Pre-slaughter handling of cattle and Shiga toxin-producing Escherichia coli (STEC).
OBJECTIVE
The aim of the study was to monitor the shedding and transmission of generic and Shiga toxin-producing Escherichia coli (STEC) in a consignment of cattle during lot feeding.


RESULTS
Faecal and environmental samples were tested for total E. coli and screened with PCR specific for Shiga toxin and O157 rfb. STEC were isolated using colony hybridization and characterized by serology and genotyping. STEC prevalence initially decreased after the diet shift from pasture to grain, although there were intermittent peaks in numbers of cattle shedding STEC and E. coli O157. Water troughs and soil were intermittently contaminated. Common genotypes and serotypes were isolated from animals, water and soil in the feedlot, with additional types introduced at slaughter.


CONCLUSIONS
STEC and E. coli O157 are endemic in cattle and intermittent peaks in shedding occur. Prevention of these peaks and/or reduction in transmission is required to reduce the risk of carcass contamination during slaughter.


CONCLUSIONS
These findings contribute to the understanding of the ecology of STEC and suggest control points for reducing STEC contamination in feedlot cattle production.
Midgley
J
J
University of Queensland, St Lucia, Australia. Jocelyn.Midgley@foodscience.afisc.csiro.au
Desmarchelier
P
P
D000003:Abattoirs; D000821:Animal Feed / Q000382:microbiology; D000822:Animal Husbandry; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002418:Cattle Diseases; D015169:Colony Count, Microbial / Q000662:veterinary; D004927:Escherichia coli Infections / Q000635:transmission / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000302:isolation & purification* / Q000472:pathogenicity; D005243:Feces / Q000382:microbiology; D005523:Food Supply; D005838:Genotype; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012703:Serotyping; D022621:Shiga Toxin / Q000096:biosynthesis* / Q000633:toxicity; D012987:Soil; D014867:Water
D001427:Bacterial Toxins; D012987:Soil; D014867:Water; D022621:Shiga Toxin