Survival of Escherichia coli O157 in abattoir waste products.
OBJECTIVE
This study monitored survival and growth of Escherichia coli O157 in ovine and bovine abattoir waste.


METHODS
Blood and gut contents were inoculated separately with cocktails of E. coli O157. Samples were stored aerophilically and microaerophilically at 5 degrees C, 15 degrees C and 30 degrees C to represent storage at different container depths and at extremes of UK ambient temperature.


CONCLUSIONS
Results showed survival of E. coli O157 was irrespective of oxygen content with no significant differences observed between aerophilic and microaerophilic environments. Numbers of E. coli O157 in ovine and bovine gut contents showed no change when stored at 5 degrees C and increased 1-2 log(10) at 15 degrees C and 30 degrees C in 28 h. In ovine and bovine blood, irrespective of storage temperature, there was a 0.5-2 log(10) reduction or no change in numbers except in ovine blood stored at 30 degrees C where the fall in numbers was followed by a 3 log(10) increase. In aged (stored at 4 degrees C for 18 h before spiking) bovine blood there was no significant change in numbers at 5 degrees C while at 15 degrees C there was 2 log(10) rise after 48 h. At 30 degrees C there was an initial 1 log(10) decrease in numbers followed by a 1 log(10) rise over the following 40 h.


CONCLUSIONS
Abattoir wastes may become contaminated from animals infected with Verocytotoxigenic E. coli O157 and in certain storage conditions these pathogens could significantly increase in numbers. There is need for care in abattoir waste disposal, not only for personnel subject to direct contact, but also in the prevention of cross contamination to adjacent land and water courses which could indirectly infect humans.
Applied Food Microbiology Group, Department of Medical Microbiology, University of Aberdeen, Foresterhill, UK.
N F
NF
Hepburn
M
M
MacRae
I D
ID
Ogden
D000003:Abattoirs; D000818:Animals; D001769:Blood / Q000382:microbiology; D002417:Cattle; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000302:isolation & purification; D007422:Intestines / Q000382:microbiology; D012756:Sheep; D013696:Temperature; D018505:Waste Management / Q000379:methods; D014866:Waste Products
D014866:Waste Products