Targeting Enterococci with Antimicrobial Activity against Clostridium perfringens from Poultry

Area of Science:

• Microbiology
• Poultry Science
• Antimicrobial Peptides

Background:

• Necrotic enteritis (NE), caused by *Clostridium perfringens*, is a significant concern in poultry farming.
• There is a critical need for antibiotic alternatives to manage NE and combat multidrug-resistant bacteria.
• *Enterococcus* species produce enterocins, antimicrobial peptides effective against pathogens, making them potential protective cultures.

Purpose of the Study:

• To screen and characterize *Enterococcus* strains from poultry for their ability to inhibit *C. perfringens*.
• To identify promising *Enterococcus* strains as natural alternatives for necrotic enteritis prevention in poultry.

Main Methods:

• Screened 251 poultry-origin *Enterococcus* strains and 5 *E. durans* strains for antimicrobial activity against *C. perfringens* using the 'spot on the lawn' method.
• Evaluated inhibitory activity of 32 bacteriocin-producing (BP+) strains against 20 *C. perfringens* strains via agar well diffusion and microtitration.
• Performed whole genome sequencing on 12 promising BP+ enterococci.

Main Results:

• Identified 32 bacteriocin-producing (BP+) *Enterococcus* strains, including *E. faecium*, *E. gallinarum*, *E. faecalis*, *E. durans*, and *E. casseliflavus*.
• Twelve BP+ enterococci demonstrated significant antimicrobial activity against *C. perfringens*.
• *E. faecium* strains X2893 and X2906 were most effective, possessing enterocin A/B genes, lacking acquired resistance genes and plasmids, and containing the *acm* colonization gene.

Conclusions:

• *Enterococcus* strains, particularly *E. faecium* X2893 and X2906, show potential as protective cultures against necrotic enteritis in poultry.
• These strains offer a promising antibiotic-free strategy for poultry health.
• Further research is required to validate their efficacy as protective cultures in poultry farming.