2 
I believe that for an organism to be classified as an HV-1 host, 
let alone HV-2, it should differ from the wild type by a margin 
comparable to the difference between E.coli K12 and a wild type E.coli , 
and that is a large margin. To take as a specific example B.subtilis , 
I believe that any strain which is capable of sporulation should not be 
considered as an HV-1 host. In Europe, and also in the USA I understand, 
some wish to propose that certain B.subtilis strains which retain the 
ability to sporulate should be nevertheless classified as HV-1 hosts. 
In my opinion that would be a travesty . Since the efficacy of biological 
containment is one of the chief arguments for relaxing the guidelines, 
surely it would be intellectually dishonest as well as politically inept 
to lower the criteria of biological containment when other hosts than 
those derived from E.coli K12 are considered. 
I hasten to add that these are my personal opinions, and I apologize 
if this letter sounds like preaching but this question has already arisen 
in the EMBO Committee, where it was left unresolved, and marginally at a 
COGENE meeting. 
With my best regards. 
Yours sincerely , 
John Tooze 
[A-148] 
