Reduction of Salmonella in gnotobiotic Japanese quails caused by the enterocin A-producing EK13 strain of Enterococcus faecium.

The effect of the enterocin A-producing EK strain of Enterococcus faecium on Salmonella dusseldorf SA31 was tested in gnotobiotic Japanese quails. Sixteen 3-day-old gnotobiotic Japanese quails, hatched from disinfected eggs placed in sterile boxes, were divided into two groups of 8 birds: a control group, which was inoculated orally with the SA31 strain (1 x 10(7) CFU/ml), and the experimental group, which was inoculated orally with 200 microl of E. faecium (1 x 10(9) CFU/ml), 16 h before infection with the S. dusseldorf. The latter group then received the same average dose of E. faecium daily in drinking water. Faecal samples were taken 8, 24, 48 and 168 h after the inoculation of S. dusseldorf and examined for S. dusseldorf and E. faecium (EK13). The quails were then killed and the number of the EK13 strain of E. faecium and of S. dusseldorf in the caecum and ileum were estimated. A reducing effect of the EK13 strain against the SA31 strain in faeces was detected in the samples taken at 24 and 48 h from the group with the EK13 strain. Significant reductions were also found in the numbers of S. dusseldorf SA31 strain in the caecum but not in the ileum.