Fluoroquinolone resistance and phylogenetic analysis of broiler Campylobacter jejuni isolates in Indonesia

Consumption of poultry contaminated with Campylobacter jejuni is the main source of sporadic campylobacteriosis in humans, while fluoroquinolone resistance is increasing in Campylobacter jejuni isolated from poultry. The aim of this study was to detect the incidence of fluoroquinolone resistance and analyze phylogenetics by sequencing gyrase subunit A from broiler Campylobacter jejuni isolates. The contents of 200 chicken intestines were taken from chicken farms in 4 sub-districts (Sukorejo, Pandaan, Kejayan, and Grati) in Pasuruan Regency, Indonesia. The Kirby-Bauer Diffusion Test method is used to detect fluoroquinolone resistance phenotypically. Polymerase chain reaction is used to detect fluoroquinolone resistance genotypically through detection of the gyrA gene. A phylogenetic tree based on gyrA genes was created using MEGA12. The results showed that 31 Campylobacter jejuni isolates had high resistance to nalidixid acid (100%), enrofloxacin (96.7%), and ciprofloxacin (93.6%). All Campylobacter jejuni isolates (100%) were fluoroquinolone resistant phenotypically and had the gyrA gene genotypically. Phylogenic analysis showed that the Campylobacter jejuni gyrA gene sequence isolated from broilers from different sub-districts were highly related. Sequence results from broilers with gyrA gene sequences from humans appear to be in the same cluster, indicating that zoonotic transmission can occur. The discovery of a high percentage of fluoroquinolone resistance genes, where fluoroquinolone is the first line drug for the treatment of diarrhea in humans, should certainly be an important issue related to human health.