Shiga toxin-producing Escherichia coli, faecal coliforms and coliphage in animal feeds.
OBJECTIVE
Animal feeds (n = 226), collected from pastures or feeding troughs on UK farms and from feed manufacturers' bulk stores, were analysed for Escherichia coli harbouring shiga-toxin genes (stx), faecal coliforms, coliphages and stx-harbouring bacteriophages.


RESULTS
Samples comprised of 79 fresh grasses, 26 silages and 121 dried or heat-processed feeds (DPF). Five of the 79 (6.3%) fresh grass samples contained stx(2)-E. coli. stx-E. coli were not detected in the silages or DPF that were examined. Faecal coliforms were detected in 75/79 (94.9%) of fresh grasses, 19/26 (73.1%) of silages and 36/121 (29.8%) of processed feeds. Coliphages were detected in 63/79 (79.7%) and 18/26 (69.2%) of fresh grasses and silages, respectively. Coliphages were isolated at a significantly lower prevalence of 5% (6/121) from processed feeds. Although stx(2)-phage was isolated from the enrichment of a single grass sample, stx-phages were not detected in any of the silage or processed feeds. We did not detect stx(1)-phage in any of the samples collected.


CONCLUSIONS
Pastures have the potential to act as transmission vectors for stx-harbouring E. coli for grazed livestock.


CONCLUSIONS
This is the first study to report on the prevalence of E. coli harbouring stx genes, faecal coliforms, coliphages and stx-harbouring bacteriophages in a range of feedstuffs destined for consumption by UK livestock. This study provides information on the risk of feeds to the spread of stx-phages between livestock and/or the environment.
Hutchison
M L
ML
Research Division, DLS-Eurofins, Wolverhampton, UK. mike.hutchison@directlaboratories.net
Thomas
D J I
DJ
Walters
L D
LD
Avery
S M
SM
D000821:Animal Feed / Q000382:microbiology*; D003090:Coliphages / Q000254:growth & development / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D004755:Enterobacteriaceae / Q000254:growth & development / Q000302:isolation & purification*; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D006109:Poaceae / Q000382:microbiology; D022603:Shiga Toxins / Q000096:biosynthesis*
D022603:Shiga Toxins