The effect of feeding Streptococcus faecium upon Escherichia coli induced diarrhea in gnotobiotic pigs.

Streptococcus faecium (Sf) was fed to gnotobiotic pigs to control colibacillosis. Three strains of Escherichia coli (Ec) were used. Strain 0:K103,987p:NM of Ec fed to pigs without Sf developed severe diarrhea which persisted for several days. Those pigs given Sf and Ec had less diarrhea, recovered earlier, and had better weight gains than Ec only pigs. Two other strains of Ec (0157:K88ac:H19 and 08:K87,K88ab:H19) which were more virulent developed severe diarrhea and death in 5 of 8 pigs given Ec only. Those fed Sf and challenged with Ec developed some diarrhea, but the pigs gained weight and none of the pigs died. Bacterial counts of Ec and Sf from 3 different levels of small intestine and cecum were comparable. The counts were reduced for both organisms in those pigs with dual colonization. It would appear that feeding Sf reduced the toxic effect of Ec and prevented a generalized infection and death. Forty-eight litters of surgically-obtained colostrum-deprived specific-pathogen-free (SPF) pigs for repopulating swine production units were started on Sf probiotic; 48 preceding litters not fed Sf were used for comparison. Those fed Sf had a mortality rate of 8.5% as compared to 18% for those not fed Sf.