Creation and characterisation of probiotic libraries for use in poultry and pigs

Probiotics are defined as live micro-organisms which provide the host with a growth or health advantage. In recent year’s with the emergence of antimicrobial resistance, probiotics, and in particular Lactobacillus, have become increasingly popular as an alternative control strategies for bacterial pathogens. Recent studies have demonstrated that Lactobacillus is not only able to increase the growth rate of animals, an important consideration for commercial farming entities, but is also able to inhibit the colonisation of animals with pathogenic bacteria species such as Salmonella, Campylobacter and Escherichia. This study aimed to isolate and characterise lactobacilli isolates from commercially reared chickens and pigs. Particular attention was paid to the probiotic potential of the isolates. Our approach combined molecular techniques with in vitroscreening to rapidly identify this potential. To date 80 and 105 isolates have been collected from pigs and chickens, respectively. All isolates have been confirmed to belong to the Lactobacillus genus by PCR, speciated by 16S sequencing and determined to be clonally unique using RAPD PCR. Isolates were subsequently tested for their ability to tolerate low pH, bile, aerobic and anaerobic conditions before assessing their AMR profile and determine their ability to inhibit a panel of clinical and type strains of pathogenic bacteria. Isolates identified as potential probiotics are currently undergoing whole genome sequenced as per EFSA guidelines. This study has demonstrated that lactobacilli isolates with suitable probiotic properties can be isolated from commercial poultry and pigs. Furthermore, these isolates may prove useful as control strategies for zoonotic bacterial pathogens.