No it isn’t. Reporting on allegations and other newsworthy topics is literally the joirnalists’ jobs. They aren’t liable for libel or slander as long as they are reporting in good faith. And almost by definition reporting on something someone else said is in good faith as long as you think that they think it’s true.
None of the things you’ve listed here are single molecules except for the prion. A single cell, even for simple organisms, is made up of millions of proteins. Viruses come close, but are still made up of the nucleus and the capsid.