Comparison of Complete Campylobacter fetus Genomes Derived from Public Repositories

Abstract

Background: Campylobacter fetus(Cf) causes reproductive problems in livestock and infections in immunocompromised individuals. The pathogenesis of Cf can be better understood by using bioinformatics tools to study their genomes. We report on comparative genomic analysis that includes all 23 publicly available complete genomes of C. fetus, as of 30 June 2023, collected from diverse sources across the globe. Results: There was no overlap of ST among the Campylobacter fetussubsp. fetus (Cff), Campylobacter fetus subsp. venerealis(Cfv) and Campylobacter fetus subsp. testudinum (Cft) genomes. The majority (90.0%) of the C. fetus subsp. venerealis (Cfv) were ST-4. Although no phenotypicresistance was predicted, the Bacterial and Viral Bioinformatics Resource Center software identified a total of 635 antibiotic resistance genes, with gyrA, gyrB, MacA and MacB present in all analyzed genomes. One Cff strain (CFF09A980) from bovine harboured tetracycline and streptomycin resistance genes, tet(44) and ant(6)-Ib. AnotherCftstrain (772) isolated from a human host had the tetracycline gene, tet(o). A total of 185 virulence factors were identified from the 23 genomes with each genome having exactly eight virulence factors: flgC, fliQ, fliM, fliN, fliP, fliI, pseB, and cheY. There were 63 prophage elements detected, but only four were intact. There were no protein family exclusive to only one strain. Proteomic analysis showed that Cft strains Sp3 and 772 have the least percentage identity to the reference genome. Phylogenetic tree of the 23 Cf genomes clustered in two major groups; Cft strains clustered together while Cfv, Cfvi and Cff were on one major clade. Conclusion: These findings provide greater insights into the degree of pathogenicity and genomic diversity of complete genomes of Cf.