Identification of lactic acid bacteria from poultry feces: evidence on anti-campylobacter and anti-listeria activities.

Forty-five strains of lactic acid bacteria were isolated from poultry feces sampled from an industrial farm located in the Nantes area (France), and most of them belong to the Streptococcus or Lactobacillus genus according to the results obtained by Galerie API and molecular methods. The most representative lactic acid bacteria strains were screened for antibacterial compound production against 2 indicator organisms (Listeria innocua F and Campylobacter jejuni 11168) by means of the agar diffusion test. Strain S37, identified as Enterococcus faecalis, exhibited a clear anti-listerial activity and a slight anti-Campylobacter activity, whereas strain S42, identified as Lactobacillus reuteri, exhibited only anti-Campylobacter activity. Regarding the results of proteolytic, heat, and neutralizing treatments of supernatants from the aforementioned strains, we can conclude that antagonism observed is attributed to antimicrobial peptide or bacteriocin in the case of strain S37, whereas it is ascribable to a nonbacteriocin, likely a reuterin, in the case of strain S42.