In order to adapt to their environments, it is important that bacteria be able to mix up their genetic code. One way that bacteria do this is by taking up bits of free-floating foreign DNA that can be released by other kinds of bacteria into their environments when they die. This process is called ‘transformation.’ The pieces of DNA can occasionally encode components that make bacteria better able to infect cells or degrade antibiotics, transforming them from harmless bacteria into dangerous ‘superbugs.’ However, how bacteria capture these pieces of foreign DNA has remained mysterious.
It has long been thought that bacteria use specialized arm-like extensions called pili to grab foreign DNA, but microbiologists have never been able to directly observe this process because pili are tiny and fleeting. However, researchers at Indiana University have now caught bacteria in their hunting expedition. New staining techniques have allowed scientists to visualize bacteria extending their pili, capturing the DNA, and retracting the pili to internalize the foreign material.
Bacteria that cause cholera and community-acquired pneumonias, for example, are so dangerous because of this ability to absorb foreign DNA, which contributes to the development of antibiotic resistance. Observing the pili-DNA binding process is a big step towards understanding how bacterial transformation occurs. And ultimately, this research might help scientists develop drugs to prevent the development of these superbugs by preventing the bacteria’s ability to transform. All in all, there’s a lot up for grabs.
Managing correspondent: Radhika Agarwal
Popular news article: New York Times
Original science article: Nature
Image Credit: Ankur Dalia/Indiana University