Identification of antimicrobial resistance profiles and antimicrobial resistance genes of Campylobacter isolates from broiler farms in Sri Lanka
Authors:   Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan. & Department of Livestock Production, Faculty of Agricultural Sciences, Sabaragamuwa University of Sri Lanka, P.O. Box 02, Belihuloya 70140, Sri Lanka., Liyanage Champika Sajeewa Perera Jayasundara , Pathmalal Marakkale Manage ,   Department of Zoology, University of Sri Jayewardenepura, Sri Soratha Mawatha, Nugegoda 10250, Sri Lanka., De Silva Dehinga Prasadi Nayanashani ,   Department of Chemistry, Faculty of Science, University of Colombo, Colombo 00700, Sri Lanka., Miura Kozue ,   Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan., Yamada Akio ,   Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan., Hirayama Kazuhiro ,   Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan. & Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan.
Published: January 2024

Antimicrobial resistant (AMR) bacteria including Campylobacter has become an emerging global concern in human and animal health. There are very few researches on AMR Campylobacter conducted in Sri Lanka and none of them studied about AMR genes to the best of our knowledge. The present study focused on the detection of AMR Campylobacter from broiler in Sri Lanka, resistant against frequently used antimicrobials. Further, presence of AMR genes or mutations in responsible genes were compared to the resistant phenotypes. Cloacal swabs were collected from 118 broilers in nine farms covering three provinces in Sri Lanka. One Campylobacter colony per sample was isolated and the antimicrobial susceptibility test of the isolates was performed by inoculating the isolates onto agar plates with threshold concentrations of eight antimicrobial agents which belong to six antimicrobial classes. Three genetic markers for antimicrobial resistance, point mutations in 23S rRNA gene and gyrA gene, and the presence of resistant gene, tet(O) were also investigated. Altogether, 73 samples were Campylobacter positive of which 59 were Campylobacter jejuni, 13 were Campylobacter coli and one was unidentified Campylobacter. All isolates were resistant to three or more antimicrobials tested. The isolates were frequently resistant to ciprofloxacin, nalidixic acid, trimethoprim-sulfamethoxazole, amoxicillin and tetracycline, and susceptible to gentamicin and streptomycin, while the resistance to erythromycin was different between the species. Genetic screening revealed that most of the isolates possessed one or more of these genetic markers. This study urges the need of continuous surveillance for AMR Campylobacter in Sri Lanka.