Bacteria swim and sense their surroundings with a single piece of anatomy
To walk down the street, your body employs over 25 muscle groups to control your gait and keep you upright. If you happen to bump into something, your foot has between 100,000 to 200,000 nerve endings in the sole alone to capture an enormous amount of detail about what you just hit. This works for us, but there are simpler ways to get around. After all, even lone bacteria can propel themselves through the world, making due with minimal sensory information. Exactly how that was all done with a single cell actually been a bit of a mystery, but researchers from the University of Basel have finally found how these tiny organisms interact with their environment.
The key feature in bacterial navigation is a long tendril extending from the cell membrane called the flagellum. As long as the bacteria is in some kind of liquid, from saliva to water to mucus, the flagellum spins, pushing the bacterium around like a stringy propeller on an outboard motorboat engine. It’s movement is powered by a stream of protons entering the cell, at least until it hits something.
Sticking a landing
When the bacterium comes in contact with a solid surface, the flagellum reveals its secondary function: a sensory “organ.” When the flagellum hits something, the the wall of your sinuses, the flow of protons is disrupted, which triggers further reactions inside the cell. Aside from the flimsy propeller being slowed down, the change in proton movement tells the bacterium to create an adhesive, which it then uses to anchor itself to that solid surface. In just a few seconds of contact, the bacterium is setting itself up to potentially launch an infection in the tissue it just bumped into.
Researchers hope that by understanding how bacteria initiate infections, we may be able to develop the means to disrupt them. This study was done with harmless Caulobacter bacteria, but the method of propulsion and mechanical sensitivity is probably used by many species of bacteria, including those that cause health problems in humans. With any luck, further research will allow us to prevent or at least slow this anchoring process, offering new forms of treatment as an alternative to our weakening library of antibiotics.
Source: Bacteria have a sense of touch