Some interesting points of view. Some more ground needs to be covered
   before this ends, so I'll type while thinking.
 
   The recent discussion so far seems to have accepted the premise that
   resistant AFB exists in Argentina but not elsewhere. Not necessarily so.
 
   As discussed a month or so ago, when this came up, a USDA study
   indicated that AFB in the U.S. in 1994 was no more resistant than
   cultures from decades ago, but there is evidence (still a few cases)
   this year, of OTC (oxytetracycline)-resistant AFB in the U.S. This is
   thought to perhaps have developed from the increased long-term use of
   antibiotic extender patties (related to mites). (continuous selection
   pressure).
   (By the way, lab tests by USDA indicate that the suspected resistant
   strain in the U.S. is not immune to OTC, but IS less susceptible. That
   brings up some questions: at what point do we call a strain resistant
   (statistical difference in lab vs non-responding in field); and whether
   the strain is on a short trip to immunity, or is there some mechanism
   that keeps it from losing all its susceptibility?). Questions that might
   be address by research, but probably will not, in today's environment.
 
   There is now increased interest in registering a new antibiotic (more
   acceptable than sulpha) to combat the resistant strain.
 
   Let's look at 2 scenarios:
        1 OTC is the only drug available.
        2 A new drug, effective against the OTC res strain, is available.
 
   If (when) infected hives of the resistant strain show up:
 
   Under scenario 1, the hives will be useless to any beekeeper, and will
   be destroyed. The resistant strain may have escaped partially, but will
   show up and be eliminated (not many unmanaged bees left these days). The
   conditions that lead to the development of the resistance will be an
   evolutionary dead end (drawn out over a few years, maybe). (This may
   have happened in various cases in the past. I've seen operations where
   infected hives were treated for years, but then became so infected it
   was clear they were not worth keeping).
 
   Under scenario 2, the non-responding hive(s) may be treated with the new
   antibiotic (by some beekeeper who doesn't believe in burning). This will
   suppress the damage, and vestiges of the new strain will survive (as
   susceptible AFB does now). If the "continuous exposure to antibiotic"
   practices that ( OK, presumably) created the resistant strain are
   continued with the new antibiotic, strains resistant to IT will quite
   possibly, (likely) show up within a couple of years, and we'll be in the
   same uncomfortable position.
 
   So, am I trying to say an alternative antibiotic should NOT be
   developed?
   No, just that a new antibiotic may not solve the problem for long, if
   there are new practices that created this new problem, and the practices
   are not changed first.
 
 
   Kerry Clark, Apiculture Specialist
   B.C. Ministry of Agriculture, Fisheries and Food
   1201 103 Ave
   Dawson Creek B.C.
        V1G 4J2  CANADA          Tel (250) 784-2231     fax (250) 784-2299
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