Ultrasound can now track bacteria in the body like sonar detects submarines.
For the first time, researchers have genetically modified microbes to form gas-filled pouches that scatter sound waves to produce ultrasound signals. When these bacteria are placed inside an animal, an ultrasound detector can pick up those signals and reveal the microbes’ location, much like sonar waves bouncing off ships at sea, explains study coauthor Mikhail Shapiro, a chemical engineer at Caltech.
This technique, described in the Jan. 4 Nature, could help researchers more closely monitor microbes used to seek and destroy tumors or treat gut diseases (SN: 11/1/14, p. 18).