Clostridium difficile - Wikipedia

Clostridium difficile - Wikipedia: "Because the organism forms heat-resistant spores, it can remain in the hospital or nursing home environment for long periods of time. It can be cultured from almost any surface in the hospital. Once spores are ingested, they pass through the stomach unscathed because of their acid-resistance."

Heat-resistant, acid-resistant -- C. diff sounds pretty tough to stop.