The genome of C. jejuni RM1221 is a single circular chromosome, 1,777,831 bp in length, with an average G+C content of 30.31%. There are a total of 1,884 predicted coding regions in the genome with an average ORF length of 885 bp. Ninety-four percent of the genome represents coding sequence. Putative role assignments could be made for 1,124 of the ORFs (60%) (Table 1; Figure S1). The bacterium was found to belong to multilocus sequence type (MLST) 354 and FlaA short variable region (SVR) 33, which belongs to clonal complex 354, whose members are associated with human disease or chickens/chicken meat (Table 1) 34. The genome features for the unfinished Campylobacter genomes were based on automated analysis and are presented in Table 1. The average coverage of the unfinished genomes was found to be 8.5-fold for C. coli RM2228, 16.5-fold for C. lari RM2100, and 9.0-fold for C. upsaliensis RM3195 for those contigs used to construct the pseudomolecules. The ambiguity rate (number of consensus-altering ambiguities per basepair) was determined to be between 1:54,000 and 1:93,000 for these unedited, unfinished genomes at 8-fold depth of coverage. The genomic structure of C. jejuni RM1221 is syntenic with the genome of C. jejuni NCTC 11168, and is disrupted by inserted prophages/genomic islands in RM1221 (see below), and ORFs within the capsular (extracellular) polysaccharide (EP) loci in NCTC 11168 (Figures 1A and S2). The C. coli RM2228 genomic structure also has a considerable amount of synteny with C. jejuni RM1221, sharing similar breakpoints, as observed in the C. jejuni comparisons, but displaying evidence of rearrangements about the oriC, as described for other bacterial genomes 35. In contrast, C. lari and C. upsaliensis possess little if any synteny with C. jejuni RM1221.