Comparison of enrichment procedures for shiga toxin-producing Escherichia coli in wastes from commercial swine farms.
Three methods for enrichment of Shiga toxin-producing Escherichia coli (STEC) were compared using waste pit samples from swine production facilities housing 50 to 3,000 animals. The STEC gene stx2 was detected in 5 of 17 pooled samples using a U.S. Department of Agriculture (USDA) enrichment procedure, 6 of 17 samples using a U.S. Food and Drug Administration (FDA) enrichment procedure, and 8 of 17 samples using an experimental acid enrichment. All isolates were non-O157 and 5 of 6 were positive for enterotoxigenic E. coli-associated heat stable toxins a and b. The three enrichment procedures were also tested for their ability to support growth of 31 strains of STEC. The acid enrichment media supported growth of 100% of the strains, the FDA medium supported 77% of the strains, and the USDA medium supported 16% of the strains.
US Food and Drug Administration, Bothell, Washington 98021-4421, USA. mike.grant@fda.hhs.gov
Michael A
MA
Grant
Mark A
MA
Mogler
Delbert L
DL
Harris
D000818:Animals; D015169:Colony Count, Microbial / Q000379:methods*; D003470:Culture Media / Q000737:chemistry*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D022621:Shiga Toxin / Q000096:biosynthesis; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification* / Q000378:metabolism; D013552:Swine
D003470:Culture Media; D022621:Shiga Toxin