Mycoplasma pneumoniae is the causative agent of mycoplasma pneumonia.This bacterium attaches to human tissues and performs a "sliding motion" that slides around.The movement was discovered 80 years ago, but it was unclear what it was for.

　The research group focused on the water flow in the growing environment of mycoplasma.For example, the tracheal epithelium at the back of the human throat has a unidirectional flow from the lungs to the throat, and even if bacteria adhere to it, it is flushed out of the body.However, I thought that mycoplasma could move against the flow.

　When the behavior of bacteria in the water stream was observed with an optical microscope, the mycoplasma pneumoniae moved around the same place when there was no flow, but when the flow was given, it moved unidirectionally against the flow.This responsiveness is called positive runnability and is found in higher organisms such as fish, but the runnability of mycoplasma pneumoniae has been shown for the first time.

　The mechanism is similar to a weathercock looking upwind.When mycoplasma receives a flow, it rotates its buttock side while adhering to the surface at the tip of the membrane protrusion, and arranges the body in a direction opposite to the axis of the flow.

　Runaway is expected to contribute to the prevention and control of infectious diseases caused by this bacterium.Parasitic mycoplasmas cannot survive alone when flushed from the surface of the host.By going against the flow, it is thought that it will move to an environment suitable for survival.How much the running property discovered this time is actually involved in the infection process is an issue for the future.

Paper information:[PLOS Pathogens] Cell shape controls rheotaxis in small parasitic bacteria