Nerdular Nerdance had an interesting write-up on a strain of bacteria that feasts off of other bacteria.

The victim in this case was E. coli.

The “good” bacteria (called Myxococcus xanthus) literally ate up parts of the E. coli., rendering it harmless.

This discovery could lead to the production of good bacteria to seek out and destroy antibiotic resistant strains of harmful bacteria.

That is, until the good bacteria morphs into something harmful and destroys civilization as we know it.