Can germs develop surfactant resistance in a harmful way?

Never say never indeed!

a three part answer to the question:

1. Bacteria can develop resistance. These researchers did a screen for Staph and Pseudomonas which survived a detergent/soap treatment and indeed were able to select for many strains. I'm not sure that their explanation of why they are resistant is a final answer, especially for the Pseudomonas strains which have no hypothesis at all.

2. Nearly all bacteria do this all the time #1 Most bacteria can go into spore or plaque forms which basically hibernate. These plaque colonies are matrices of crosslinked bacteria and are resistant to extremes of conditions in the environment or lack of food.

3. Even Normal Resistance is a relative thing. Alcohol sanitizers kill 99.9% of bacteria. That sounds like a lot but that 0.1% can come back to full strength in a relatively short period of time. 0.1% is still millions of individuals surviving after a shower. Resistant bacteria have a higher proportion of survivors and should improve the bounce back rate. So resistance is a term which you need to define for a given situation.

Surfactant (soap) resistant bacteria can be nearly any sort of bacteria and a certain percentage of them are ready for a scrub down at any given time. To get a surface completely free of bacteria takes a good deal of work.

As far as a danger to human health - resistance to being killed by soap is a real problem because the few of them which also have resistance to antibiotics and are pathogenic will be pretty much unstoppable. Its not likely that surfactant resistance will itself make a bacteria pathogenic (never say never!) but if such a 'triple threat' emerges we'd all be in trouble.