Whole-Genomic Analysis of Antimicrobial Resistance in Campylobacter jejuni in Ethiopia, Kenya and Tanzania: A One Health Approach

Campylobacter jejuni is a zoonotic bacterium causing foodborne gastroenteritis in humans worldwide, whose main symptom is diarrhea. The infection is severe mostly in children and in immunocompromised individuals. Currently, the bacterium has become increasingly resistant to antibiotics, especially those first-choice drugs used to treat campylobacteriosis posing a significant health threat towards the treatment outcomes. The burden of campylobacteriosis and Antimicrobial Resistance (AMR) remains significant with limited genomic surveillance. This study aimed to characterize the resistome (ARGs), virulence factors as well as population structure across Homo sapiens, Milk (from dairy cattle), goat, Bos indicus, Ovis aries, and Gallus gallus in three countries Ethiopia, Kenya and Tanzania through the use of One Health Whole Genome Sequencing (WGS) approach. A total of 161 C. jejuni publicly available WGS were retrieved from NCBI database and analyzed by using established WGS bioinformatics pipelines from genome assembly and annotation, AMR gene identification via ResFinder -ABRIcate, virulence genes were detected via ABRicate/ VFDB. Visualization of gene distribution and population structure were done using heatmap, Venn diagrams, principal component analysis and minimum spanning tree for comparative analysis. Out of 161 C. jejuni WGS, 130 (80.75%) sequences were positive to one or more than one ARGs. Among detected ARGs, the resistome was dominated by {beta}-lactam (blaOXA 193, blaOXA-61, blaOXA-184 and blaOXA-489) genes. Two genes linked to tetracycline resistance (tet(O/32/O), and tet(O) were found in Ethiopia and Tanzania while resistance to aminoglycoside ant (6)-Ia was the least detected. The Gallus gallus-Homo sapiens transmission (zoonotic transmission) was portrayed by the overlap of ARGs (blaOXA-193 and tet(O) and PCA clustering. The conserved virulence gene profiles were shared by all isolated (cadF, jlpA, cdtA, cdtB, cdtC and flagellar genes). The present study adds to the current knowledge on molecular epidemiology and AMR development in C. jejuni species in Eastern African countries and globally. The findings underscore the need for sustained region-specific genome surveillance under One Health framework to inform AMR stewardship and public health interventions.