"E. amylovora" needs to be destroyed externally, before it enters the cell. This is simply because once it enters the host, it spreads during the endophytic phase of pathogenesis. Once this happens external control methods become ineffective. The ideal control method is to apply copper and antibiotics to the plant externally. This is the only effective method and it is indeed preventative. Currently it has been noted that "E. amylovora" has developed a resistance to the antibiotic streptomycin, as do most bacteria due to their flexible ability to transfer preferential genes promoting resistance to certain antibiotics horizontally from species not even similar to it as all bacteria can.