Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

Tracking a naturally recombinant Campylobacter by WGS (#112)

Jillian Templeton 1 , Jan-Maree Hewitson 1 , Amy Jennison 2 , Pat Blackall 3
  1. AgriScience Queensland, DAF Queensland, BRISBANE, QLD, Australia
  2. Forensic and Scientific Services, Health Support Queensland, Deparment of Health, Queensland, BRISBANE, QLD, Australia
  3. QAAFI, The University of Queensland, BRISBANE, QLD, Australia

Campylobacter jejuni and Campylobacter coli remain a key cause of human gastrointestinal disease in Australia. Poultry meat is a common, although not a sole, source of these pathogens. In an industry funded project, examining the distribution of genotypes of C. jejuni across Australia over a three year period in chicken caeca collected at the slaughterhouse, we encountered isolates that were initially confusing in terms of species identification.  The isolates were both positive in the mapA PCR regarded as specific for C. jejuni and positive in the cueE PCR regarded as specific for C. coli. In Year 1, we examined chickens in Queensland, NSW, Tasmania, WA and SA, all from one major national poultry company. The unique double-positive isolates were present only in NSW chickens.  In Year 2, we examined chickens sourced from four different companies with the source farms densely populating a very small area outside Sydney. All companies (including the national company from year 1) yielded the double positive isolates. In year 3, we examined chickens from three companies with farms in a relatively dense poultry production region outside Brisbane.  Only chickens from the national company examined in Year 1 were positive for the double-positive isolates. Whole genome sequencing and bioinformatics analysis of two representative double-positive isolates has been performed.  The analysis showed that the two isolates were a novel ST. Core genome MLST analysis grouped the two isolates in with C. coli and found only a four gene difference in the two isolates. The results suggest this clone represents a C. coli strain that has acquired the mapA gene of C. jejuni. As well, the temporal and geographical distribution suggests that the strain has moved from NSW to Queensland in recent times. Further, in the more densely poultry production system outside Sydney, local horizontal transmission between farms of different companies has occurred. Local transmission was not detected in Queensland, perhaps due to the lower density of poultry farms.