Evaluation of the probiotic potential of Enterococcus faecium NCIMB 11181 as a possible candidate in animal nutrition

Abstract Enterococcus faecium (NCIMB 11181) was evaluated for survivability, safety, and capacity as probiotics utilization. Gram-positive, catalase-negative test, antibiotics susceptibility, hemolysis activity, pH and bile salts resistance were screened using selective microbiological media. The strain was phenotypically assessed for its principal probiotic properties. The capacity of fermentation based on biochemical tests was evaluated by API 20STREP and interpretation by apiwebTM Biomerieux (France) software (99.2% very good identification). After incubation at 37°C for 22-24 h in aerobic conditions, E. faecium involves 13.96 Log10 with an optical density (OD 600 nm) from 0.2 in the first 2 hours of growth to 0.9 value. The safety assessment on TSA agar showed that the strain revealed α-hemolysis. Resistance to 16 clinically relevant antibiotics, presented for our strain a range from intermediate (81.25%) to susceptible (6.25%), followed by resistance to erythromycin and colistin sulfate. The strain exhibited tolerance to acidic conditions and simulated gastric environment. Therefore, E. faecium NCIMB 11181 can be considered a safe strain without creating a risk to animal health status. It may be used as a probiotic preparation product for application in animal nutrition.