Researchers from The Universities of Nottingham showed a time lapse video of a superbug moving independently and spontaneously. The methicillin-resistant Staphylococcus aureus or MRSA was previously thought to be non-motile.
MRSA is responsible for various infections, some of which are life-threatening because they are resistant to methicillin. For the first time, researchers showed the spherical bacterium S. aureus has active motility despite not having appendages or a propulsive tail.
The latest research led by Dr. Steve Diggle focused on the dendrites formation, which are branch-like arrangements that stem from the bacteria's central colony. Diggle is from the university's School of Life Sciences.
The research team analyzed the dendrite formation using high powered microscopy and found that the S. aureus can crawl on an agar plate. The researchers dubbed the pre-dendrite structures as comets. The documented photographs and video showed the comets seeding cells in a trail behind them, continuously and without losing any mass. The trail of cells then forms into 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," said Diggle, who highlighted the documented the process in the time lapse video.
The comet heads are made up of S. aureus cell clusters. They have no observable flagella or appendages, but a slime pattern keeps these cell clusters together. The movement was observed on top of an agar plate and during some conditions, researchers found the comet heads can also scrape the agar surface and leave tracks behind.
Amazingly, moving S. aureus colonies can avoid other moving colonies. When the researchers tried to add fluid, the comet heads did not move effectively, but the cells at the comet's tails were able to move easily.
"It is amazing how the S. aureus cells can stick together and then stay together whilst moving over distances that are incredibly vast compared to the size of the individual cells," said Dr. Eric Pollitt, a member of the research team.
Motility plays a vital role in bacterial behaviors such as virulence (the ability of the organism to cause disease), biofilm formation and host colonization. The findings could be useful in developing new vaccines that would target MRSA's motility mechanism.
MRSA's newly documented behaviors looked similar to gliding motility. When true motility is proven, the study will also prove that S. aureus is the first Gram-positive bacterium that has a Gram-positive cell wall, which can move despite the absence of a flagella.
The study paved the way for more research on other Gram-positive bacteria that may have underlying motile mechanisms. The research was published in the journal Scientific Reports last Friday.
About MRSA
Also known as the superbug, the MRSA has resistance to various antibiotics. S. aureus is a common bacteria that can cause skin infections such as impetigo and boils. When the bacteria penetrate the skin, it can cause deadly infections such as endocarditis or blood poisoning.
Infection can be transmitted through skin-to-skin contact or through touching contaminated items such as clothes, towels, bed sheets and other various surfaces.
MRSA infection is most common in hospital settings due to the large presence of patients. It is also capable of entering the body through urinary catheter or other surgical wounds. Patients with severe health problems are the most vulnerable to the bacterial infection.
MRSA Symptoms
Staph infections appear as a pus-filled bump on the skin surface. The painful bump can appear swollen, red and warm to the touch. Staph infections, which include MRSA infections, can be accompanied by fever. Many people mistake staph infections for spider bites. However, unless an actual bite mark is observed, a suspicious swollen bump on the skin could be a staph infection.
