> In order to become resistant to steam, it would have to give up other things that it currently spends its "budget" on. Exactly this. When bacteria become r

> In order to become resistant to steam, it would have to give up other things that it currently spends its "budget" on. Exactly this. When bacteria become resistant to an antibiotic, they typically do so by giving up a metabolic pathway. If you take away the antibiotic, they usually quickly revert to the 'wild type' of bacteria. As for becoming resistant to steam, even if they could do it, once you stopped applying steam, then they'd probably be unable to survive at room temperature.