Bacteria know how to cooperate and sacrifice for their kind

Collaboration and sacrifice are quite common in animals, not the " exclusive " behavior of humans. In the microscopic world, even small organisms like bacteria know how to apply that strategy to ensure the survival of the community.

The act of sacrificing one's own life to benefit the community is considered the highest manifestation of the spirit of cooperation.

Scientists from the Swiss Institute of Microbiology and the University of British Columbia (Canada) affirmed that cooperative behavior in self-destructive manner is essential to the survival of Salmonella typhimurium, a food-poisoning bacterium. Recently, more than 1,400 Americans have suffered from diarrhea, fever, typhoid and abdominal wall shrinkage after eating jalapeño pepper from Mexico.

Food poisoning starts to act when someone eats things that are contaminated with Salmonella. To cause poisoning, bacteria must enter the intestine. With the presence of a wide variety of microorganisms, the human digestive apparatus is a harsh environment for bacteria that intend to invade from outside. Even when defeating ' native ' microorganisms, they can still be destroyed by the human immune system.

Salmonella typhimurium (red) attacks cells in the intestinal wall. (Photo: Endiet.com)

Research has shown that Salmonella survives because of its collaborative coding strategy in its genes . All bacteria have identical gene structures, but they will split into two smaller groups.

After splitting, a group resides inside the cavity and waits, while the other group attacks the cells in the intestinal wall. When the cells are attacked, the body's immune system responds and the bacteria are killed. However, their sacrifice is not meaningless, as they can cause widespread infection to wipe out many intestinal microorganisms. When competitors disappear, the remaining bacteria can multiply to expand the scope of infection.

Two groups of bacteria have identical gene structures, but why do only a few tend to sacrifice themselves? The difference arises from the process of randomly arranging proteins and other molecules during the cell division phase. So all bacteria have genes that regulate self-destructive behavior, but only some express those genes.

Researchers think it is a reasonable adaptation. If two groups of bacteria have different gene structures, the genes that regulate the destructive behavior will quickly disappear. Instead, if a certain percentage of bacteria is ' programmed ' to accept sacrifices, their fellow humans will have a chance to survive (and those who accidentally put them into the stomach will have to pay a price).