Why are American foulbrood spores difficult to eliminate from infected hives?

American foulbrood is a severe disease affecting honeybee colonies, caused by the bacterium Paenibacillus larvae (formerly Bacillus larvae).12

The primary reason these spores are difficult to eliminate is their extreme resilience; they are highly resistant to both heat and chemical treatments. Because of this durability, the spores can persist in the environment and on beekeeping equipment for long periods, facilitating the spread of the disease to healthy colonies.2

Due to the difficulty of eradicating these persistent spores, many jurisdictions and U.S. states mandate the destruction of infected colonies by fire to prevent further transmission. While certain antibiotics have been used to control the disease, the inherent hardiness of the spores remains a significant challenge in animal husbandry and apiary management.2