Some E. coli set off viral grenades inside nearby bacteria
A toxin called colibactin awakens dormant viruses embedded in bacterial DNA

Some types of E. coli make a chemical warfare agent that may cause dormant viral bombs to go off in some neighboring bacteria. Researchers recently discovered this new type of microbial warfare, engaged in by bacteria similar to the lab-grown E. coli in this colorized, scanning electron microscope image.
NIAID, NIH/Flickr (CC BY-NC 2.0)