The TSE community reference laboratory strain typing expert group (STEG)
European Commission - MEMO/06/113 09/03/2006
Other available languages: none
Brussels, 9 March 2006
Summary of the STEG opinion on three isolates (05-0825 and 06-0017 from France; 204163425 from Cyprus) referred to the group following the identification of unusual molecular profiles on discriminatory Western blot (as required in EU Regulation 36/2005.)
Report drafted by MMS summarising the email consultation on available test data with the European members of the STEG
Three cases were referred to the STEG following the identification, in each case, of a low molecular weight unglycosylated band in discriminatory Western blot.
A full ring trial has not been possible for any of these cases.
Absence of a full panel of test results in ring trial means that even if there had been total conformity of interpretation, unequivocal categorization of the isolates would not be possible at this stage. However, it is clear from the results available (see table) that they do not all concur with the ‘BSE-like’ outcome of the primary differential screening blot, and consequently would not have been categorized as BSE-like even if all test methods had been applied.
The conclusions of the group, based on the data currently available, are as follows.
Dr Marion M Simmons
On behalf of the EU CRL for TSE (STEG)
8th March 2006
 There are some minor discrepancies between the glycoform profiles obtained from these samples and those of experimental ovine BSE. However, it is the consensus of the group that glycoform profile alone is not a robust discriminatory criterion.
 The result does not fit the criteria for ‘BSE-like’ by this ‘test’, 05-0825 and 06-0017 isolates show intermediate resistance to PK treatment which is quite common in a population of "classical" scrapie.
 The result does not fit the criteria for ‘BSE-like’ by this ‘test’, nor does it match those for classical scrapie isolates. It also does not share the properties of ‘atypical’ scrapie, as defined in the EFSA Opinion.