I wholeheartedly yet respectfully disagree with throwing out the seed.
If your beans survived whatever killed them for long
enough to produce seed, save it. Seed saved from them, planted next year, will have more resistance. Consistent seed saving, and careful selection, every year, will lead you to disease-free cultivars.
The disease is not transmitted through the seed's genes. Only resistance is passed on. Weakness fails. If you plant the same old seed next year, instead of the new saved seed, you'll get the same problem no matter what you do to your soil.
It can take a few generations, but the patience pays off in a resistant bean. Save the biggest and healthiest in appearance... no genetic testing necessary... just go by what looks good. By doing this, I have tomatoes that are affected by nothing, and green beans that survive spring frost, for two examples.
This is how it has been done since man learned to plant seeds.