Prevalence and Antimicrobial Resistance of Salmonella and Campylobacter Species Isolated from Laying Duck Flocks in Confinement and Free-grazing Systems

Abstract

Prevalence and antimicrobial resistance of Salmonella and Campylobacter species isolated from duck laying flocks in 7 confinement systems and 7 free-grazing systems were determined in central Thailand. In the confinement system, 13.8% (88/639) of Campylobacter spp. were isolated from cloacal swabs; 72.7% was identified as C. jejuni and 27.3% was identified as C. coli. From drinking and surface water samples, 60.0% of Campylobacter spp. were isolated; all was identified as C. jejuni. In the free-grazing system, 0.3% (2/700) of Campylobacter spp. were isolated from cloacal swabs; all was identified as C. jejuni. In addition, 52.9% was isolated from drinking and surface water samples; all was identified as C. jejuni. Between 67.9% and 81.0% of all C. jejuni isolated from both systems was resistant to Streptomycin, Nalidixic acid, Ciprofloxacin, and Levofloxacin. Between 50.0% and 87.5% of all C. coli isolated from both systems was resistant to Streptomycin, Nalidixic acid, Ciprofloxacin, and Levofloxacin. In the confinement system, Salmonella spp. isolated from cloacal swabs, feed, soil, and water samples were 4.2%, 13.3%, 57.1% and 33.3%, respectively. Among them, 14 serotypes of Salmonella spp. were identified. In the free-grazing system, Salmonella spp. isolated from cloacal swabs, feed, soil, and water samples were 10.7%, 25.0%, 70.0% and 47.1%, respectively. Among them, 20 serotypes of Salmonella spp. were identified. Only one sample (S. Typhimurium) from the confinement system was resistant to Cephalothin. Four serotypes (S. Agona, S. Stanley, S. Thompson, and S. Corvallis) of five samples from 5 free-grazing flocks were resistant to antimicrobial agents. Consequently, in the confinement system there was a higher prevalence of Campylobacter spp. from cloacal swabs than Salmonella spp. On the contrary, in the free-grazing system there was a higher prevalence of Salmonella spp. from cloacal swabs than Campylobacter spp.