Scientists thought the “superbug” Staphylococcus aureus was a static organism, but time-lapse video shows signs of independent movement.
S. aureus, also known as MRSA, is a spherical bacterium with no propulsive tail or appendages. It can cause several infections in humans ranging from superficial to life threatening, which are difficult to treat because of antibiotic resistance.
Motility is central to bacterial behaviors, such as biofilm formation, virulence, and host colonization, so the discovery, published in Scientific Reports, could have implications for future clinical treatments.
“Our research has focused on observing the formation of dendrites–branch-like structures that emerge from the central colony of bacteria,” says Steve Diggle of the University of Nottingham’s School of Life Sciences.
“Using high powered microscopy, we saw that the bacteria can spread across the surface of an agar plate in structures that we have called ‘comets.’ These advance outwards and precede the formation of dendrites. We have observed and photographed the comets ’seeding' cells behind them, without losing mass, which then grow into observable dendrites.
“After 8 hours of colony growth, the comet heads are the main source of movement. Cells in the tail follow the comet heads for a while, while bacteria further away no longer move. Our time-lapse video shows the whole remarkable process.”
