Campylobacter infections is poultry (Skarp et al, 2016), but due to their broad natural reservoir, Campylobacter spp. can be transmitted via water. Campylobacteriosis is characterised by symptoms including high fever, headache, nausea, and diarrhoea, which can sometimes be bloody (Blaser, 1997)
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.
