Dec 27, 2010 14:44 GMT  ·  By
Bacteria developed the first form of an immune system over millions of years of evolution
   Bacteria developed the first form of an immune system over millions of years of evolution

Bacteria have been alive on this planet for billions of years, and the main reason for that is this fact that they were able to adapt themselves to threats from other microorganisms, and also to drastic changes in their living conditions. A new study suggests other factors might be at play too.

A Texas A&M University scientist believes that part of the bacteria's evolutionary success is accounted for by their ability to harbor a primitive immune system, which enabled the organisms to incorporate genetic material from their worst enemies, viruses.

As this ability was obtained, bacteria became resistant to the action of different viruses. Another word for this is immune. The same basic mechanisms are at work in our immune systems as well.

Expert Thomas Wood, who holds an appointment as a professor at the A&M Artie McFerrin Department of Chemical Engineering, was the leader of the new investigation.

He published the results of the study in the latest issue of the multidisciplinary journal Nature Communications, which deals with research in biological, physical and chemical sciences.

The paper shows how bacterial microorganisms gained the ability to become resistant to viruses over millions of years, a trait that they are now using to fend off the effects of antibiotics.

Over millions of years of evolution, an amazing thing happened in bacterial chromosomes that were infected by viruses. While undoubtedly many populations perished following the infections, others thrived.

According to Wood, this happened because viral genetic material inside bacterial chromosomes is subjected to the same mutations as its host's genetic material is. Some of these mutations render the virus unable to replicate itself.

In addition, it was demonstrated that some bacteria species grew better once they had incorporated viral DNA into their chromosome than they did before.

“Over millions of years, this virus becomes a normal part of the bacterium. It brings in new tricks, new genes, new proteins, new enzymes, new things that it can do. The bacterium learns how to do things from this,” the expert explains.

“What we have found is that with this new viral DNA that has been trapped over millions of years in the chromosome, the cell has created a new immune system,” he argues.

“It has developed new proteins that have enabled it to resists antibiotics and other harmful things that attempt to oxidize cells, such as hydrogen peroxide,” the scientist goes on to say.

“These cells that have the new viral set of tricks don't die or don't die as rapidly,” he concludes.