The problem with the quote is Jonston neither invented the polymerase chain reaction (PCR) nor are most cold viruses DNA viruses (most are RNA).

Exactly. PCR is THE backbone of modern biology, I would suspect an author writing about it know at least what it is. I assume she meant 'adapted' instead of 'developed' but still, it sounds fishy and makes you unneccessarily question every other sentence of the article.

The reporter also called cholera a virus. You can't expect too much from science reporting in mainstream newspapers.

This is certainly true. Of course if they can't report science correctly what chance do they have on any other subject that I don't know about :)

Zero. Why people believe anything that's in mainstream news is beyond me.

The writer is mistaken, but cholera pathogenicity is caused by a virus. A temperate phage carries the genes for cholera toxin and infects cholera bacteria.