An in vitro investigation of the survival and/or growth of Campylobacter jejuni in broiler digestate from different feed types

Campylobacter spp. is the leading cause of bacterial gastroenteritis worldwide and poultry are the primary reservoir. The aim of this study was to investigate the survival and/or growth of C. jejuni NCTC 11168 in broiler digestate prepared from commercial starter, grower and finisher feed formulations. Bolton broth and digestates were prepared, inoculated with C. jejuni NCTC 11168 (approximately 3 log10 CFU per ml) and incubated under microaerobic conditions at 42°C for 24 hours. Samples were taken at t = 0 (immediately after inoculation) and every 3 hours thereafter, serially diluted and plated onto mCCDA. C. jejuni grew as expected in Bolton broth (control) reaching the early stationary phase after approximately 15 hours. In contrast, although bacterial concentrations were maintained for at least 9 hours, none of the feed digestates supported the growth of C. jejuni, which were not detected after 15 hours. It is suggested that the nutrients available in the feed digestates are not enough to support C. jejuni growth and that additional factors may be at play in the avian gastrointestinal tract (GIT).