Bourdeau RW, Lee-Gosselin A, Lakshmanan A, Farhadi A, Kumar SR, Nety SP, Shapiro MG.

Nature. 2018 Jan 3;553(7686):86-90. doi:10.1038/nature25021

Acoustic reporter genes for noninvasive imaging of microorganisms in mammalian hosts.

Bacterial gas containers reflect ultrasounds. Introduced by transgenesis, they were used to non-invasively detect bacteria in the gut of live animals.