Assessing the presence of BSE and scrapie in slaughterhouse wastewater.
OBJECTIVE
This paper describes a procedure for evaluating the presence and the stability of the proteinase K-resistant form of the prion protein (PrP(res)) in slaughterhouse wastewater.


RESULTS
Wastewater samples were spiked with either scrapie or bovine spongiform encephalopathy agents and PrP(res) was concentrated and detected by western blotting. The detection limit was estimated to be 2-4 microg of either scrapie or BSE-infected brain tissue in 15 ml of sewage. Wastewater samples from three abattoirs were analysed, two of which had processed BSE-infected animals. No PrP(res) was detected. The effect of sewage on the inoculum and the persistence of transmissible spongiform encephalopathy agents in wastewater were also considered.


CONCLUSIONS
The results of the assay suggest that wastewaters from abattoirs where one positive BSE case has been identified would contain titres lower than 0.6-26 x 10(-4) cattle oral ID(50) per litre resulting from specified risk material tissue contamination. Moreover, the effect of abattoir wastewaters is to reduce the persistence of PrP(res).


CONCLUSIONS
The assay may be a useful tool for risk assessment studies and for reducing the potential risk of contamination with BSE via sewage sludge fertilizer procedures.
Maluquer de Motes
C
C
Department of Microbiology, Universitat de Barcelona, Barcelona, Spain.
Simon
S
S
Grassi
J
J
Torres
J M
JM
Pumarola
M
M
Girones
R
R
D000003:Abattoirs; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000378:metabolism* / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D018620:PrPSc Proteins / Q000032:analysis* / Q000276:immunology; D012608:Scrapie / Q000378:metabolism* / Q000517:prevention & control; D012680:Sensitivity and Specificity; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid
D018620:PrPSc Proteins; D012722:Sewage