Genome sequencing and analysis of an atypical aerotolerant strain of the foodborne pathogen Campylobacter jejuni. Genome of Campylobacter jejuni Bf

Campylobacter is a Gram-negative bacterium, spiral-shaped and motile. This microorganism lives as commensal organisms in of the gastrointestinal tract of most warm-blooded animals, especially poultry. Campylobacter is the most commonly reported gastrointestinal bacterial pathogen in humans in the European Union (EFSA, 2015). In 2013, the incidence of this zoonosis is of 64.8 per 100,000 population exceeding the number of salmonellosis. 80.6% of confirmed cases of campylobacteriosis were reported to be due to C. jejuni, 7.1 % C. coli, 0.22 % C. lari, and 0.08 % C. upsaliensis. Human infection is commonly associated to cross-contamination of products with contaminated poultry meat. The clinical manifestation of Campylobacter is a sever gastro enteritis called campylobacteriosis. Post-infectious illness could also occur leading to immunoreactive complications such as Guillain-Barré Syndrome and Miller Fisher Syndrome, a chronic and potentially fatal form of paralysis (WHO, 2013). Since 2005, In EU, the cost of campylobacteriosis to public health systems and the loss of individual health and productivity estimated to be around 2.4 billion € per year (EFSA, 2014) and between 1.2 and 4 billion $ for the US (Eberle, 2012 ; Batz, 2014). Despite its specifics growth characteristics (microaerophilic, thermotolerant, capnophilic bacteria), C. jejuni is able to persist to different environmental stresses conditions explaining its high prevalence around the world. This suggests that the food-borne pathogen have developed some many adaptation mechanisms to survive under hard environmental conditions, from poultry to the consumer's plate through the slaughterhouse. One of the most important thinks for this microaerophilic bacterium is to survive in aerobic environments, suggesting protective mechanisms against oxidative stress created by environmental oxygen tension and reactive oxygen species. Surprisingly, we isolated form a French patient who suffered from a severe campylobacteriosis a strain able to growth under aerobic condition. This strain, called C. jejuni Bf, seems to be the only one among C. jejuni strains available (Rodriguez et al., 2015, submitted). Due to this atypical phenotype, de novo sequencing was conducted by GATC an Illumina HiSeq 2000 and an assembly Velvet has been achieved. For the annotation of this strain we have worked Génoscope - French national sequencing center in Paris (CNS, CEA, Evry, France). Finishing and expert annotation are performed using the MicroScope platform of the Génoscope. The main objectives of our work are (i) to performe genomic comparison of C. jejuni Bf genome with other C. jejuni strains genomes in order to highlight the genomic particularities of our strain; (ii) to conduct transcriptomic (RNA-seq) and ChIP-Seq studies to identify the role of some target regulators in the biology of this strain.