MANAGEMENT
Selective removal of Salmonella from broilers using a novel technology A new CRISPR-based patented technology has been developed that promotes the selective removal of specific unwanted bacteria by inducing self-destruction. This technology, designed to remove all Salmonella serovars and introduced into a vector Escherichia coli probiotic for delivery, was tested in the current trial in broilers challenged by the introduction of Salmonella enteritidis-positive seeder birds at 5 days of age.
T. Cogan1 H. Kneuper2 H. Graham2 M.J. Woodward2 1
2
Bristol Veterinary School, University of Bristol, UK
Folium Science, Bristol, UK
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Three groups each of 45 as-hatched Ross 308 chicks were used, with one group as a Control and the other groups supplied via drinking water with either the E. coli vector probiotic alone or with an anti-Salmonella plasmid included (Guided Biotics™). Caecal samples (15 per group) were taken at day 12 (7 days after introduction of three Salmonella colonized seeder birds per group) for Salmonella counts (both direct and enhanced), and bird liveweight was recorded at 42 day. All 30 birds tested in the Control and vector-only groups were Salmonella positive at
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day 12 with the enhanced method, with caecal counts of 500-4,000,000 CFU/g, while 22 were positive by the direct count method. Inclusion of the vector + plasmid combination in the drinking water resulted in no detection of Salmonella in any birds using direct counts, whilst 8 of the 15 birds tested Salmonella free with enhanced counts. This combination also reduced the mean Salmonella counts by approximately log-3 (P<0.001). The birds in the vector + plasmid group were 15% heavier (P=0.02) than the
