Each solution contains many types of phages, although usually just one attacks the bacteria.

BBC: Phages may be key in bacteria battle

Phages are parasites of bacteria, and the phage that Sequella works with specialises in M. tuberculosis.

ECONOMIST: A poor diagnosis

The phages are vehicles for delivering vaccine - in theory, against a number of diseases with a single shot.

BBC: Hope for cheaper, better vaccines

So I bought an old fridge, and I used to take all the phages home and keep them safe in my kitchen.

BBC: Phages may be key in bacteria battle