Longitudinal prevalence, faecal shedding and molecular characterisation of Campylobacter spp. and Salmonella enterica in sheep

Vet J. 2014 Nov;202(2):250-4. doi: 10.1016/j.tvjl.2014.08.001. Epub 2014 Aug 7.

Abstract

Faecal excretion of Campylobacter spp. and Salmonella enterica in sheep in Australia was determined using a quantitative multiplex PCR (qPCR) targeting the Campylobacter spp. purine biosynthesis gene (PurA) and the S. enterica outer membrane protein (ompF). The mutiplex qPCR was specific and Campylobacter spp. and S. enterica were each detected with a sensitivity of 5 organisms/µL faecal DNA extract. This multiplex qPCR was used to determine the prevalence and concentration of Campylobacter spp. and S. enterica in 3412 faecal samples collected from 1189 lambs on eight farms across South Australia (n = 2 farms), New South Wales (n = 1), Victoria (n = 2) and Western Australia (n = 3) at three sampling periods (weaning, post-weaning and pre-slaughter). The overall prevalences of Campylobacter spp. and S. enterica were 13.3% and 5.0%, respectively, with the highest prevalence for Campylobacter spp. in South Australia and the highest prevalence for S. enterica in New South Wales. Campylobacter jejuni was the only Campylobacter sp. identified from a subset of 120 positive samples sequenced at the 16S locus. S. enterica serovar Typhimurium was the only serovar of S. enterica identified from a subset of 120 positive samples sequenced at the ompF locus. Across all states, Campylobacter spp. had the highest median bacterial concentration in faeces at weaning and post-weaning (medians of 3.4 × 10(6) and 1.1 × 10(5), respectively), whereas S. enterica had the highest median bacterial concentration at pre-slaughter (1.8 × 10(5)/g faeces).

Keywords: Campylobacter spp; Quantitative PCR; Salmonella enterica; Sheep; ompF; purA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Australia / epidemiology
  • Bacterial Shedding
  • Campylobacter / isolation & purification*
  • Campylobacter Infections / epidemiology
  • Campylobacter Infections / microbiology
  • Campylobacter Infections / veterinary*
  • Feces / microbiology
  • Longitudinal Studies
  • Multiplex Polymerase Chain Reaction / veterinary*
  • Prevalence
  • Salmonella Infections, Animal* / epidemiology
  • Salmonella Infections, Animal* / microbiology
  • Salmonella enterica / isolation & purification*
  • Seasons
  • Sheep
  • Sheep Diseases* / epidemiology
  • Sheep Diseases* / microbiology