Tim:

>....consider the terra-patties that are available inexpensively from Mann
Lake.

“There has been recent evidence in this country for bacterial resistance to
Terramycin. One of the suspected causes for this development is the sharp
increase in use by beekeepers of the medicated vegetable oil extender
patty. Bees do not always consume the patties rapidly which leads to a
situation in which antibiotic lingers in the hive for weeks or even months.
Resistance was not a problem in this country prior to the widespread use of
extender patties in the 1990s. For these reasons it is recommended that
Georgia beekeepers remove all uneaten portions of medicated extender
patties after patties have been in the hive for one month.”  There are a
few more remarks at the University of Georgia site:

http://www.ent.uga.edu/bees/Disorders/American_Foulbrood.htm

>I had one hive which had foul brood so bad that it stunk from outside the
hive, and probably a third of the brood was putrid. I treated with these
patties at the same time as with Checkmite

Was that IPM (Integrated Pesticide Management)?

>that was a mistake

I most certainly agree with that

>I couldn't remember which hive was infected, and all the hives were strong
and healthy.

Unfortunately the AFB spores are very likely still viable and will probably
reappear. Did you burn the equipment?

Regards,
Dick