The effect of thermal treatments on the viability and infectivity of Cryptosporidium parvum on beef surfaces.
OBJECTIVE
The aim of this research was to examine the effect of thermal treatments on the viability and infectivity of Cryptosporidium parvum oocysts attached to a beef surface.


RESULTS
This study examined the effects of heat treatment (60 or 75 degrees C) on the viability of C. parvum oocysts inoculated onto the surface of beef muscle estimated by vital dye assay. The infectivity of the oocysts was assessed against monolayers of HCT-8 cells. At 60 degrees C viability of the oocysts decreased from 100% at T0 to 64.2% at T60. At 75 degrees C the viability of the oocysts decreased from 100% at T0 to 53.7% at T15 and finally to 11.2% at T60. Oocysts were rendered noninfective against monolayers of HCT-8 cells following treatments of 60 degrees C/45 s and 75 degrees C/20 s.


CONCLUSIONS
The washing of carcasses with hot water and standard thermal treatments is sufficient to kill C. parvum on beef.


CONCLUSIONS
This study found that relatively mild heat, currently used to decontaminate and heat treat beef carcasses and to cook meat products, is capable of inactivating C. parvum.
Moriarty
E M
EM
The National Food Centre, Teagasc, Ashtown, Dublin, Ireland.
Duffy
G
G
McEvoy
J M
JM
Caccio
S
S
Sheridan
J J
JJ
McDowell
D
D
Blair
I S
IS
D000003:Abattoirs; D000818:Animals; D002417:Cattle; D002460:Cell Line; D002470:Cell Survival; D003457:Cryptosporidiosis / Q000517:prevention & control*; D016785:Cryptosporidium parvum / Q000254:growth & development*; D005511:Food Handling; D016266:Food Parasitology; D006358:Hot Temperature; D006801:Humans; D008460:Meat; D033661:Oocysts