Antimicrobial resistance remains a public health concern globally. This study presents antimicrobial resistance by microdilution and genetic diversity by the whole-genome sequencing of Campylobacter spp. from human and poultry samples isolated in Georgia in 2020/2021. The major species in poultry samples was C. coli, while C. jejuni was preferentially isolated from human samples. Resistance against tetracycline was highest (100%) in C. coli from industrial chicken and lowest in C. jejuni from clinical isolates (36%), while resistance against ciprofloxacin varied from 80% in C. jejuni from backyard chicken to 100% in C. jejuni and C. coli from industrial chicken. The point mutations in gyrA (T86I) and tet (O) genes were detected as resistance determinants for (fluoro-)quinolone or tetracycline resistance, respectively. Ertapenem resistance is still enigmatic. All isolates displayed sensitivity towards erythromycin, gentamicin and chloramphenicol. Multi-resistance was more frequently observed in C. coli than in C. jejuni, irrespective of the isolation matrix, and in chicken isolates compared to human isolates, independent of the Campylobacter species. The Georgian strains showed high variability of multi-locus sequence types (ST), including novel STs. This study provides the first antibiotic resistance data from Campylobacter spp. in Georgia and addresses the need for follow-up monitoring programs.
Keywords: EUCAMP3; WGS; backyard chicken; campylobacteriosis; cgMLST; gastroenteritis; microdilution; resistance determinant; whole-genome sequencing.