Protective effect of Enterococcus faecium J96, a potential probiotic strain, on chicks infected with Salmonella pullorum

Enterococcus faecium J96 was isolated from a healthy free-range chicken and it inhibited Salmonella Pullorum, in vitro, due to its lactic acid and bac teriocin production. Ln vivo assays were carried out with 30-h-old broiler chicks. The lactic acid bacteria (similar to 1 x 10(9) cells per chick) wer e orally administered as preventive and as therapeutic treatments. In the f irst case they were given to the chicks twice a day for 3 consecutive days. In the second case the lactic bacteria were administered in the same way a fter a 24-h challenge by Salmonella Pullorum tin both instances the salmone lla dose was 1 x 10(5) cells per chick). Cecal contents, liver, and spleens were analyzed and liver and spleen fragments were also fixed in formaldehy de (pH 7.00) in order to determine salmonella translocation. The chickens t hat were preventively treated with E, faecium J96 survived the Salmonella P ullorum challenge. Those that were infected on the first day and then inocu lated with lactic bacteria died 4 days later. Salmonellae were isolated fro m their livers and spleens. From these results we may conclude that E. faec ium J96 can protect newly hatched chicks from Salmonella Pullorum infection but cannot act as a good therapeutic agent.