Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

Campylobacter transmission in Australian free-range broiler flocks (#80)

Pongthorn Pumtang-on 1 , Tim Mahony 2 , Rod Hill 1 , Thiru Vanniasinkam 1
  1. School of Biomedical Science, Charles Sturt University, Wagga Wagga, NSW, Australia
  2. Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, Australia

Chicken meat is regarded as a major source of Campylobacter infection in humans. Understanding the dynamics of Campylobacter transmission in chicken flocks could provide the knowledge required to develop effective interventions for Campylobacter control at the farm level. However, information on the sources and timing of Campylobacter colonisation of Australian free-range chicken farms is limited. This study aimed to investigate the source(s) of Campylobacter jejuni and C. coli colonisation and transmission in free-range broiler chickens in New South Wales, Australia. Samples from broiler farms and breeder farms were obtained and tested using culture, mass spectroscopy and multiplex qPCR. The results of this study showed that C. jejuni is the predominant species in broiler flocks. C. jejuni and/or C. coli were detected in the farm environment before chick placement in two flocks and C. coli was detected in one broiler flock when chicks were 10 days old. The highly variable flaA gene of Campylobacter was selected for genotyping using a High-Resolution Melt PCR (HRM-PCR). All C. jejuni and C. coli genotypes isolated from broiler flocks were further characterised by Multilocus Sequence Typing (MLST). Using these methods nine genotypes of C. jejuni and five genotypes of C. coli were identified. Two C. jejuni genotypes (ST-257 complex and ST-45 complex) were identified as the predominant genotypes. While, flaA allele no 36 was the predominant C. coli genotype. The same C. jejuni and C. coli genotypes isolated from broiler flocks were found in the farm environment such as pest faeces, soils, sheds, boots and drinking water. These results suggest that horizontal transmission played an important role in C. jejuni and C. coli colonisation of broiler flocks in this study. There was minimal evidence of vertical transmission between breeder and broiler flocks. These results suggest that any intervention to reduce Campylobacter colonisation of chickens would need to be applied on broiler farms.