E coli thriving in clean cattle
CATTLE which have been washed and appear clean can carry as many E coli 0157 bacteria as dirty cattle which would be rejected by an abattoir.
So warned Declan Bolton, research officer at Irelands National Food Centre, Dublin, speaking at last weeks Irish Ploughing Championships, Co Offaly. He was involved in a trial examining longevity and spread of E coli 0157 during slaughter.
"The bacteria lives for 81 days on grass and 188 days in a lab at 10C." That means that although a cowpat will be washed away long before the 81 days is up, the bacteria remains in grass – which may be grazed – until then. "E coli 0157 had a longer survival period than we expected and, in theory, that means grazing cattle could pick it up from infected animals."
To gauge spread through the slaughter process, infected faeces were applied to cattle rumps, then traced through the process. The bacteria was found on the carcass, knives, saws and the slaughtermans hands.
"We also washed off the infected faeces using a power washer before slaughter. But this seemed to wash bacteria into the hide and led to similar levels of E coli 0157 being detected."
• Irish Ploughing Championship report on p44.n