>He does not link it with a particular practice. The resistance could have
come from other bacteria through Lateral Gene Transfer.

Not a question of where the gene (or allele) came from--as I understand it,
oxytetracycline is a natural product of *Streptococcus rimosus*, so there
likely have always been resistant bacteria.  The question is selection
pressure.  So long as TM was applied only once or twice a season, and due
to the fact that it rapidly degrades in the hive, natural selection would
have favored nonresistant bacteria if there was a fitness cost to carrying
the genes for resistance during times of lack of exposure.

Only when an antibiotic is present continually would there be a major
fitness advantage to resistant bacteria.  The 24/365 application of
extender patties by some would have created such conditions.  I doubt that
it is mere coincidence that resistant AFB appeared shortly after that
practice became common.

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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