I can see bees carrying the infected pollen from tree to tree (it's on the hairs on their body). The foragers are not in contact with the bee bread in the colony, not to mention the bee bread has gone through two fermentation cycles that hive overgrown any other bacteria. I seems doubtful that last year's bee bread is going to infect this years trees as that would involve the Erwinia amylovora bacteria surviving the fermentation process in the bee bread and then a forage (who has no interest in bee bread) coming into contact with the bee bread, getting it on it's hair (and the bee bread is not attracted to the hair on the bee as it is in a wet paste form, not a dry granular form) and then hauling it to your trees. This all seems very improbable. Not something the experts seem to think is relevant...
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7414.html
Yeast seems to prevent it (which is in bee bread):
http://en.wikipedia.org/wiki/Fire_blight
"Certain biological controls consisting of beneficial bacteria or yeast can also prevent fire blight from infecting new trees."
But careful pruning seems to be the solution of choice.
Another discussion on the topic:
http://www.beesource.com/forums/showthread.php?270121-Question-about-honey-bee-s-and-fire-blight
Some rules on bees being moved in UK and fire blight:
https://secure.fera.defra.gov.uk/beebase/index.cfm?pageid=103
http://www.stclareseeds.com/gardendisease/fire-blight.html
How about using bees to fight it?
inhabitat.com/scientists-use-bees-to-fight-fruit-tree-fire-blight/
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7414.html
Yeast seems to prevent it (which is in bee bread):
http://en.wikipedia.org/wiki/Fire_blight
"Certain biological controls consisting of beneficial bacteria or yeast can also prevent fire blight from infecting new trees."
But careful pruning seems to be the solution of choice.
Another discussion on the topic:
http://www.beesource.com/forums/showthread.php?270121-Question-about-honey-bee-s-and-fire-blight
Some rules on bees being moved in UK and fire blight:
https://secure.fera.defra.gov.uk/beebase/index.cfm?pageid=103
http://www.stclareseeds.com/gardendisease/fire-blight.html
How about using bees to fight it?
inhabitat.com/scientists-use-bees-to-fight-fruit-tree-fire-blight/