Help w/ a BioFilm Question? Could it be the answer?

I have some questions about Biofilms I hope someone could answer.

When it comes to Candida, Bacteria, Virus, Parasites, if these things form a biofilm around it, will they still show up on a culture? or does the biofilm protect it and thus these can't be cultured out.

Plus, could it be why these things are so hard to kill??

Unless we rid these nasty beasties of their biofilms we can't touch them, get to them to kill them?

If this is true, how do we get rid of these biofilms??

What are these biofilms typically made of?? I read calcium, true? anything else?

Thanks!