High Prevalence of Fluoroquinolone-Resistant Campylobacter Bacteria in Sheep and Increased Campylobacter Counts in the Bile and Gallbladders of Sheep Medicated with Tetracycline in Feed

Xia J. , Pang J., Tang Y., Wu Z., Dai L., Singh K., ...Daha Fazla

APPLIED AND ENVIRONMENTAL MICROBIOLOGY, cilt.85, 2019 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 85 Konu: 11
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1128/aem.00008-19


Campylobacter is a major foodborne pathogen in humans and a significant cause of abortion in sheep. Although ruminants are increasingly recognized as important reservoirs for Campylobacter species, limited information is available about the molecular epidemiology and antimicrobial resistance (AMR) profiles of sheep Campylobacter. Here, we describe a two-trial study that examined Campylobacter profiles in sheep and determined whether in-feed tetracycline (TET) influenced the distribution and AMR profiles of Campylobacter. Each trial involved 80 commercial sheep naturally infected with Campylobacter. 40 of these sheep were medicated with tetracycline in feed, while the other 40 received feed without antibiotics. Fecal and bile samples were collected for the isolation of Campylobacter. The bacterial isolates were analyzed for antimicrobial susceptibility and genotypes. The results revealed that 87.0% and 61.3% of the fecal and bile samples were positive for Campylobacter (Campylobacter jejuni and Campylobacter coli), with no significant differences between the medicated and nonmedicated groups. All but one of the tested Campylobacter isolates were resistant to tetracycline. Although fluoroquinolone (FQ) resistance remained low in C. jejuni (1.7%), 95.0% of the C. coli isolates were resistant to FQ. Genotyping revealed that C. jejuni sequence type 2862 (ST2862) and C. coil ST902 were the predominant genotypes in the sheep. Feed medication with tetracycline did not affect the overall prevalence, species distribution, and AMR profiles of Campylobacter, but it did increase the total Campylobacter counts in bile and gallbladder. These findings identify predominant Campylobacter clones, reveal the high prevalence of FQ-resistant C. coli, and provide new insights into the epidemiology of Campylobacter in sheep.