Submitted to: American Society of Animal Science Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 2, 2004
Publication Date: July 25, 2004
Citation: Harvey, R.B., Anderson, R.C., Genovese, K.J., Callaway, T.R., Nisbet, D.J. Use of competitive exclusion to control enterotoxigenic strains of E. coli [abstract]. Journal of Animal Science. 82(Suppl. 1):404. Technical Abstract: Foodborne diseases, morbidity, and mortality in food-producing animals, associated with pathogenic strains of Escherichia coli, are of public health and economic significance. Increasingly, E. coli have become resistant to antibiotics and alternative control measures are sought. Our laboratory developed a defined culture of commensal bacteria of porcine GI tract origin, maintained it in continuous-flow culture, and designated it as RPCF. When administered to neonatal gnotobiotic pigs, immunoglobulin levels were increased 20- to 100-fold. In vitro laboratory studies have shown that RPCF prevented colonization of O157:H7 and F-18 strains of E. coli. Other laboratory studies demonstrated that RPCF-treated pigs had decreased mortality and bacterial shedding compared to controls when challenged with enterotoxigenic strains of E. coli. In field trials involving five geographically separated nursery farms with a history of high mortality from F-18 strain of E. coli, piglets were orally administered 10**8 CFU of RPCF within 24 h of birth, were monitored throughout the nursery period, and the performance of RPCF-treated pigs were compared to a similar number of untreated pigs on the same farms. A total of 34,676 pigs were included in these trials. Medication costs were reduced in RPCF-treated pigs compared to controls and nursery barn mortality decreased from 7.7% in untreated controls to 4.2% in RPCF-treated pigs (mean of 3.5%). Improved livability and reduced medication costs in RPCF pigs produced an annual cost benefit of $22,196 per farm. Results from the present studies indicate that under laboratory and field conditions, RPCF was effective in controlling disease induced by enterotoxigenic E. coli and may be a viable alternative to the use of antibiotics.