Honeybees the world over are susceptible to the bacterial disease called "foulbrood", which can wipe out a hive faster than beekeepers can react to the infection. In the U.S., beekeepers have kept the disease at bay with regular preventive applications of the antibiotic oxytetracycline. Given what we now know about bacterial resistance, it seems reasonable to expect that honeybees carry bacteria with a plethora of antibiotic resistance genes.
A study in mBio this week shows that this expectation is correct: using diagnostic PCR and sequencing, the authors show that bacteria in the guts of honeybees are highly resistant to tetracycline, probably as a result of decades of preventive antibiotic use in domesticated hives. Yale researchers identified eight different tetracycline resistance genes among U.S. honeybees that were exposed to the antibiotic.
But here's the kicker: these antibiotic resistance genes were largely absent in bees from countries where such antibiotic use is banned. Countries like New Zealand, Switzerland, and the Czech Republic struggle with the same diseases, but they don't pump prophylactic oxytetracycline into their hives, so bees in those countries don't carry nearly the same diversity or density of resistance genes as U.S. bees do.
"It [resistance] seems to be everywhere in the U.S.," says Nancy Moran of Yale, a senior author on the study. "There's a pattern here, where the U.S. has these genes and the others don't."
Click on the source link to read more on mBio's blog, mBiosphere...