Colorized electron micrograph of a cluster of E.
coli bacteria. Click the image for more information about
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New Approach to Controlling E. coli in Pigs
March 4, 2004
An Agricultural Research
Service scientist at the Southern Plains
Agricultural Research Center in College Station, Texas, has come up with an
alternative to antibiotics to control Escherichia coli, the leading
cause of sickness and death in newborn and weaned pigs. Each year, the U.S.
swine industry loses millions of dollars to bacterial infections in these
vulnerable, young animals.
Roger B. Harvey, a veterinary medical officer in the ARS
Food and Feed Safety Research Unit at
College Station, leads an effort to develop a mixed culture of beneficial
bacteria that's being referred to as "RPCF"--for recombined porcine
continuous-flow. Scientists think that RPCF might one day be able to replace
today's antibiotic treatments, which are coupled with regulation of ambient
temperature, improvement in hygiene and applications of zinc oxide. A growing
resistance of E. coli to today's antibiotics makes developing an
effective replacement especially important.
Harvey's method involves colonizing young pigs' intestinal
tracts with a mixture of beneficial bacteria obtained from other pigs. This
helps establish healthy microbial populations in the gut much quicker than
would otherwise occur. These "good" bacteria attach to intestinal walls,
blocking sites so that disease-causing, "bad" bacteria can't attach and compete
for needed nutrients. Some of the colonizing bacteria also produce bactericidal
compounds that work against disease-causing pathogens, further reducing their
ability to colonize the intestinal tract.
About 35,000 pigs have been tested at four nursery farms and one
wean-to-finish operation in five different U.S. regions. These farms had
previously been diagnosed with disease caused by the F-18 strain of E.
coli. So far, the RPCF mixture of beneficial bacteria has been shown to
reduce illness, death and medication costs from E. coli infections,
compared to untreated pigs.
about this research in the
March 2004 issue of
Agricultural Research magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.