bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.02.16.638542

Genomic Insights into the Diversity, Antimicrobial Resistance, and Zoonotic Potential of Campylobacter fetus Across Diverse Hosts and Geographies

Abstract

BackgroundCampylobacter fetus causes reproductive diseases in livestock and zoonotic infections in humans, especially in immunocompromised individuals. Despite its significance, its genomic characteristics are poorly understood. This study analyzed 114 publicly available C. fetus genomes to provide global insights into its genetic diversity, antimicrobial resistance (AMR) patterns, and zoonotic risk. ResultsA total of 32 distinct sequence types (STs), ranging from ST-1 to ST-74, were identified across 111 of the 114 C. fetus genomes, spanning six continents and diverse hosts (cattle, humans, sheep, and reptiles). ST-4 was the most prevalent (n = 45), followed by ST-3 (n = 8). A significant proportion (90.9%; n/N=40/44) of C. fetus subsp. venerealis (Cfv) and its biovar intermedius (Cfvi) were assigned to ST-4. Despite being isolated from five continents, Cfv and Cfvi genomes clustered closely, forming distinct branches at the biovar level; however, six Cfv genomes were located within Cfvi clades, suggesting a shared evolutionary lineage. In contrast, C. fetus subsp. testudinum (Cft) genomes, exhibiting 20 distinct STs, formed distinct clades from Cfv, Cfvi, and C. fetus subsp. fetus (Cff). While Cfv genomes from North America and Cfvi genomes from South America formed distinct geographic clusters, Cff genomes displayed no clear geographical patterns, with branches containing strains from multiple continents, indicating a globally dispersed distribution. Pangenomic analysis revealed pronounced clustering within Cft, characterized by unique gene presence/absence patterns. Five distinct AMR genes were detected, with tet(O) (n = 3) being the most common. Horizontal gene transfer analysis identified 140 genomic islands across 41 genomes, and virulence factor analysis revealed cheY as the sole conserved virulence gene across 35 genomes. ConclusionThese findings provide critical insights into the genomic diversity, zoonotic potential, and global distribution of C. fetus, emphasizing the need for integrated genomic and epidemiological strategies to assess its impact on human and animal health.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Paintsil, E. K., Adu-Asiamah, C. K., Boahen, K. G., Akenten, C. W., Kwarteng, A., Berg, S., Obiri-Danso, K., May, J., Dekker, D., Ofori, L. A.. 2025-02-19. Genomic Insights into the Diversity, Antimicrobial Resistance, and Zoonotic Potential of Campylobacter fetus Across Diverse Hosts and Geographies. https://doi.org/10.1101/2025.02.16.638542

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Integrative Nanopore and Illumina sequencing reveals age-associated tRNA modification and CCA-tail dynamics in yeast

Aging is characterized by a progressive loss of proteostasis. Transfer RNAs (tRNAs) are essential regulators of translation, yet their dynamics during aging remain poorly understood due to challenges in sequencing highly modified RNAs. Here we present a benchmarked Nanopore direct RNA sequencing (RNA004 chemistry) resource that profiles the Saccharomyces cerevisiae tRNAome during replicative aging at single-molecule resolution. Using in vitro transcribed tRNA controls, we establish modification detection thresholds and validate key findings with orthogonal Illumina sequencing. While overall tRNA abundance remains largely stable, our resource reveals age-associated terminal A cleavage at the 3' CCA tail of mature tRNAs, targeted T-loop and anticodon modification changes, and single-molecule evidence of modification co-occurrence. This dataset provides a resource for exploring tRNA regulation, translation fidelity, and longevity.

genomics↗

A hydrogen-producing mitochondrion in an anaerobic eukaryotrophic rhizarian

Diverse eukaryotes thrive under low oxygen conditions, in part through highly modified mitochondrion-related organelles (MROs) that use alternate metabolic pathways to support ATP production and cofactor recycling. Anaerobic lifestyles have evolved repeatedly across the eukaryotic tree of life, each providing an independent opportunity to understand how eukaryotes adapt to life in low oxygen conditions. Here, we use single-cell transcriptomics to reconstruct the MRO metabolism of PCE SSF, a benthic eukaryotrophic flagellate and the first cultivated representative of Novel Clade 12 (NC12; Rhizaria), an independently anaerobic rhizarian lineage. PCE SSF possesses an anaerobic hydrogen-producing mitochondrion capable of hydrogenosome-type substrate-level phosphorylation. It also retains a nearly complete but likely branched tricarboxylic acid pathway that lacks citrate synthase and malate dehydrogenase. The function of citrate synthase may instead be fulfilled by the typically cytosolic ATP citrate lyase, previously reported in this context only in the anaerobic cercozoan, Brevimastigomonas motovehiculus. Unlike B. motovehiculus, however, PCE SSF retains only Complex II and the NuoE/NuoF subunits of the electron transport chain and lacks a mitochondrial genome. Together, these features indicate an atypical and reduced mitochondrial metabolism, highlighting the diversity of evolutionary solutions to anaerobic energy metabolism in eukaryotes.

genomics↗

Targeted CRISPRi screening reveals unexpected resilience across the RNA polymerase III transcriptome

Increased RNA polymerase III (Pol III) activity and tRNA abundance are widely linked to cancer cell growth, yet the functional requirement for individual Pol III genes and core components remains unclear, in part due to the difficulty of achieving gene-specific perturbation of highly conserved loci. Here, we developed an inducible CRISPR interference platform and a custom single-guide RNA (sgRNA) library enabling gene-specific targeting of Pol III-transcribed genes and Pol III machinery. Genome-wide screening identified several Pol III dependencies in diploid fibroblasts and HEK293T cells, including multiple initiator methionine tRNA genes among the strongest fitness dependencies. Unexpectedly, glioblastoma models remained largely insensitive to repression of both individual Pol III genes and core Pol III components, despite efficient target repression. These findings establish a general strategy for gene-specific interrogation of conserved Pol III genes and indicate that glioblastoma models tolerate extensive perturbation of Pol III genes and machinery.

genomics↗