PS-216 Antagonistic Activities against NCTC 11168 Are Modulated by Temperature, Oxygen, and Growth Medium.

As the incidence of and campylobacteriosis grows, so does the need for a better understanding and control of this pathogen. We studied the interactions of NCTC 11168 and a potential probiotic, PS-216, in cocultures at different starting ratios and temperatures (20 °C, 37 °C, 42 °C), under different atmospheres (aerobic, microaerobic), and in different growth media (Mueller-Hinton, chicken litter medium, chicken intestinal-content medium). Under microaerobic conditions, effectively inhibited the growth of at 42 °C (log reduction, 4.19), even when counts surpassed by 1000-fold in the starting inoculum. This inhibition was weaker at 37 °C (log reduction, 1.63), while no impact on CFUs was noted at 20 °C, which is a temperature nonpermissive of growth. Under aerobic conditions, supported survival. PS-216 inhibited the growth of in sterile chicken litter (4.07 log reduction) and in sterile intestinal content (2.26 log reduction). In nonsterile intestinal content, PS-216 was able to grow, to a lesser extent, compared to Mueller-Hinton media, still showing potential as a chicken probiotic that could be integrated into the chicken intestinal microbiota. This study showed the strong influence of environmental parameters on the variability of and interactions. Furthermore, PS-216 antagonism was strongest against NCTC 11168 under conditions that might represent conditions in the chicken environment (42 °C, microaerobic atmosphere, chicken litter medium).