Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2020
Publication Date: 2/20/2020
Citation: Ghatak, S., He, Y., Reed, S.A., Irwin, P.L. 2020. Comparative analysis of genomic and functional characteristics of a multidrug resistant Campylobacter jejuni strain YH002 isolated from retail beef liver. Foodborne Pathogens and Disease. https://doi.org/10.1089/fpd.2019.2770.
Interpretive Summary: Campylobacter is one of the most common causes of bacterial foodborne illness in the United States. Within the genus Campylobacter there are 29 species, C. jejuni causes most of the human illness. This pathogen is commonly found in food, particularly in meat products. In this work, we isolated a unique C. jejuni strain from beef liver and sequenced the whole genome using high-throughput sequencing technologies. Genomic analysis revealed the abundance of virulence and antibiotic resistance genes, indicating a high potential for this organism to cause disease. Predictions based on analysis of the genome sequence were highly correlated with virulence properties of the strain, in particular those related to motility and antibiotic resistance. Further investigation of the genome revealed a novel toxin/antitoxin system not previously reported in Campylobacter. The results of this study provide new insight into this organism's antibiotic resistance and virulence potential.
Technical Abstract: Campylobacter jejuni is a major cause of bacterial gastroenteritis worldwide. In this study, we report the comparative genomic and functional characteristics of C. jejuni YH002 isolated from retail beef liver. Whole genome sequencing (WGS) of the strain revealed a 1,820,488 bp genome comprised of a chromosome (1,774,584 bp, GenBank accession numbers CP020775) and a plasmid (45,904 bp, CP020776). Annotation of the genome predicted novel features including an integrated intact phage element, multiple antimicrobial resistance (AMR) genes, virulence factors, and a Phd-Doc type toxin-antitoxin (TA) system. Phenotypic tests of AMR showed that C. jejuni YH002 was resistant to amoxicillin and tetracycline, which correlates with the AMR genes found in the strain. Comparative analysis of cell motility at genotypic and phenotypic levels identified discernible patterns of amino acids changes, could explain the variations of motility among C. jejuni strains. Together these results provide important clues to the genetic mechanisms of antimicrobial resistance and cell motility in C. jejuni. The finding of a phd-doc TA system in the genome of C. jejuni YH002 is the first report of this TA system in Campylobacter.