Occurrence and antibiotic resistance profiles of Campylobacter spp. in urban broiler production systems in Uganda

Background: Urban broiler production is rapidly expanding in East Africa, raising public health concerns about zoonotic pathogens such as <i>Campylobacter</i> and the spread of antibiotic resistance. This study investigated the occurrence, and phenotypic and genotypic antibiotic resistance of <i>Campylobacter</i> from broilers in urban and peri-urban Uganda.

Methods: A total of 194 samples, including cloacal swabs (n=157) and boot socks (n=37), were collected from 28 randomly selected farms in three districts. <i>Campylobacter</i> was isolated according to ISO 10272-1 and tested for susceptibility to nalidixic acid, ciprofloxacin, tetracycline, streptomycin and erythromycin by disk diffusion following EUCAST guidelines. Species identification and resistance genotypes were determined by whole genome sequencing. Isolates that could not be re-cultivated were excluded from further analyses.

Results: <i>Campylobacter</i> was isolated from all 194 samples (100%). Of the 157 sequenced isolates, 54% (n=84) were <i>Campylobacter coli</i> and 46% (n=73) were <i>Campylobacter jejuni</i>. Of the 170 isolates tested for antibiotic susceptibility, 16% (n=28) were resistant to all five antibiotics. No isolate was susceptible to ciprofloxacin. Multidrug resistance occurred in 61% (51/84) of <i>Campylobacter coli</i> and in 6% (4/72) of<i> Campylobacter jejuni</i> isolates. Strong concordance was observed between quinolone resistance and <i>gyrA</i> T86I mutation, tetracycline resistance and <i>tet(O/32/O)</i> or <i>tet(O)</i> genes, and in <i>Campylobacter coli</i>, streptomycin resistance and <i>ant(6)-Ia</i> gene.

Conclusions: Broilers in urban and peri-urban Uganda are frequently colonized with antibiotic resistant <i>Campylobacter</i>, highlighting the need for strengthened biosecurity and antibiotic stewardship to mitigate public health risks.