I have no reason to think Italians are more suseptible to AFB than any other strain of bee. I do wonder where you got your equipment from?
Being a first poster here, how long have you had bees?
How did you determine it was AFB? What signs did you see?
Did you buy a package of bees and put them on foundation or comb?
Did you buy a nuc? Most infections are bought. Unbeknownst to the seller usually. Or transfered unbeknownst to the beekeeper making the split.