Characterization of anti-clostridial effects of a novel probiotic

Necrotic enteritis is an enteric disease primarily caused by overgrowth of Clostridium perfringens (CP) in the small intestine following a variety of predisposing factors. The objective was to determine if a novel probiotic showed anti-clostridial effects, survived pelleting temperatures and harsh environment of the gastrointestinal tract (GIT), and if anti-clostridial effects were retained through the GIT. The probiotic was tested against 8 strains of CP to determine overarching anti-clostridial effect. The probiotic suppressed all 8 strains of CP significantly (P < 0.05) when CP inoculated media was overlaid onto a pregrown colony of probiotic and zones of inhibition measured. Next, probiotic efficacy was compared against common antibiotics and commercial probiotics. Two antibiotics, penicillin (0.0625 mg/mL) and metronidazole (0.05 mg/mL), both commercial probiotics, and the experimental probiotic reduced CP growth with the experimental probiotic outperforming both commercial probiotics (P < 0.001) and metronidazole (P = 0.007). The CP strain showed resistance to the third antibiotic, BMD (0.022 mg/mL). A germination and sporulation assay was run to ensure the spores could survive pelleting. A lack of significant change (P= 0.112) in cell recovery was indicated the probiotic’s ability to endure pelleting. A simulation digestive assay was performed mimicking the crop, proventriculus, and intestines to ensure the probiotic could survive digestion. When spores recovered from each section of the GIT were compared, the final concentration was significantly lower than the initial (P = 0.018) with a 2-fold reduction reaching the small intestine. The digestive assay was repeated with the addition of CP in the small intestines to determine if anti-clostridial properties were maintained. Using a 10⁶ dose of spores, the reduction in CP was significant at P= 0.103. The results of the experiments indicate the probiotic is a candidate for treatment and control of necrotic enteritis due to its broad anti-clostridial properties and resilience in harsh environments.

Key Words: probiotic, poultry, necrotic enteritis, antibiotic alternatives, direct-fed microbial.

Presented at the 9th Symposium on Gut Health in Production of Food Animals, St. Louis, USA, 2021. For information on the next edition, click here.