Antimicrobial Resistance Patterns and flaA Genotypes of Campylobacter jejuni Isolated from Contracted Broiler Farms in Eastern Thailand

Abstract

The increasing incidence of antibiotic-resistant Campylobacter has become a major public health concern. Since little is known about antimicrobial resistance of Campylobacter isolated from contracted broiler farms, the major type of farm that produces chicken meat for domestic consumption in Thailand, the objective of the present study was to determine the antimicrobial resistance patterns and genotypes of Campylobacter isolated from contracted broiler farms where antibiotics were routinely used in their production. Sixty-nine Campylobacter jejuni isolates from cloacal swabs of chickens reared in 2 small contracted broiler farms in eastern Thailand were tested for their susceptibility to 5 antimicrobial agents by the agar dilution method. Then, eighteen isolates were further genotyped by flaA short variable region (flaA SVR) sequencing. The majority of C. jejuni tested were resistant to ciprofloxacin (95.65%), followed by tetracycline (84.06%) and ampicillin (34.78%). Approximately 35% of the isolates were multidrug-resistant strains. The most common resistance pattern observed was CIP-TET resistance (30 isolates), followed by CIP-TET-AMP resistance (23 isolates). The main Campylobacter genotype found in this study was flaA SVR allele number 287 (8 isolates), followed by flaA SVR allele number 783 (5 isolates). No concordant between flaA SVR allele number and antibiotic resistance pattern was noticed. The high resistance rate to certain antimicrobial agents observed in the present study suggests that routine monitoring of antimicrobial resistance of Campylobacter in contracted broiler farms should be conducted.